Feline Lymphoma.

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Feline Lymphoma.
COMPANION ANIMAL PR ACTICE
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Alison Hayes
graduated from
Glasgow in 1991
and spent five years
in mixed and small
animal practice in
north-west England.
She subsequently
undertook a
three-year Blue
Cross residency in
oncology at the
Animal Health Trust
in Newmarket,
where she is now a
clinical oncologist.
She holds the
RCVS certificate in
veterinary radiology
and an MSc
in clinical oncology
from the University
of Birmingham
medical school.
In Practice (2006)
28, 578-585
Four-year-old female domestic longhaired
cat, which presented with signs of upper
respiratory stridor and was FeLV-negative.
Third eyelid protrusion and reduced
retropulsion were noted, which were more
marked on the right side. Nasal biopsy
confirmed lymphoma and, after complete
staging, chemotherapy was commenced
with radiation therapy on relapse.
Generalised lymphadenopathy is rarely
a feature of lymphoma in cats
Feline lymphoma
2. Specific disease presentations
ALISON HAYES
THIS article, the second of two on feline lymphoma, discusses how the disease can present to the
veterinarian. Lymphoma is a differential diagnosis for a variety of clinical presentations in cats and can
occur in, or spread to, any anatomical site that contains lymphoid tissue. A regionally localised disease
must be assumed to have a systemic component unless proved otherwise. Thus, ascribing a disease to a
particular anatomical form (ie, mediastinal, alimentary or multicentric) can be difficult and may have led
to inaccuracies in reporting of the disease in the literature. In addition to these commonly recognised
forms, cutaneous, ocular, central nervous system, tracheal, renal, nasal and pulmonary forms are also
recognised. These various anatomical presentations of feline lymphoma may come to be regarded as
specific disease entities in their own right as more is learnt about the pathogenesis and biology of feline
lymphoid neoplasias, but are currently best considered as manifestations of a disease continuum. Rather
than struggling to ascribe an individual case to a particular anatomical form, the clinician should be aware
that the main aim of staging is simply to document all areas of involvement. Initial clinical investigations
will pertain to the organ system recognised in the presentation of disease, but full staging is always
required and should include diagnostic investigation of the whole patient wherever possible. This was
discussed further in Part 1, published in the last issue, which reviewed the principles of diagnosis and
management in feline lymphoma cases (In Practice, October 2006, volume 28, pp 516-524).
MULTICENTRIC LYMPHOMA
The term multicentric lymphoma is not synonymous with
multiple lymph node involvement. Although cats are
often described as having multicentric lymphoma, where
multiple organ systems are involved, this rarely includes
the generalised lymphadenopathy that is often seen in
dogs. This category of lymphoma usually includes cats
with liver, spleen or peripheral/intra-abdominal lymph
node involvement.
Clinical signs range from vague malaise, weight
loss or anorexia to more acute signs of liver failure.
Radiography and ultrasound examination of the abdomen
may indicate changes in the size, shape and echotexture
of the parenchymal organs, thus prompting needle aspirates in the first instance. It is worth remembering that
liver infiltration and/or elevated biochemical parameters
do not equate to liver failure and changes may be reversible with appropriate treatment. Compromised liver
function will require reductions in cytotoxic drug dosages and careful monitoring for signs of toxicity.
If generalised lymphadenopathy occurs in cats and
lymphoma is suspected, definitive histology is required
to avoid misdiagnosis of healthy, younger cats with non578
specific immune stimulation. Two studies have alluded
to this: in the first, lymphadenopathy was reported to
regress over time in a group of younger cats diagnosed
with lymphoma and presenting with generalised lymphadenopathy (Mooney and others 1987b) and, in the
Submandibular lymphadenopathy in a domestic
shorthaired cat of unknown age. Multicentric lymphomas
such as this rarely manifest as generalised peripheral
lymphadenopathy, which is common in dogs. In this cat,
there was marked, localised, unilateral enlargement of
the submandibular node (arrow). Picture, Lorraine Fleming
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second, peripheral lymph node enlargement in 14 cats
led to lymphoma in only one cat, with 13 cats undergoing spontaneous lymph node regression (Moore and others 1986). In the latter study, six out of nine cats tested
had feline leukaemia virus (FeLV) antigen detected in
the blood and had similar histology findings to kittens
developing lymphadenopathy following experimental
FeLV infection. In addition to histology, immunohistochemistry and FeLV antigen detection may be helpful in
determining a definitive diagnosis. If there is any ambiguity, clinical monitoring and re-biopsy is advocated
before making treatment decisions.
MEDIASTINAL LYMPHOMA
Mediastinal disease is a common presentation of lymphoma. Cats are often dyspnoeic, although sometimes
this is not recognised by owners. Radiographic changes
include an anterior thoracic mass effect with or without a pleural effusion. The thymus, mediastinal, presternal and other intrathoracic lymph nodes may all be
affected. Lymphadenopathy may be appreciated in the
thoracic inlet and lower cervical area. Displacement of
the apex beat and dulled lung sounds will be heard on
clinical examination. Regurgitation and dysphagia may
also be reported by owners. Cytology of pleural fluid
is usually supportive of the diagnosis, although histology is advisable wherever possible, especially in older
cats that are FeLV-negative, in which the disease must
be differentiated from thymoma, which may be treated
surgically.
Ultrasound examination of the thorax facilitates
guided fine needle aspiration or core biopsy of abnormal
tissue. The presence of pleural fluid can aid ultrasonography, but due care is needed and thoracocentesis may
be required for initial stabilisation before further investigation can take place. In cats, the right second to third
or third to fourth intercostal space is a commonly used
site for this. Care should be taken to avoid the intercostal
vessels along the caudal aspect of the rib, while directing
the needle along the thoracic wall to avoid lung trauma.
A butterfly catheter or short over-the-needle catheter
can be used, with or without extension tubing, and
attached to a three-way tap and syringe for short-term
drainage. The first fluid that is withdrawn should be
placed into EDTA and plain tubes for cellular and biochemical analysis.
The mainstay of treatment for mediastinal lymphoma
is cytotoxic chemotherapy, although low-dose radiation
therapy to consolidate treatment can lead to durable remissions (Elmsie and others 1991). Young, FeLV-negative,
Siamese cats may be overrepresented, but can respond
well to chemotherapy – often achieving complete and
durable remissions, allowing treatment to be stopped.
ALIMENTARY LYMPHOMA
Alimentary (or gastrointestinal) lymphoma is frequently
seen in cats. The small and large intestines, oral cavity,
oesophagus, stomach, mesenteric nodes, pancreas and
liver can all be involved. Presenting signs include weight
loss, anorexia, lethargy and diarrhoea. Vomiting is not
a consistent feature of the disease in cats. Intestinal
involvement is generally regarded as a diffuse bowel
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Right lateral recumbent
(above) and dorsoventral
(left) projections of
the thorax showing a
mediastinal lymphoma
in a 10-year-old domestic
shorthaired cat. The
thoracic air space is
almost obliterated by
a homogeneous soft
tissue opacity which
obscures the cardiac
silhouette and displaces
the trachea dorsally and
to the right (arrows). Only
the dorsocaudal part of
the right lung remains
aerated. The disease must
be distinguished from
thymoma, which may
be treated surgically.
Ultrasound-guided
Tru-cut biopsy can provide
a definitive diagnosis
disease, but may initially manifest as a solitary, focal
mass detectable on abdominal palpation. Alternatively,
abdominal palpation can reveal diffuse, cord-like bowel
thickening. Abdominal ultrasonography is essential for
diagnosis, staging and monitoring, and facilitates guided
core and needle biopsy. Bowel thickening, loss of motility and layering, hypoechogenicity and lymphadenopathy
are characteristic changes seen on ultrasound examination (Penninck and others 1994).
When the disease presents as diffuse gastrointestinal
changes, diagnosis may be achieved by ultrasound-guided
needle or endoscopic grab biopsies prior to commencing
chemotherapy. For more solitary masses, fine needle aspiration or needle-core techniques can be used. A surgical
approach is required if definitive diagnosis is not achieved
with non-invasive techniques such as Tru-cut style biopsies or when there is an immediate need to relieve bowel
obstruction or intussusception. Superficial grab biopsies
obtained endoscopically should be interpreted with caution, as these may underdiagnose lymphoma involving the
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deeper layers and overestimate the importance of inflammatory bowel changes seen more superficially.
Treatment can be surgical, medical or a combination
of the two. Limitations apply to each form of treatment.
Chemotherapy can be used as a first-line treatment if a
definitive diagnosis has already been achieved by noninvasive means. However, large, focal mass lesions
treated with chemotherapy can result in a full thickness defect once malignant lymphoid tissue is lost and
close monitoring is required during the initial induction
phase. Surgical resection of large areas of bowel does
not appear to prolong survival compared with cats treated medically. Chemotherapy is advocated after recovery
from surgical diagnostic and therapeutic procedures.
Cats with low-grade gastrointestinal lymphoma have
been shown to respond well to a combination of prednisolone (10 mg per cat per day) and chlorambucil (15
mg/m2 daily for four days, repeated every three weeks),
achieving a median survival time of 22·8 months for the
67 per cent of animals that achieved complete remission
(Fondacaro and others 1999). In another study, which
did not differentiate the grade of disease, 71 per cent of
cats with gastrointestinal lymphoma achieved complete
remission with a median survival time of 259 days and
an overall median survival time for all cats of 201 days
following treatment with a doxorubicin-based, six-drug
protocol (Rassnick and others 1999). However, two other
Lymphoma or IBD?
If there is a relationship between inflammatory bowel disease and lymphoma,
it is a contentious one. The pathological classification of feline lymphocytic
enteric disease has not yet been fully elucidated. Researchers have found that
epitheliotropic intestinal lymphoma, characterised by infiltration of the superficial layers with small lymphocytes, can only be reliably differentiated from
inflammatory bowel disease by identifying clonality on immunohistochemistry
(Carreras and others 2003) and future molecular studies may aid further understanding. Currently, it is still unclear whether inflammatory bowel disease is a
reaction or a precursor to lymphoma. Although it is tempting to regard these
two diseases as a continuum of each other, this may prove to be inaccurate.
Cats that show a poor response to inflammatory bowel disease therapy should
be reviewed, and a diagnosis of lymphoma reinvestigated.
studies have reported outcomes suggesting that cats with
gastrointestinal lymphoma may respond less favourably
to combination protocols than cats with other forms of
the disease. Zwahlen and others (1998) reported that,
of 21 cats treated with a doxorubicin-based, six-drug
protocol, 38 per cent achieved complete remission with
a median survival time of 291 days, and an overall survival time of 280 days for all cats. In the second study,
Mahony and others (1995) reported that, of 27 cats treated with cyclophosphamide, vincristine and prednisolone
(COP), 33 per cent achieved complete remission, with a
median survival time of 213 days for those animals in
complete remission and an overall survival time of 50
days.
As with other forms of the disease, the best chemotherapy protocol for gastrointestinal lymphoma is probably
yet to be determined. However, from the limited studies
to date, it appears that COP alone is probably inadequate
for the management of gastrointestinal lymphoma.
RENAL LYMPHOMA
Renal lymphoma is the most common renal tumour in
cats and often presents with acute-onset renal insufficiency, anorexia, weight loss and polyuria/polydipsia.
Bilaterally enlarged, and sometimes irregular, kidneys
can be found on palpation of the abdomen and confirmed
radiographically. An apparent unilateral presentation can
be encountered, although the disease is considered to be
bilateral in all cases. Unsuspected renal involvement
can be discovered during ultrasound examination if loss
of corticomedullary definition is seen. This can be due
to cortical infiltration by neoplastic lymphocytes. The
diagnosis must be confirmed with fine needle aspiration or Tru-cut style biopsy. There may be an association
between renal and nasal lymphoma, and also between
renal and central nervous system lymphoma, but this is
still unproven.
Treatment for renal lymphoma is always drug-based
and can result in a rapid resolution of azotaemia, leaving relatively undamaged, functional kidneys. Surgical
removal of a kidney for diagnostic purposes should be
unnecessary and is not warranted from a therapeutic
Right lateral recumbent
projection of the abdomen
of a seven-year-old
domestic shorthaired cat
with renal lymphoma. There
is marked enlargement of
both kidneys (cranial and
caudal pole of each kidney
shown by arrows), which
has displaced the abdominal
contents caudoventrally.
These are typical signs of
this condition in cats. This
cat also had disseminated
signs of disease, suggested
by the pleural effusion
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Right lateral recumbent (above) and ventrodorsal (left)
projections of the abdomen of a nine-year-old domestic
shorthaired cat with renal lymphoma. Note the
asymmetry of the left and right renal silhouettes. The
left kidney is enlarged, with an irregular, globoid shape
and lies more ventrally than normal (white arrows).
The right kidney is also enlarged, but retains its normal
shape and position in the right dorsal abdomen (black
arrows). Renal involvement is often bilateral, but this
may not be clinically apparent, and enlargement may
not be symmetrical
perspective. Survival times can be prolonged for cats
with renal lymphoma; in one study involving 11 cats
with disease confined only to the kidneys and treated
with a multidrug protocol, the median survival time was
396 days (Mooney and others 1987a). The degree of azotaemia should not be regarded as a prognostic indicator
in cats with renal lymphoma. It is important to realise
that reported median survival times may be unrepresentative of renal lymphoma per se, due to the possible
link with central nervous system lymphoma and the
more guarded prognosis that this carries.
Supportive care is required in cases of renal lymphoma, especially in the early stages of diagnosis and treatment. Cytotoxic drug dose reductions may be necessary
in sick patients. Drug doses may be increased after the
initial azotaemia has resolved. Special care should be
Ultrasound image showing a normal feline kidney
(above left) Ultrasound image from a nine-year-old domestic shorthaired cat showing renal lymphoma in the left kidney prior to treatment. The kidney
is enlarged, measuring 50·91 mm along the long axis (normal range 37 to 44 mm). A hypoechoic rim surrounds the kidney, indicating subcapsular
fluid and cellular infiltration (white arrows). Poor corticomedullary definition and patchy areas of increased echogenicity give the cortex a mottled
appearance (black arrows). This loss of corticomedullary definition raises the suspicion of lymphoma and, although marked in this case, a more subtle
appearance without other renal changes should prompt the clinician to consider a diagnosis of lymphoma. (above right) Ultrasound image from the
same cat following chemotherapy with cyclophosphamide, vincristine and prednisolone. A marked reduction in renal size can be appreciated, with
the kidney now measuring about 41 mm in length. There is also a decrease in the amount of subcapsular fluid and almost normal corticomedullary
definition (arrows), although the mottled appearance of the cortex remains at this stage. Renal lymphoma can respond rapidly to chemotherapy
without major medical complications; such changes should not necessarily preclude an attempt at induction therapy
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Fine needle aspirate cytology from
a cat with renal lymphoma. Normal
lymphocytes have a nuclear diameter
approximately the same size as a red
blood cell (black arrow). The nucleated
lymphocytes (white arrows) have
enlarged nuclei, approximately two
to four times that of a red blood cell,
and scant cytoplasm. Magnification X40.
Picture, Mark Bestbier
Histology of a biopsy sample from a cat with renal
lymphoma showing an interstitial infiltrate of malignant
lymphocytes with a moderate variation in nuclear size
and shape. Loss of function can be reversible with
prompt treatment. Haematoxylin and eosin, magnification X10.
Picture, Mark Bestbier
taken with those drugs that require any degree of renal
excretion (eg, cyclophosphamide). If used, doxorubicin
should be administered with pre- and post-treatment
fluid therapy; extreme care should be taken with cats
with renal lymphoma, as this drug is nephrotoxic in this
species.
CENTRAL NERVOUS SYSTEM LYMPHOMA
Lymphoma can affect the brain or spinal cord either as a
main presenting sign or as a sign of progressive disease
in cats undergoing treatment. Most cats with central nervous system involvement will also have lymphoma in sites
other than the central nervous system. In the past, spinal
Bilaterally enlarged kidneys due to renal lymphoma seen
at postmortem examination. There are multifocal, nodular
lymphomatous infiltrates throughout the cortex, which is
swollen. Picture, Mark Bestbier
Transverse (left) and dorsal
(right) T2-weighted magnetic
resonance images of the
cervical spine of an 18-yearold domestic shorthaired cat
with a three-week history of
progressive tetraplegia. An
extradural lymphoma can
be seen as a roughly ovoid,
hyperintense, well-defined
mass within the vertebral
canal and there is marked
cord compression. A narrow,
hyperintense band between the
mass and the cord corresponds
to cerebrospinal fluid that is
located extradurally; this may
respond to chemotherapy as
drugs do not have to cross the
blood–brain barrier to reach
the target site
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lymphoma may have occurred more commonly, principally in FeLV-positive cats, but lymphoma in the brain
was reported less frequently and in older, FeLV-negative
cats. Clinical signs of brain involvement include irritability, seizures, circling, blindness, cranial nerve deficits and nystagmus. With spinal lymphoma, the onset of
signs can be acute or insidious, and focal hyperaesthesia
prior to clinical dysfunction has been reported. Paresis
and ataxia with a rapidly deteriorating clinical course are
common.
Definitive diagnosis can be difficult to achieve and
may account for the relative under-reporting of brain
involvement. Computed tomography or magnetic resonance imaging may detect a focal mass lesion, or a more
infiltrative or widespread pattern of change. An accurate diagnosis may come from sampling other distant
sites that are thought to be involved. Cerebrospinal fluid
analysis may demonstrate malignant cells, but negative
findings do not rule out lymphoma. The expected higher incidence of spinal lymphoma compared with lymphomas in the brain was not seen in a recent review of
cases at the Animal Health Trust. This may reflect the
changing face of feline lymphoma due to its FeLV/feline
immunodeficiency virus associations.
Drug-based protocols for brain lymphoma may
achieve less than expected for other forms of lymphoma, as most conventional cytotoxic drugs have minimal
access across the blood–brain barrier. Protocols containing cytosine arabinoside have been advocated in an
Transcorneal ultrasound scan of lymphoma in the
retrobulbar space of a nine-year-old domestic shorthaired
cat. An ill-defined, hypoechoic mass in the medial part of
the orbit causes indentation of the globe (white arrows).
There is also disruption of the hyperechoic line that
represents the bony medial wall of the orbit (black arrows).
Oral examination revealed a mass in the pterygopalatine
fossa, biopsy of which confirmed lymphoma
Ocular changes associated with lymphoma in a cat
of unknown age. There is localised thickening and
inflammation of the iris, most marked between
9 and 12 o’clock
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attempt to access affected areas. However, more success
is generally achieved with radiation therapy, usually in
conjunction with chemotherapy. Survival times of up to
seven months have been reported, but usually the prognosis is regarded as poor. Spinal lymphoma is mainly
extradural and thus should respond more favourably to
drug-based therapies, although parenchymal extension
can occur. Surgical decompression of the spine or adjuvant, low-dose radiation therapy may be considered on
an individual case basis. Survival is affected as much by
disease response to chemotherapy as by the timing of
decompression, which can cause permanent neurological
damage. Bone marrow analysis may yield a definitive
diagnosis without the need for spinal surgery.
OCULAR LYMPHOMA
Ocular lymphoma can be unilateral or bilateral, and can
precede the onset of systemic disease in many (but not
all) cats. Any part of the eye and retrobulbar space can
be affected. The uvea is most commonly affected and
can show either diffuse or nodular changes. When other,
systemic sites are thought to be involved, they should be
sampled to help yield a definitive diagnosis. If an exact
aetiology cannot be established, symptomatic treatment
for uveitis can be implemented with regular re-evaluation. If there is a gross tumour within the eye and other
sites are not involved, enucleation can be performed. In
Eight-year-old Persian cat with ocular changes associated
with lymphoma. Diffuse inflammation and thickening of
the iris was accompanied by miosis and keratic precipitates
on the corneal endothelium
Ocular changes associated with lymphoma in an
11-year-old domestic shorthaired cat. Diffuse inflammation
and thickening of the lateral part of the iris can be seen
together with distortion of the pupil and a cottage cheeselike deposit in the anterior chamber. Mild corneal oedema
can also be appreciated. This cat additionally had retinal
detachment and bilateral panuveitis
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experienced hands, aqueocentesis may yield a diagnosis
in some cases, thus permitting chemotherapy to be started without sacrificing the eye.
As with other forms of feline lymphoma, when ocular lymphoma is diagnosed, the possibility of systemic
disease should prompt the use of adjuvant chemotherapy,
although the clinician should be aware that some longterm survivors have been reported following enucleation
alone.
TRACHEAL LYMPHOMA
Tracheal lymphoma is an uncommon but well recognised form of feline lymphoma. Cats can present with
dyspnoea, wheezing, cyanosis, coughing and lethargy
(Brown and others 2003). Lesions can be visualised on
plain radiography and bronchoscopy will aid collection of material for cytology. Successful treatment with
chemotherapy has been reported, although radiation
therapy can be used as a primary treatment modality, or
as an adjunct to chemotherapy. As systemic disease can
be seen at presentation or relapse, it is safest to assume
that this form of lymphoma is part of a systemic disease and implement localised treatment as an adjunct to
systemic therapy.
Pre- (above) and post-radiotherapy (below) transverse postcontrast T1-weighted magnetic resonance images of a nasal
lymphoma in a 10-year-old domestic shorthaired cat at the
level of the caudal nasal cavity. Prior to treatment, a large
mass can be seen filling the left nasal cavity, but it does not
cross the nasal septum or invade the orbit (white arrow).
Fluid is trapped within the left frontal sinus (black arrow).
The post-treatment scan shows significant resolution; the
soft tissue mass is no longer apparent and the trapped fluid
has been allowed to drain. Radiotherapy can be useful for
localised disease, as a combined modality treatment or
rescue therapy
NASAL LYMPHOMA
Nasal lymphoma is also well recognised in cats.
Affected animals can present with upper respiratory
stridor, sneezing, nasal discharge, epiphora, and facial
pain or deformation. Deviation or poor retropulsion of
the globe should alert the clinician to the possibility of
orbital extensions. Although radiographic displacement
of midline structures, an increase in soft tissue opacity, loss of turbinate detail and bone invasion are all
more likely to be seen in cases of nasal neoplasia, these
changes are not specific for cancer versus rhinitis or for
lymphoma versus any other intranasal neoplasia. As with
other forms of lymphoma, careful staging is required.
See Part 1 for a discussion of biopsy techniques.
Dorsoventral intraoral projection of nasal lymphoma in
a nine-year-old domestic shorthaired cat. There is loss of
turbinate pattern unilaterally, an increase in soft tissue
opacity (arrow) and occlusion of the nostril. The cribriform
plate and medial orbital wall are ill-defined (not seen on
this radiograph). This cat’s orbital ultrasonogram (see page
583) suggested that the nasal lymphoma had extended
into the retrobulbar space. A definitive biopsy can often
be obtained without invasive procedures
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Treatment can involve either chemotherapy or radiation therapy, or a combination of the two modalities. In
the author’s experience, long-term survival is achievable with radiation therapy alone, and in the absence
of systemic involvement this is the preferred method
of treatment when available. This is supported by the
observations of other authors (Elmsie and others 1991).
However, systemic disease, even if absent at presentation, can manifest later in the course of disease and
ultimately chemotherapy may be required. Conversely,
relapsing nasal lymphoma treated by chemotherapy in
the first instance, either due to systemic involvement or
owner/vet preference, can be successfully rescued with
radiation therapy. When nasal disease extends to the
retrobulbar space, radiation of the globe may lead to
long-term complications necessitating enucleation. A
combined modality approach using chemotherapy to
downsize the tumour (neoadjuvant therapy) may allow
successful radiation therapy without irradiation of
the globe. Repeated sectional imaging to monitor the
response to drug-based treatment is essential in such
cases prior to commencing chemotherapy.
OTHER FORMS OF LYMPHOMA
Other forms of lymphoma can be diagnosed in cats,
either alone or as part of a multicentric presentation.
When lymphoma of the lung occurs, it tends to manifest as nodular lesions, which are uncommon in dogs.
Larnygeal lymphomas can cause respiratory stridor or
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dyspnoea. Cutaneous lymphomas can be solitary or diffuse, and composed of T or B cells. Solitary cutaneous
lymphomas can be cured surgically. In the case of multiple cutaneous lesions, or if surgical treatment is not indicated, treatment with conventional cytotoxic drugs can
be attempted. Plesiotherapy and external beam radiation
therapy may be useful as an adjunct to systemic treatment or as single modality therapy in areas that are
deemed to be non-surgical.
SUMMARY
Lymphoma can present in many different guises, and the
clinician should be alert to the possibility of this condition in any cat regardless of age, breed or viral status.
Treatment can be rewarding with rapid responses often
leading to a reversal of life-threatening situations within
hours or days of commencing appropriate therapy in the
practice setting. Histological diagnosis and full staging
are required to tailor treatment choices to the individual cat. All samples for diagnostic purposes should be
obtained before commencing therapy, including glucocorticoid treatment.
Acknowledgements
The images for this article were compiled with the help of the
Units of Comparative Ophthalmology and Diagnostic Imaging at
the Animal Health Trust, with particular thanks to Jane Samson,
Ruth Dennis and Fraser McConnell.
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Hodgkin’s-like lymphoma
A specific form of feline lymphoma, termed Hodgkin’s-like lymphoma, seems to
be emerging. As the term suggests, there are pathological and clinical similarities to this specific human form of lymphoma. In people, Hodgkin’s lymphoma
tends to affect contiguous lymph nodes in the neck and thorax, and the disease can be slow to progress. Treatment is often based on surgery and radiation, rather than systemic drug therapy, which is more commonly associated
with non-Hodgkin’s lymphoma. The neoplastic cells (Reed–Sternberg) are in the
minority and are found among non-neoplastic lymphocytes.
The feline form of the disease appears to affect older cats, which present
with unilateral and often focal cervical or mandibular lymphadenopathy. A
mixed population of lymphocytes is recognised with neoplastic cells seeming to
be in the minority (Walton and Hendrick 2001). A similar and possibly synonymous condition has been described by Day and others (1999) as a T cell rich B
cell lymphoma. Further work is required to categorise this disease more specifically and document the clinical outcome. In the author’s experience, neoadjuvant chemotherapy prior to localised lymph node excision for cervical lymphadenopathy has proved rewarding.
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(1987a) Renal lymphoma in cats: 28 cases (1977-1984). Journal
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MOONEY, S. C., PATNAIK, A. K., HAYES, A. A. & MacEWEN, E. G.
(1987b) Generalized lymphadenopathy resembling lymphoma
in cats: six cases (1972-1976). Journal of the American Veterinary
Medical Association 190, 897-900
MOORE, F. M., EMERSON, W. E., COTTER, S. M. & DELELLIS, R. A.
(1986) Distinctive peripheral lymph node hyperplasia of young
cats. Veterinary Pathology 23, 386-391
PENNINCK, D. G., MOORE, A. S., TIDWELL, A. S., MATZ,
M. E. & FREDEN, G. O. (1994) Ultrasonography of alimentary
lymphosarcoma in the cat. Veterinary Radiology & Ultrasound
35, 299-304
RASSNICK, K. M., MAULDIN, G. N., MOROFF, S. D., MAULDIN,
G. E., McENTEE, M. C. & MOONEY, S. C. (1999) Prognostic value
of argyrophilic nuclear organiser region (AgNOR) staining
in feline intestinal lymphoma. Journal of Veterinary Internal
Medicine 13, 187-190
WALTON, R. M. & HENDRICK, M. J. (2001) Feline Hodgkin’s-like
lymphoma: 20 cases (1992-1999). Veterinary Pathology 38,
504-511
ZWAHLEN, C. H., LUCROY, M. D., KRAEGEL, S. A. & MADEWELL,
B. R. (1998) Results of chemotherapy for cats with alimentary
malignant lymphoma: 21 cases (1993-1997). Journal of the
American Veterinary Medical Association 213, 1144-1149
Further reading
OGILVIE, G. K. & MOORE, A. S. (2001) Feline Oncology.
A Comprehensive Guide to Compassionate Care. Trenton,
New Jersey, Veterinary Learning Systems
VAIL, D. M. & THAMM, D. H. (2000) Hematopoietic tumours.
In Textbook of Veterinary Internal Medicine. Diseases of the
Dog and Cat, 6th edn. Eds S. J. Ettinger and E. C. Feldman.
Philadelphia, W. B. Saunders. pp 732-747
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CORRECTION
Feline lymphoma 1. Principles of diagnosis
and management (In Practice, October 2006,
volume 28, pp 516-524)
On page 522, the dose for vincristine in the bottom table
describing the MOPP protocol for rescue therapy should
have read 0·025 mg/kg and not as stated.
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Feline lymphoma 1. Principles of diagnosis
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