Catheter-Tract Metastases

Transcription

Catheter-Tract Metastases
CHEST
Catheter-Tract Metastases
Associated With Chronic
Indwelling Pleural Catheters*
Sam M. Janes, MBBS, PhD, MRCP;
Najib M. Rahman, BM BCh, MA, MRCP;
Robert J. O. Davies, DM, FRCP; and
Y. C. Gary Lee, MBChB, PhD, FCCP
Indwelling pleural catheters are increasingly being
used for ambulatory treatment of malignant pleural
effusion, particularly for patients unsuitable for
pleurodesis. These catheters are often left in situ for
the rest of the patient’s life. Tumor metastasis along
the tract between pleura and skin surface is a potential complication in patients with chronic indwelling
pleural catheters that has seldom been reported. We
describe four cases of catheter-tract metastasis that
developed between 3 weeks and 9 months after
catheter insertion. Catheter-tract metastasis occurred in two patients with mesothelioma despite
prophylactic irradiation at time of insertion, and in
two patients with metastatic adenocarcinoma. All
cases were successfully treated using external-beam
radiotherapy without necessitating catheter removal. A retrospective audit in our center showed
that catheter-tract metastasis occurred in 6.7% of 45
patients treated with indwelling pleural catheters for
*From the Centre of Respiratory Research (Drs. Janes and Lee),
University College London, UK; and Oxford Pleural Unit (Drs.
Rahman and Davies), Oxford Centre for Respiratory Medicine
and University of Oxford, Oxford, UK.
Dr. Janes is supported by a Medical Research Council Clinician
Scientist Fellowship, Dr. Lee is supported by a Wellcome
Advanced Fellowship, and Dr. Rahman is supported by a Medical Research Council Training Fellowship.
Drs. Janes and Rahman do not have any conflict of interests or
involvement with organizations with financial interests in the
subject matter. Drs. Davies and Lee have been awarded a project
grant from the British Lung Foundation to compare conventional
pleurodesis with chronic indwelling pleural catheters in patients
with malignant pleural effusions. The investigators of the trial
have accepted an arrangement to use pleural catheters provided
for free by Rocket Med plc (UK), since the acceptance of this
manuscript for publication. None of the investigators received
any funding from the company.
Manuscript received September 24, 2006; revision accepted
November 10, 2006.
Reproduction of this article is prohibited without written permission
from the American College of Chest Physicians (www.chestjournal.
org/misc/reprints.shtml).
Correspondence to: Y. C. Gary Lee, MBChB, PhD, FCCP,
Oxford Centre for Respiratory Medicine, Churchill Hospital,
Oxford OX3 7LJ, UK; e-mail: [email protected]
DOI: 10.1378/chest.06-2353
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Selected Reports
malignant pleural effusions. Both clinicians and patients should be aware of this potential complication.
(CHEST 2007; 131:1232–1234)
Key words: adenocarcinoma; indwelling catheter; mesothelioma; metastases; pleura
pleural effusions are common in clinical
M alignant
practice. Indwelling pleural catheters have increas1
ingly been advocated for management of recurrent effusions, especially in patients unsuitable for pleurodesis, or
in whom pleurodesis has failed.1–5 These catheters are
often left in situ for the rest of the patient’s life.
Tumor metastases from the parietal pleura to the skin
surface following tracts from pleural procedures (eg, thoracoscopy) are known complications of mesothelioma but
are rare with other malignancies.1 Patients with chronic
indwelling pleural catheters are at continual risks of tumor
spread along catheter tracts. Catheter-tract metastasis has
seldom been reported, and its incidence is unclear. We
report a series of four patients with catheter-tract metastasis from indwelling pleural catheters: two patients with
adenocarcinoma, and two patients with mesothelioma.
Case Report
A large left pleural effusion developed in a 61-year-old woman
(Fig 1, 2) 4 months after a left pneumonectomy and chest wall
Figure 1. Chest radiograph from the initial presentation showing a large left pleural effusion in the postpneumonectomy space.
Selected Reports
Retrospective Audit
The above case prompted a retrospective audit of the
incidence of catheter-tract metastases from indwelling
PleurX catheters in the Oxford Pleural Unit. Between
June 2002 and February 2006, 45 PleurX catheters were
inserted for drainage of malignant pleural effusions. All
patients were followed up by the unit, and any cathetertract metastases were recorded.
Catheter-tract metastasis developed in 3 of 45 patients
(6.7%) [Table 1]. The incidence appeared higher in
mesothelioma patients (2 of 15 patients, 13.3%) than in
those with metastatic carcinomas (1 of 30 patients, 3.3%).
Both of the patients with mesothelioma had such metastases despite prophylactic irradiation within 2 weeks of
catheter placement. Tract metastasis developed after 6
months in two patients and 9 months in the third patient.
All three patients were successfully treated with radiotherapy with the drain in situ, and the indwelling catheters
continued to function well.
Figure 2. Contrast-enhanced thoracic CT scan demonstrating
diffuse tumor involvement of the pleural surface.
resection for lung adenocarcinoma and preoperative chemotherapy. She had significant symptomatic relief after drainage of
pleural fluid, which tested positive for malignant cells. Despite
second-line chemotherapy with docetaxel, the effusion reaccumulated rapidly and required frequent drainage. Given the prior
pneumonectomy, pleurodesis was regarded as inappropriate.
Instead, a small-bore indwelling pleural catheter (PleurX; Denver
Biomedical; Golden, CO) was inserted for ambulatory fluid
drainage, with good symptomatic effect. Three weeks later, a
tumor nodule developed (Fig 3) at the catheter insertion site.
This was treated with external-beam radiotherapy (21Gy in three
fractions) administered while the catheter remained in situ.
Radiotherapy did not affect the function of the catheter. The
nodule resolved and was replaced by scar tissue 2 weeks after
irradiation. No new nodules developed in the subsequent 3
months of follow-up.
Figure 3. Tumor nodule growing through the chest wall at the
indwelling catheter site.
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Discussion
We report four cases of catheter-tract metastasis in
patients with pleural malignancies managed with indwelling pleural catheters. Our series include two cases of tract
metastasis from adenocarcinomas: a complication seldom
reported with cancers other than mesothelioma. In addition, we have shown that catheter-tract metastasis can be
treated with external-beam irradiation with the catheter in
situ. Prophylactic radiotherapy to the insertion site did not
prevent metastasis from indwelling catheters in the two
patients with mesothelioma.
Ambulatory drainage of recurrent malignant effusions
using small-bore indwelling pleural catheters is increasingly
used worldwide for the management of malignant pleural
effusions, especially in patients who failed pleurodesis, have
trapped lungs, or have a limited life expectancy.1 The use of
these catheters is generally safe, but the full spectrum of
potential side effects has not been established.
The parietal pleura is often affected in malignant
pleural diseases.1 Needle tract metastasis along previous
pleural puncture sites is well established with mesothelioma, and occurs in up to 40% of patients.5 However,
metastasis from adenocarcinomas along pleural puncture
sites are uncommon.
Catheter-tract metastasis with indwelling pleural catheters has rarely been reported. In three large series of a
combined 374 patients,2– 4 only two cases were described.
In our population, catheter-tract metastasis occurred in
6.7% of patients who received PleurX catheters.
Prophylactic irradiation of the pleural puncture sites
is effective in preventing needle tract metastases from
mesothelioma following “one-off” pleural procedures
(eg, thoracostomy or thoracoscopy). However, radiotherapy may offer limited protection against ongoing
risks of malignant invasion in patients with long-term
indwelling pleural catheters. This may explain the development of catheter-tract metastases despite prophylactic radiotherapy in our two mesothelioma patients.
External-beam radiotherapy was effective in treating
CHEST / 131 / 4 / APRIL, 2007
1233
Table 1—Details of the Three Patients With Catheter-Tract Metastasis From the Retrospective Audit
Patient
No.
Histologic
Tumor Type
Insertion of PleurX
Catheter After
Diagnosis, mo
Tract Metastasis
After Insertion,
mo
Prophylactic
Radiotherapy
1
Mesothelioma
1.5
10 d after PleurX
insertion
7
2
Epithelioid mesothelioma
1
9
3
Poorly differentiated
adenocarcinoma of
unknown primary
5 d after PleurX
insertion
Not given
11
the catheter-tract metastases. Irradiation was performed with
the catheter in situ without impairing the catheter drainage.
In summary, catheter-tract metastasis can develop with
both metastatic carcinomas and mesothelioma. The incidence is frequent enough that patients should be warned
of this potential complication. Larger series are required
to establish the incidence and risk factors for cathetertract metastasis.
References
1 Lee YCG, Light RW. Management of malignant pleural
effusions. Respirology 2004; 9:148 –156
2 Tremblay A, Michaud G. Single-center experience with 250
tunnelled pleural catheter insertions for malignant pleural
effusion. Chest 2006; 129:362–368
3 Putnam JB Jr, Walsh GL, Swisher SG, et al. Outpatient
management of malignant pleural effusion by a chronic
indwelling pleural catheter. Ann Thorac Surg 2000; 69:369 –
375
4 Musani AI, Haas AR, Seijo L, et al. Outpatient management
of malignant pleural effusions with small-bore, tunneled
pleural catheters. Respiration 2004; 71:559 –566
5 Boutin C, Rey F, Viallat JR. Prevention of malignant seeding
after invasive diagnostic procedures in patients with pleural
mesothelioma: a randomized trial of local radiotherapy. Chest
1995; 108:754 –758
8
Treatment for Tract
Metastasis
Time of Death
After Insertion,
mo
Radiotherapy at 30 Gy in
six fractions (2 mo after
initial metastasis)
Low-dose palliative
radiotherapy
Radiotherapy (30 Gy in six
fractions) and catheter
removal 2 mo after initial
metastasis
17
12
22
pneumonia-like symptoms that did not respond to
treatment with antibiotics. Their chest radiographs
revealed bilateral diffuse infiltrates. The diagnosis of
AEP was established based on the clinical picture,
BAL that revealed an average eosinophil count
> 45%, and immediate clinical improvement after
introducing corticosteroids. All other possible causes
were excluded during the initial workup.
(CHEST 2007; 131:1234 –1237)
Key words: eosinophils; pneumonia; smoking
Abbreviation: AEP ⫽ acute eeosinophilic pneumonia
eosinophilic pneumonia (AEP) is characterized
A bycuteeosinophilic
infiltration in the lungs, respiratory
distress, a rapid therapeutic response to corticosteroids,
and the absence of relapse.1 Cigarette smoking has been
recognized to cause AEP, and a report2 from Japan has
demonstrated an association of cigarette smoking-induced
AEP with menthol-flavored cigarettes. Based on review of
two cases of AEP following flavored cigar smoking, we
believe that the flavoring component may have a major
rule in precipitating the illness.
Case Reports
Case 1
Flavored Cigar Smoking
Induces Acute Eosinophilic
Pneumonia*
Nawar Al-Saieg, MD; Ousama Moammar, MD; and
Ritha Kartan, MD, FCCP
Two cases of acute eosinophilic pneumonia (AEP)
following smoking of flavored cigars were analyzed
for characteristic features. None of our patients had
a history of smoking flavored cigars/cigarettes in the
past. One of them had never smoked, and the second
patient was an ex-smoker who quit 17 years ago.
Both patients presented with community-acquired
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A previously healthy 23-year-old man presented to the emergency
department with a 5-day history of shortness of breath and exercise
intolerance. The patient reported a relatively sudden onset of a
*From the Department of Internal Medicine, Western Reserve
Care System/Northeastern Ohio Universities College of Medicine, Youngstown, OH.
This work was performed at Western Reserve Care System,
Youngstown, OH.
The authors have no conflicts of interest to disclose.
Manuscript received October 27, 2006; revision accepted November 21, 2006.
Reproduction of this article is prohibited without written permission
from the American College of Chest Physicians (www.chestjournal.
org/misc/reprints.shtml).
Correspondence to: Nawar Al-Saieg, MD, Department of Internal Medicine, Western Reserve Care System, 500 Gypsy Ln,
Youngstown, OH 44501; e-mail: [email protected]
DOI: 10.1378/chest.06-2623
Selected Reports
Figure 1. Chest CT showing a small, right-sided pleural effusion, minimal pleural reaction on the left, and patchy parenchymal infiltrates in both lung fields.
productive cough of yellowish sputum accompanied by fever, chills,
and dyspnea on minimal exertions. The patient also reported mild
headache, loss of appetite, and generalized weakness prior to
hospital admission. The patient started smoking strawberry-flavored
cigars 3 weeks prior to admission, approximately four cigars weekly.
There was no history of any other form of tobacco or alcohol abuse
or any recreational drug use. In the emergency department, the
patient had a temperature of 38.3°C, BP was 129/74 mm Hg, pulse
rate was 126 beats/min, and respiration rate was 22 breaths/min.
Blood oxygen saturation was 88% on room air. Physical examination
showed coarse crackles posteriorly in both lungs. There was no use
of accessory muscles. Laboratory findings revealed WBC count of
14,250/␮L; polymorphonuclear leukocytes, 75%; lymphocytes, 10%;
eosinophils, 8%; and monocytes, 3%. By hospital day 5, eosinophil
fraction had increased to 26%. Chest radiography showed diffuse
bilateral pulmonary infiltrates. The chest CT showed a small rightsided pleural effusion, minimal pleural reaction on the left and
Figure 2. Chest radiograph showing diffuse bilateral infiltrate
greater on the right side.
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Figure 3. CT of the chest revealing bilateral diffuse infiltrates
with small bilateral pleural effusions.
patchy parenchymal infiltrates in both lung fields (Fig 1). The
patient was started on ceftriaxone and azithromycin and then was
switched to moxifloxacin without any improvement. Video bronchoscopy was performed and showed diffuse inflammation with copious
watery secretions. There was no evidence of endobronchial tumors.
BAL showed nucleated cells at 738/␮L; eosinophils, 72%; and
lymphocytes, 15%. All bacterial, viral, and fungal study results were
negative. The patient received IV methylprednisolone after stopping
antibiotics and improved dramatically within 24 h. Chest radiography demonstrated remarkable resolution of the infiltrates after
steroids. The patient was discharged on a tapering dose of oral
prednisone.
Case 2
The second case was a 53-year-old white man with a medical
history significant for coronary artery disease, diabetes mellitus type
2, and hypercholesterolemia. A history of allergy to strawberries was
reported. The patient presented to the emergency department with
Figure 4. Chest radiograph revealing remarkable resolution of
the infiltrates.
CHEST / 131 / 4 / APRIL, 2007
1235
a 2-day history of chest tightness, dry cough, and dyspnea. He
reported a new onset of night sweats, chills, and wheezing. The
patient denied any sick contact, recent travel, or weight loss. The
patient visited his family doctor’s office 3 days prior to hospital
admission and was started on azithromycin without any improvement. He quit smoking 17 years ago, but 3 weeks prior to hospital
admission he restarted smoking different types of flavored cigars. On
examination, the patient was found to be febrile with a temperature
of 38.1°C, a heart rate of 120 beats/min, and blood oxygen saturation
of 92% on 3 L/min of oxygen; later on, the oxygen saturation went
down and the patient required 100% oxygen. Lung examination
revealed bilateral crackles. There was no use of accessory muscles.
Laboratory findings were WBC count of 17,400/␮L; polymorphonuclear leukocytes, 91%; lymphocytes, 1%; eosinophils, 4%; and
monocytes, 2%. By hospital day 5, eosinophil fraction had increased
to 33%. Diffuse bilateral infiltrate greater on the right side was noted
on chest radiograph (Fig 2). CT of the chest revealed bilateral
diffuse infiltrates with small bilateral pleural effusions (Fig 3). At that
point, the patient was admitted to the hospital and treated for
community-acquired pneumonia with moxifloxacin without improvement. Video bronchoscopy clearly showed an inflamed mucosa
of the left bronchial tree. There was no mass or any evidence of
consolidation. BAL showed nucleated cells at 31,500/␮L; eosinophils, 49%; and lymphocytes, 16%. The patient was started on IV
methylprednisolone and improved dramatically after introducing the
steroid treatment. Chest radiography revealed remarkable resolution of the infiltrates in the next few days (Fig 4). The patient was
discharged on a tapering dose of oral prednisone.
Discussion
The cause of AEP remains unknown. Some investigators3
have suggested that AEP is an acute hypersensitivity reaction
to an unidentified inhaled antigen. Patients usually present
with an acute febrile illness of ⬍ 3 weeks in duration, and in
most cases the duration of symptoms is ⬍ 7 days. Nonproductive cough and dyspnea are present in almost every
patient. Associated symptoms and signs include malaise,
myalgias, night sweats, pleuritic chest pain, and hypoxemic
respiratory insufficiency. Physical examination usually shows
fever and tachypnea. Bibasilar inspiratory crackles and occasionally rhonchi on forced exhalation are heard on auscultation of the chest.4,5 Patients generally present with an initial
neutrophilic leukocytosis.2,6 In most cases, the eosinophil
count becomes markedly elevated during the subsequent
course of AEP.5–7 Patients with AEP are uniformly responsive to IV or oral corticosteroid therapy.5 The response is
often dramatic, occurring within 12 to 48 h, and there is no
relapse following withdrawal of the steroids. The present two
cases met the criteria for a diagnosis of AEP by Allen and
Davis8: an acute febrile illness of short duration (usually ⬍ 1
week), hypoxemic respiratory failure, diffuse pulmonary
opacities on chest radiograph, BAL eosinophilia ⬎ 25%, lung
biopsy evidence of eosinophilic infiltrates, and absence of
known causes of eosinophilic pneumonia, including drugs,
infections, or asthma. We have excluded all possible causes in
the initial workup.
In reviewing the literature, one study2 reported flavored
cigarettes, specifically menthol flavored, as the underlying
cause of cigarette smoking-associated AEP. Other reports
have associated AEP with World Trade Center dust exposure,9 as well as military personnel having this complication in
Iraq after significant exposure to fine airborne sand or dust.10
In our first case, the patient was a nonsmoker and started
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smoking flavored cigars for the first time 3 weeks prior to
hospital admission. It is difficult in this case to make a clear
assumption that AEP was most likely induced by the chemical substances used for flavoring the cigar. However, smoking itself could be the triggering factor of AEP, as it has been
implicated in previous reports,11–14 and proven by a smoking
challenge test. For that test, the patient was asked to smoke
20 cigarettes a day for 13 days. The challenge test reproduced
typical BAL and transbronchial lung biopsy changes of AEP,
but the patient had neither radiologic changes nor symptoms
after the challenge test.15 We did not perform a smoking
challenge test on our patients.
The second patient was an ex-smoker and had no documented history of pneumonia. The patient stopped smoking
17 years ago and resumed smoking 3 weeks prior to hospital
admission, trying different types of flavored cigars. Because
of a longstanding history of smoking without any history of
documented respiratory events related to smoking cigarettes,
we suspected a major rule of flavoring components in
inducing his AEP. These cases illustrate the increasing
evidence that cigarette/cigar smoking could be indeed a
major factor in inducing AEP. More importantly, it demonstrates the importance of a detailed medical and smoking
history to identify flavored cigar as a probable cause of AEP.
More extensive investigation and research is needed to reach
a solid conclusion regarding the actual rule of flavoring
cigar/cigarette in inducing AEP.
References
1 Allen JN, Pacht ER, Gadek JE, et al. Acute eosinophilic
pneumonia as a reversible cause of noninfectious respiratory
failure. N Engl J Med 1989; 321:569 –574
2 Miki K, Miki M, Nakamura Y, et al. Early-phase neutrophilia
in cigarette smoke induced acute eosinophilic pneumonia.
Intern Med 2003; 42:839 – 845
3 Badesch DB, King TE Jr, Schwarz MI. Acute eosinophilic
pneumonia: a hypersensitivity phenomenon? Am Rev Respir
Dis 1989; 139:249 –252
4 Ogawa H, Fujimura M, Matsuda T, et al. Transient wheeze:
eosinophilic bronchobronchiolitis in acute eosinophilic pneumonia. Chest 1993; 104:493– 496
5 Jantz MA, Sahn SA. Corticosteroids in acute respiratory
failure. Am J Respir Crit Care Med 1999; 160:1079 –1100
6 Philit F, Etienne-Mastroianni B, Parrot A, et al. Idiopathic
acute eosinophilic pneumonia: a study of 22 patients. Am J
Respir Crit Care Med 2002; 166:1235–1239
7 Hayakawa H, Sato A, Toyoshima M, et al. A clinical study of
idiopathic eosinophilic pneumonia. Chest 1994; 105:1462–
1466
8 Allen JN, Davis WB. Eosinophilic lung disease. Am J Respir
Crit Care Med 1994; 150:1423–1438
9 Rom WN, Weiden M, Garcia R, et al. Acute eosinophilic
pneumonia in a New York City firefighter exposed to World
Trade Center dust. Am J Respir Crit Care Med 2002;
166:797– 800
10 Shorr AF, Scoville SL, Cersovsky SB, et al. Acute eosinophilic
pneumonia among US military personnel deployed in or near
Iraq. JAMA 2004; 292:2997–3005
11 Shintani H, Fujimura M, Yasui M, et al. Acute eosinophilic
pneumonia caused by cigarette smoking. Intern Med 2000;
39:66 – 68
12 Shiota Y, Kawai T, Matsumoto H, et al. Acute eosinophilic
Selected Reports
pneumonia following cigarette smoking. Intern Med 2000;
39:830 – 833
13 Nakagome K, Kato J, Kubota S, et al. Acute eosinophilic
pneumonia induced by cigarette smoking [abstract in English]. Nihon Kokyuki Gakkai Zasshi 2000; 38:113–116
14 Godding V, Bodart E, Delos M, et al. Mechanisms of acute
eosinophilic inflammation in a case of acute eosinophilic
pneumonia in a 14-year-old girl. Clin Exp Allergy 1998;
28:504 –509
15 Watanabe K, Fujimura M, Kasahara K, et al. Acute eosinophilic pneumonia following cigarette smoking: a case report
including cigarette-smoking challenge test. Intern Med 2002;
41:1016 –1020
Corynebacterium ulcerans
Infection of the Lung
Mimicking the Histology of
Churg-Strauss Syndrome*
Key words: Churg-Strauss syndrome; Corynebacterium ulcerans; eosinophil
Abbreviation: CSS ⫽ Churg-Strauss syndrome
orynebacterium ulcerans is a veterinary pathogen.
C Nearly
all human cases are characterized by pharyn-
geal infections mimicking classical diphtheria.1 Cases of C
ulcerans infection in human lung are extremely rare.2,3 In
this article, we present a case of C ulcerans infection with
multiple lung cavities and nodules. Histologic findings
mimicked Churg-Strauss syndrome (CSS). All lung lesions
responded dramatically to antibiotics, and the patient
recovered.
Case Report
In October 2005, a 50-year-old man was admitted to our
hospital for high-grade fever up to 39°C, productive cough,
dyspnea on effort, general fatigue, and weight loss continuing
from 2 weeks previously. He had a duodenal ulcer at 15 years of
age but was otherwise healthy.
Shin-ichi Nureki, MD, PhD; Eishi Miyazaki, MD, PhD;
Osamu Matsuno, MD, PhD; Ryuichi Takenaka, MD;
Masaru Ando, MD, PhD; Toshihide Kumamoto, MD, PhD;
Tadao Nakano, PhD; Kiyofumi Ohkusu, PhD; and
Takayuki Ezaki, MD, PhD
We report the first case of pulmonary Corynebacterium ulcerans infection mimicking Churg-Strauss
syndrome (CSS). Productive cough, fever, general
fatigue, and weight loss developed in a 50-year-old
man. Laboratory data revealed prominent eosinophilia and elevated serum IgE. On chest images,
multiple nodules and cavities were predominantly
detected in the right lung. Histopathologic examination showed necrotizing granulomas and vasculitis
with massive eosinophilic infiltration identical to the
findings seen in CSS; however, clusters of Grampositive, coryneform rods were observed in the alveolar spaces. A toxigenic strain of C ulcerans was
isolated from lung tissue. The patient was treated
with antibiotics, and a favorable clinical course
ensued.
(CHEST 2007; 131:1237–1239)
*From the Divisions of Pulmonary Disease (Drs. Nureki,
Miyazaki, Matsuno, Takenaka, and Ando) and Neurology and
Neuromuscular Disorders (Dr. Kumamoto), Third Department
of Internal Medicine, Oita University Faculty of Medicine, and
Clinical Laboratory Center of Oita University Hospital (Dr.
Nakano), Yufu; and Department of Microbiology, Regeneration,
and Advanced Medical Science (Drs. Ohkusu and Ezaki), Gifu
University Graduate School of Medicine, Gifu, Japan.
The authors have no conflicts of interest to disclose.
Manuscript received September 22, 2006; revision accepted
December 11, 2006.
Reproduction of this article is prohibited without written permission
from the American College of Chest Physicians (www.chestjournal.
org/misc/reprints.shtml).
Correspondence to: Shin-ichi Nureki, MD, PhD, Division of
Pulmonary Disease, Third Department of Internal Medicine, Oita
University Faculty of Medicine, 1–1 Idaigaoka, Hasama-machi,
Yufu, Oita 879-5593, Japan; e-mail: [email protected]
DOI: 10.1378/chest.06-2346
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Figure 1. Top, A: Posteroanterior chest radiograph showing
multiple nodules and cavities, predominantly in the right lung.
Bottom, B: Chest CT showing multiple cavity nodules associated
with bronchiectasis.
CHEST / 131 / 4 / APRIL, 2007
1237
On hospital admission, the patient’s temperature was 37.6°C
(maximum, 39.3°C on the same day), pulse rate was 100 beats/
min, and respiratory rate was 16 breaths/min. Coarse crackles
were heard over both lung fields. Laboratory data on hospital
admission included WBC count of 26,500/␮L, with 50.4% neutrophils and 37.5% eosinophils, and C-reactive protein of 10.82
mg/dL. Serum IgE concentration was elevated to 1,424 IU/mL.
Anti-neutrophil cytoplasmic antibodies were negative. Blood,
sputum, and BAL fluid cultures findings, including Mycobacterium tuberculosis and fungi, were negative.
A chest radiograph showed multiple nodules and cavities
predominantly in the right lung (Fig 1, top, A). Chest CT scans
disclosed that cavities and nodules were associated with bronchiectasis (Fig 1, bottom, B).
Video-assisted thoracoscopic lung biopsy was performed as a
diagnostic procedure after obtaining informed consent. Histologic examination revealed necrotizing granulomas and vasculitis associated with prominent eosinophilic infiltration (Fig 2,
top left, A, top right, B, and bottom left, C). These findings
were compatible with the histologic features of CSS in the
lung; however, clusters of Gram-positive, coryneform rods
were observed in the alveolar spaces (Fig 2, bottom right, D).
Gram-positive, short coryneform bacteria were isolated from
lung tissue. The Elek test and Vero cell assay, which are
standard microbiology tests, and sequencing of the tox gene
showed clearly that this strain of C ulcerans produced diphtheria toxin identical to that of Corynebacterium diphtheriae.4,5 The isolate was susceptible to clarithromycin, benzylpenicillin, and levofloxacin. Clarithromycin, 400 mg/d, was
introduced and maintained. One week later, 1 million IU/d of
benzylpenicillin was additionally administered IM for 2 weeks.
Thereafter, 400 mg/d of levofloxacin was administered for 6
months. Without the use of immunosuppressant therapy, his
symptoms gradually improved, with chest images demonstrating dramatic improvement in the lung nodules. The patient
has been in good health during the 8-month follow-up period.
Discussion
Only two cases of lung disease caused by C ulcerans
have been reported in the literature.2,3 As in the
previous cases, necrotizing granulomas were observed
in the lung. However, the current case had necrotizing
angiitis with marked eosinophilic infiltration in the
lung, which has not previously been reported. The
histologic features of the lung in this case resemble
CSS. However, the current case did not meet the
criteria of CSS, as there was no history of bronchial
asthma.6 Gram-positive, coryneform rods were identified in the alveolar spaces, and C ulcerans was isolated
from tissue culture of the inflamed lung. The patient
was successfully treated only with antibiotics, without
any immunosuppressive agent, although CSS-generated
inflammation usually requires intervention with highdose corticosteroid, sometimes in combination with
cyclophosphamide. Hence, we concluded that the CSS-
Figure 2. Lung biopsy specimen obtained by video-assisted thoracoscopic lung biopsy. Top left, A:
Nodules show central necrosis with eosinophil infiltration. Epithelioid granulomas were observed
around the area of necrosis (arrowheads) [hematoxylin-eosin, original ⫻ 100]. Top right, B: Vasculitis
with eosinophil infiltration (arrows) [hematoxylin-eosin, original ⫻ 400]. Bottom left, C: Corresponding
elastica van Gieson stain of top right, B shows partial destruction of vessel wall (arrows) [original ⫻ 400]. Bottom right, D: Clusters of Gram-positive, coryneform rods in the alveolar spaces (arrow)
[Gram stain, original ⫻ 1,000].
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Selected Reports
like lung inflammation in this case was induced by C
ulcerans infection. Interestingly, bronchiectasis was observed on chest image. We assume that this has been
newly caused by C ulcerans infection, not been predisposed to the infection, because this has been gradually
improved with antibiotics and reversible.
C ulcerans infection in human occurs after consuming unpasteurized milk or coming in contact with dairy
animals. Person-to-person transmission of C ulcerans is
rare.7 Our patient had no direct contact with dairy
livestock, or unpasteurized dairy products, and no
person around the patient complained same symptoms.
Recently, C ulcerans producing diphtheria toxin was
isolated from nasal discharge of domestic cats in the
United Kingdom, and the isolates were found to exhibit
the predominant ribotypes observed among human
clinical isolates.7 Hatanaka et al8 reported a case of
diphtheria-like illness in a Japanese woman who had
been scratched by a cat with a runny nose. Our patient
kept 12 cats in his home, with several of them exhibiting
rhinorrhea and sneezing prior to onset of his illness.
These cats might have been carriers of C ulcerans and
possibly transmitted the bacterium to him.
We report the first case of C ulcerans infection of the
lung mimicking CSS. This bacterium should be taken into
consideration when encountering the histologic features of
CSS in the lung, and effective antimicrobial chemotherapy
should be planned accordingly.
ACKNOWLEDGMENT: The authors are grateful to Dr. Masanori Kitaichi, Kinki-chuo Chest Medical Center, for his comments on histopathology, and to Dr. Takako Komiya, Dr. Masaaki
Iwaki, Dr. Motohide Takahashi, and Dr. Yoshichika Arakawa,
National Institute of Infectious Disease, for their help in the
identification of C ulcerans. Thanks are also due to Dr. Takuya
Ueno, Ms. Mariko Ono, and Ms. Kaori Hirano for their technical
assistance.
References
1 Gubler JG, Wust J, Krech T, et al. Classical pseudomembranous diphtheria caused by Corynebacterium ulcerans.
Schweiz Med Wochenschr 1990; 120:1812–1816
2 Siegel SM, Haile CA. Corynebacterium ulcerans pneumonia
[letter]. South Med J 1985; 78:1267
3 Dessau RB, Brandt-Christensen M, Jensen OJ, et al. Pulmonary nodules due to Corynebacterium ulcerans. Eur Respir J
1995; 8:651– 653
4 Reinhardt DJ, Lee A, Popovic T. Antitoxin-in-membrane and
antitoxin-in well assays for detection of toxigenic Corynebacterium ulcerans. J Clin Microbiol 1998; 36:207–210
5 Miyamura K, Nishio S, Ito A, et al. Micro cell culture method
for detection of diphtheria toxin and antitoxin titers by VERO
cells. J Biol Stand 1974; 2:189 –201
6 North I, Strek ME, Leff AR. Churg-Strauss syndrome.
Lancet 2003; 361:587–594
7 De Zoysa A, Hawkey PM, Engler K, et al. Characterization of
toxigenic Corynebacterium ulcerans strains isolated from
humans and domestic cats in the United Kingdom. J Clin
Microbiol 2005; 43:4377– 4381
8 Hatanaka A, Tsunoda A, Okamoto M, et al. Corynebacterium
ulcerans diphtheria in Japan. Emerg Infect Dis 2003; 9:752–
753
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Adenocarcinoma of the Lung
Presenting as a Mycetoma
With an Air Crescent Sign*
Lan-Fu Wang, MD; Hsi Chu, MD;
Yuh-Min Chen, MD, PhD, FCCP; and
Reury-Perng Perng, MD, PhD, FCCP
An 89-year-old man was admitted to the hospital due to
intermittent anterior chest wall pain for > 1 month. A
chest radiograph obtained on November 9, 2004, demonstrated a mass with an irregular border, inside a thinwalled cavity, located in the superior segment of the left
lower lobe. A chest CT scan revealed an irregular thinwalled cavity, 5.9 ⴛ 5.4 ⴛ 4 cm in size, with an aircrescent sign in the superior segment of the left lower
lobe, and an intracavitary fungus ball-like mass. A bronchoscopic examination was performed, revealing only
external compression of the left lower lobe bronchial
lumen. Cultures from both the brushing cytology and
brushing fungus specimens were negative. Since the
patient was a heavy smoker and the chest radiograph
obtained 23 months before had revealed no active pulmonary lesion, neoplastic growth was still highly suspected. Thus, an 18F-fluoro-2-deoxyglucose positron
emission tomography study was performed on November
25, and a mass with a slightly increased standard uptake
value (3.17; cutoff value, 2.5) was found. He received a
left lower lobe lobectomy on December 23, and a tumor
with many septum-like structures connecting the surrounding pulmonary parenchymal tissue was found in the
superior segment of the left lower lobe. The final pathologic diagnosis was adenocarcinoma of the lung
(pT2N0M0). Thus, even though the chest radiograph and
chest CT scan showed a typical air-crescent sign (ie, mass
inside a cavity) favoring a mycetoma, the physician should
still keep in mind that lung cancer may also unusually
present in this way.
(CHEST 2007; 131:1239 –1242)
Key words: air crescent sign; lung cancer; mycetoma
Abbreviations: FDG ⫽ 18F-fluoro-2-deoxyglucose; PET ⫽ positron emission tomography; SUV ⫽ standard uptake value;
TB ⫽ tuberculosis
*From the Chest Department, Taipei Veterans General Hospital,
Taipei, Taiwan, Republic of China.
The authors have reported to the ACCP that no significant
conflicts of interest exist with any companies/organizations whose
products or services may be discussed in this article.
Manuscript received June 21, 2006; revision accepted August 2,
2006.
Reproduction of this article is prohibited without written permission
from the American College of Chest Physicians (www.chestjournal.
org/misc/reprints.shtml).
Correspondence to: Yuh-Min Chen, MD, PhD, FCCP, Chest
Department, Taipei Veterans General Hospital, 201 Section 2,
Shih-Pai Rd, Taipei 112, Taiwan, Republic of China; e-mail:
[email protected]
DOI: 10.1378/chest.06-1551
CHEST / 131 / 4 / APRIL, 2007
1239
n 89-year-old man was admitted to the hospital on
A November
9, 2004, due to intermittent anterior
chest wall pain for ⬎ 1 month. No fever, cough, or body
weight loss was noted. His medical history included
ischemic heart disease, which was under regular medical control. He had smoked 10 cigarettes daily for ⬎ 40
years. A physical examination revealed no remarkable
findings. The chest radiograph obtained on hospital
admission revealed a thin-walled cavity and a mass with
an irregular border inside the cavity, which was located
in the superior segment of the left lower lobe. A chest
CT scan revealed a thin-walled cavity with irregular
outer border, 5.9 ⫻ 5.4 ⫻ 4 cm in size, with an air-crescent
sign, in the superior segment of the left lower lobe, and an
intracavitary fungus ball-like mass (Fig 1). The thickness of
this thin, wall-like structure was approximately 2 to 5 mm,
with a less clear outside border infiltrating into the pulmonary parenchyma. Bronchoscopic examination disclosed a
narrowing of the left lower lobe bronchial lumen, caused by
external compression. Brushing cytology, acid-fast bacilli
smear and culture, and fungus culture showed negative
results. Since the patient was a smoker and the chest
radiograph obtained in December 2003 had shown no
active pulmonary lesion, pulmonary neoplastic growth was
still highly suspected. Thus, an 18F-fluoro-2-deoxyglucose
(FDG) positron emission tomography (PET) scan was
arranged, and the resulting images showed a homogenous
mass 6.1 ⫻ 6 ⫻ 6.1 cm in the left lower lobe (Fig 2). The
standard uptake value (SUV) of the FDG uptake was 3.17
for this mass. Since a mycetoma would not be expected to
have any uptake on PET scanning, because it does not
have a blood supply, any uptake at all within the central
solid lesion would rule out the presence of a mycetoma.
Thus, the PET scan results excluded the possibility of
mycetoma in our patient. He then underwent a left lower
lobe lobectomy. The operative findings were a mass with
many septum-like structures connecting the surrounding
pulmonary parenchymal tissue in the superior segment of
the left lower lobe (Fig 3), and the final pathologic
diagnosis was adenocarcinoma of the lung (pT2N0M0)
[Fig 4].
Discussion
Lung cancer is the leading cause of cancer death in the
world. The common radiologic presentations of lung cancer
Figure 1. Chest CT scan shows one 5.9 ⫻ 5.4 ⫻ 4 cm cavitary
lesion with an irregular thin wall, and one 4.6 ⫻ 3.1 ⫻ 3 cm
lobulated mass in the center (with an air-crescent sign), in the
superior segment of the left lower lobe. Top, A: coronal section of
the three-dimensional reconstruction. Bottom, B: cross section of
the lung window view. The thickness of this irregular wall was
about 2 to 5 mm, with a less clear outside border infiltrating into
the pulmonary parenchyma.
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Figure 2. FDG-PET scan shows an obvious and homogeneous
mass with an SUV of 3.17, located over the left lower lobe
(arrow).
Selected Reports
Figure 3. A gray-white firm tumor, 4.2 ⫻ 3.5 ⫻ 2.2 cm in size,
with some septum-like structures in the peripheral region, was
noted inside the left lower lobe (17 ⫻ 7.2 ⫻ 4.8 cm).
patients include a solitary pulmonary nodule, lung
consolidation, collapse, pleural effusion, and/or mediastinal widening. Lung cancer presenting with an aircrescent sign or as a mycetoma-like lesion is very rare.
This air-crescent sign seen (ball-in-hole) in the chest
radiograph or chest CT scan is most often associated
with an inflammatory process such as mycetoma, a
hydatid cyst, lung abscess, or pulmonary tuberculosis
(TB).1 Mycetoma frequently occurs in preexisting cavitary lesions of the lung formed by a previous pulmonary
tuberculous infection. In addition to combining with
Figure 4. Microscopic finding of sections of the left lower lobe
tumor shows well-differentiated adenocarcinoma with a papillary
growth pattern (hematoxylin-eosin, original ⫻100).
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mycetoma, pulmonary TB can also be found together
with lung cancer, simultaneously or sequentially.2 However, in our previous large-scale retrospective analysis2
of 31 patients with pulmonary TB and lung cancer from
1988 to 1994, including 3,928 lung cancer patient
profiles, we never found a cavitary TB lesion with
mycetoma inside the cavity, combined with another
lung cancer lesion, in the same patient. Mycetoma was
more frequently suspected or misdiagnosed as lung
cancer,3 and only rarely did mycetoma arise from a
cavitary lesion within lung cancer.4
Although lung cancer can occur after previous pulmonary injury, such as a scar cancer growing from a
fibrotic or granuloma lesion due to previous pulmonary
TB infection, the majority of lung cancers are due to
smoking. Even in those lung cancers that derive from
previous pulmonary injury, the majority of lesions are
located at or derived from a fibrotic or granuloma
lesion, instead of a TB cavity. When lung cancer does
occur in a previously existing cavity, one will find, in
addition to typical fibronodular lesions distributed in
the lung, an irregular nodular lesion, which progressively enlarges, inside a chronic preexisting TB cavity.
In contrast, no evidence of any pulmonary TB lesions
was found in the image study of our case; thus, pulmonary TB with a TB cavity and tumor growth inside the
cavity was much less likely to have been our clinical
impression before the patient received surgical intervention. The reason why our patient had a ball-in-hole or
an air-crescent sign appearance in the chest image was
that the tumor infiltrated with a paracicatrical effect
around the peripheral pulmonary parenchyma, thus inducing compensatory emphysematous or cystic change
between the tumor-infiltrating bands. This was documented by both the surgical gross specimens and pathologic findings.
In addition, in patients with a pulmonary mycetoma
(fungal ball), the radiographic feature is usually evident
as an upper lobe cavitary lesion with an intracavitary
mobile mass and an air-crescent sign on the periphery.5,6 A change in the position of the mycetoma
occurring when the patient changes his position is a
valuable radiologic sign for the diagnosis of mycetoma.5,7 Thus, the classic CT scan workup of a mycetoma
would include both supine and prone scanning studies
to demonstrate whether the central mass is free or
attached to the cystic wall.
The reason we performed a PET scan to rule out a
malignancy is that the patient was a heavy smoker and
his chest radiograph examination from 23 months before had negative findings, implying a greater possibility
of cancer formation. PET scanning is a sensitive imaging method for both inflammatory processes and malignancies.8 Many inflammatory lesions have a maximal
SUV of ⬍ 2.5, and the specificity of this cutoff SUV was
approximately 70 to 90% in one study.9 In addition to
the SUV data, PET imaging itself is another important
differentiating clue, as a fungus ball will show a cavitary
lesion with an increased SUV at the wall of the cavity,
CHEST / 131 / 4 / APRIL, 2007
1241
with no radioactivity inside the cavity, since mycetoma
does not have a blood supply. Thus, any uptake at all
within the central solid lesion would rule out the
presence of a mycetoma (Fig 5). Topologically, the
hyphae are still outside the patient’s body, so the
mycetoma is more of a colonization than an infection,
similar to the microbes found on the skin surface; this
also explains why there would be no uptake at all within
the solid portion of a mycetoma, but only around the
edges of the host cavity, as shown in Figure 5. Thus, a
mycetoma will have increased uptake in the wall of the
cavity on PET scans, but not in the fungal ball. In
contrast, in patients with lung cancer a mass with
increased SUV (Fig 2) is revealed. In patients with lung
cancer, PET scanning is usually incorporated into the
conventional staging algorithms for a patient with nonsmall cell lung cancer10 and is also able to evaluate the
primary lesion.9
In conclusion, the physician should keep in mind that
lung cancer may have an air-crescent sign or mycetomalike appearance in the roentgenographic images. In
addition to clinical history and chest imaging studies
obtained with the patient in both the supine and prone
positions, PET scan images can help in the differential
diagnosis.
References
1 Abramson S. The air crescent sign. Radiology 2001; 218:230 –
232
2 Chen YM, Lee PY, Chao JY, et al. Shortened survival of lung
cancer patients with active pulmonary tuberculous infection.
Jpn J Clin Oncol 1996; 26:322–327
3 Torpoco JO, Yousuffuddin M, Pate JW. Aspergilloma within
a malignant pulmonary cavity. Chest 1976; 69:561–563
4 Osinowo O, Softah AL, Zahrani K, et al. Pulmonary aspergilloma simulating bronchogenic carcinoma. Indian J Chest Dis
Allied Sci 2003; 45:59 – 62
5 Shuji B, Jiro F, Yoko F, et al. Cavitary lung cancer with an
aspergilloma-like shadow. Lung Cancer 1999; 26:195–198
6 Ayman OS, Pranatharthi HC. The clinical spectrum of pulmonary aspergillosis. Chest 2002; 121:1988 –1999
7 Roberts CM, Citron KM, Strickland B. Intrathoracic aspergilloma: role of CT in diagnosis and treatment. Radiology 1987;
165:123–128
8 Reichenberger F, Habicht JM, Gratwohl A, et al. Diagnosis
and treatment of invasive pulmonary aspergillosis in neutropenic patients. Eur Respir J 2002; 19:743–755
9 Ho CL. Clinical PET imaging: an Asian perspective. Ann
Acad Med Singapore 2004; 33:155–165
10 Victor K, Rodney JH, Michael PM, et al. Clinical impact of
F-fluorodeoxyglucose positron emission tomography in patients with non-small cell lung cancer: a prospective study.
J Clin Oncol 2001; 19:111–118
Hemoglobin Bassett Produces
Low Pulse Oximeter and Cooximeter Readings*
Arvind Das, MD; Sameer Sinha; and James D. Hoyer, MD
Figure 5. Chest CT scan (top, A) and PET scan image
(bottom, B) of a 74-year-old man with a pulmonary mycetoma
of the right upper lobe. The CT scan (top, A) shows a mass
inside a thin-walled cavity located in the right upper lobe
(arrow). A PET scan (bottom, B) from November 16, 2000, shows
a mass in the lung with an absence of radioactivity in the central
portion and a slightly increased FDG uptake (SUV, 1.63 vs 0.45 in
a contralateral normal lung) at the periphery of the lesion, which is
compatible with mycetoma of the lung rather than a malignancy
(arrow).
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Variant hemoglobins can have altered oxygen affinity and can produce changes in oximeter readings.
We present a case of hemoglobin Bassett, a possible
cause of low pulse oximeter and co-oximeter readings in a 63-year-old woman.
(CHEST 2007; 131:1242–1244)
Key words: hemoglobin Bassett; pulse oximetry; variant hemoglobin
Abbreviations: P50 ⫽ partial pressure of oxygen required for 50%
saturation of hemoglobin; Spo2 ⫽ oxygen saturation using pulse oximetry
Selected Reports
Case Report
woman went for an elective hernia repair that
A 63-year-old
cancelled due to low oxygen saturation using pulse oximetry
(Spo2) readings. Her only relevant symptom was mild dyspnea on
exertion. She had a history of acute pancreatitis 15 years earlier.
During much of that period, she had been on a respirator, and
had difficulty weaning from it despite a tracheostomy. Once off
the respirator, she had gradually improved to the point of
normality, and the tracheostomy stoma closed spontaneously. She
had 15-pack-year smoking history, and she quit smoking 20 years
ago. No one else in her family had any blood or respiratory
disorders.
The patient was moderately obese, had normal vital signs,
and had a normal physical examination except for the inguinal
hernia and mild bilateral lymphedema of legs, but Spo2 was
85% at rest. Pulmonary function tests showed a mild restrictive pattern with a borderline normal diffusing capacity, and
chest radiographic findings were normal. The serum metabolic
panel was normal, including the levels of phosphorus and
thyroid-stimulating hormone. The CBC was normal, with a
hemoglobin level of 14.4 g/dL. A simple pulmonary stress test
was performed on a stationary bike. The patient stopped
exercising 6 min into the test (at 75 W) due to general fatigue,
without dyspnea. Her Spo2 dropped to 81% within the first
minute of exercise and remained at this level throughout the
exercise. After 3 min of rest, her Spo2 increased back to 85%.
She did not have exercise-induced bronchospasm, or ECG
changes. Arterial blood gas measurement (ABL 700 series;
Radiometer; Copenhagen, Denmark) showed a pH 7.42;
Paco2, 31 mm Hg; Pao2, 85mm Hg; and arterial oxygen
saturation of 86% at rest on room air. Co-oximetry showed no
methemoglobinemia, and both fetal and carboxy hemoglobin
levels of ⬍ 1%.
Hemoglobin analysis was performed at Mayo Clinic utilizing
alkaline and acid electrophoresis, isoelectric focusing, globin
chain electrophoresis, and cation-exchange high-performance
liquid chromatography. These methods identified a hemoglobin
variant that accounted for 16.1% of the total hemoglobin. The
electrophoretic characteristics were consistent with hemoglobin
Bassett, and DNA sequencing of the ␣-globin genes confirmed a
GAC to GCC (Asp to Ala) substitution at position 94.
Using a sample of the patients’ whole blood in the Hemox
Analyzer (TCS Scientific Corporation; Southampton, PA), a
hemoglobin-oxygen equilibrium curve was plotted that was normal, with a partial pressure of oxygen required for 50% saturation
of the hemoglobin (P50) of 28 mm Hg (Fig 1).
*From the Department of Medicine (Dr. Das), UMDNJ-Robert
Wood Johnson Medical School, New Brunswick, NJ; University
of Connecticut (Mr. Sinha), Storrs, CT; and Department of
Laboratory Medicine and Pathology (Dr. Hoyer), Mayo Clinic,
Rochester, MN.
The authors have no conflicts of interest to disclose.
Manuscript received June 13, 2006; revision accepted September
6, 2006.
Reproduction of this article is prohibited without written permission
from the American College of Chest Physicians (www.chestjournal.
org/misc/reprints.shtml).
Correspondence to: Arvind Das, MD, Clinical Associate Professor,
Department of Medicine, UMDNJ-Robert Wood Johnson Medical
School, 81 Veronica Ave, Suite 201, Somerset, NJ 08873; e-mail:
[email protected]
DOI: 10.1378/chest.06-1310
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Figure 1. Cation-exchange high-performance liquid chromatography for hemoglobin Bassett. The abnormal hemoglobin elutes
as a distinct peak at 4.62 min.
Discussion
Low Spo2 is generally due to a low Pao2. However, low
Spo2 can also be caused by mechanical and other biological factors (Table 1).
Once these causes have been excluded, a rightward shifted
hemoglobin-oxygen equilibrium curve, as reflected by a
higher P50, becomes the most plausible explanation. Causes
of a right-shifted hemoglobin-oxygen curve include hypercapnea, chronic acidosis, hypophosphatemia, hypothyroidism, infusion of stored blood, reduced levels of 2,3-diphosphoglycerate, fever, and certain variant hemoglobins.
Hemoglobin Bassett is known to have a substitution of
Asp3Ala at position 94 of the ␣1 globin chain. This happens to
be a ␣1␤2 contact region and is crucial for the normal oxygenation and deoxygenating of the hemoglobin. But ␣1 globin
forms only 30% of the total hemoglobin in humans. Therefore,
a mutation in just one of the ␣1 globin genes would alter only
Table 1—Causes of Falsely Low SpO2 Readings
Hypoperfusion of the probe site from hypotension, cold, fear, and
medications
Dark skin pigmentation, painted nails, and tissue edema at the
probe site
IV dyes
Methylene blue in blood
Body movement
Pulsatile venous system, eg, during cardiopulmonary resuscitation
and from tricuspid regurgitation
Interference from radiated bright light, including fluorescent and
infrared lights
Methemoglobinemia
M hemoglobins
CHEST / 131 / 4 / APRIL, 2007
1243
15% of the total hemoglobin. We believe this to be the case in
our subject, in whom hemoglobin Bassett constituted only
16.1% of the total hemoglobin, and therefore had no significant
effect on the overall P50. The clinical manifestations of variant
hemoglobins can vary from a complete lack of symptoms to mild
anemia, polycythemia, dyspnea, to respiratory distress and cyanosis starting in early life.1–4
Supplemental oxygen can be utilized to maximize the
Pao2, hence the arterial oxygen saturation and the oxygencarrying capacity of the subject’s blood. Additional benefit
can be obtained by optimizing the subject’s hemoglobin
level, and by transfusion of normal blood.
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References
1 Edmonds L, Fairbanks VF, McCormick DJ, et al. Hemoglobin Bassett, alpha 94 (G1) Asp-Ala: a new low O2-affinity
variant associated with chronic anemia [abstract]. Blood,
Abstract issue for American Society Hematology, 1998; 97
2 Middleton PM, Henry JA. Pulse oximetry: evolution and
directions. Int J Clin Pract 2000; 54:438 – 444
3 Sinex JE. Pulse oximetry: principles and limitations. Am J
Emerg Med 1999; 17:59 – 66
4 Abdulmalik O, Safo M, Lerner N, et al. Characterization of
hemoglobin Bassett (␣94Asp3 Ala), a variant with very low
oxygen affinity. Am J Hematol 2004; 77:268 –276
Selected Reports