Renal Mass Pitfalls Case Studies

Renal Evaluation
Renal Mass
Pitfalls
Case Studies


JOHN P. MCGAHAN M.D.
PROFESSOR OF RADIOLOGY



UNIVERSITY OF CALIFORNIA
DAVIS MEDICAL CENTER
SACRAMENTO, CALIFORNIA

Plain Films
Excretory Urography
Ultrasound
Computerized Tomography
MRI
Biopsy
Case 1/2
Diagnosis
A. RCC, RCC
1
B. RCC, Artifact
C. Artifact, RCC
Dromedary Hump
D. Artifact, Artifact
2
Upper Pole of the Left Kidney
Ultrasound
Case 3




Cyst vs. Solid
RCC can be hypo, iso,
or hyperechoic
Misses 50% of solid
masses 2.5 cm or less
on routine scans
Good for vascular
invasion
Case 4
SIMPLE CYST ??
1
Potential Pitfalls







Base CT only
No Base CT
CM phase
Pseudoenhancement Cysts
Poor Enhancement RCC
Bosniak III & IV
Venous Streaming
NON CONTRAST CT

Calculi

Calcifications

Baseline for renal mass densitometry

Remember that 33% on non-Contrast CTs for
Flank Pain have Stone Disease*
*Rucker CM et al
Radiographics 2004
NON-STONE CT FINDINGS

Adnexal mass

Appendicitis

Diverticulitis
Non Contrast CT – Renal Etiologies
Pyelonephritis
RCC




Pancreatitis
Aortic Disease
Biliary Disease
Renal Disease
TCC
Renal Infarction
Renal Vein Thrombus
Renal Artery Aneurysm
Diagnosis Case 5
Non Contrast CT – Renal Etiologies
Pyelonephritis
RCC
TCC
Renal Infarction
All maybe
missed
A) Hydronephosis
B) Pyleonephritis
C) Renal Infarct
D) Renal Mass
E) Can’t tell
Renal Vein Thrombus
Renal Artery Aneurysm
2
Pyleonephritis-US
“Solid masses within the solid organs
cannot be excluded without IV
administration of contrast”
or
“Lack of IV contrast limits this scan”







Normal
Enlarged Kidney
Loss of Corticomedullary Differentiation
Hypoechoic (?edema)
Hyperechoic (?Hemmorhage)
Poor Perfusion (Power Doppler)
Poor Perfusion (CEUS)
Right Flank Pain Renal Abscess
Cystic or Solid? Case 6
Xanthogranulomatous
Pyelonephritis
Potential Pitfalls







Base CT only
No Base CT
CM phase
Pseudoenhancement Cysts
Poor Enhancement RCC
Bosniak III & IV
Venous Streaming
3
Corticomedullary Phase (CMP)
Most common phase to see kidneys in with MDCT

CM

Worst overall phase to evaluate kidneys
Cortex and medulla? 100 HU difference
Pitfalls: Can miss hyperdense cortical
masses and hypodense medullary
masses, especially papillary renal cell.
CM
Histologic Subtype
Table 2. Quantitative analysis of spiral CT
X
X
Prevalence
(%)
Clear Cell RCC
71
Papillary RCC
10
Chromophobe RCC
5
Hereditary cancer syndromes
5
Multilocular cystic RCC
1
Collecting duct carcinoma
1
Mucinous tubular and spindle cell carcinoma
1
Neuroblastoma‐associated RCC
1
Xp11.2translocation‐TFE3 carcinoma
1
Unclassified lesions
4
Bai X, Wu CL. Renal cell carcinoma and mimics: pathologic primer for radiologists. AJR Am J Roentgenol. 2012 Jun;198(6):1289‐93
Papillary RCC
Cyst Psedoenhancement

Problem:
Multidector CTs have more
pseudoenhancement than prior CTs
Papillary subtype of RCC with little
enhancement.
8 month follow-up
20 month follow-up
4
Clear Cell RCC
Nephrographic PhaseThe Star of Renal Mass
Imaging
Papillary RCC
Sun, M. R. M. et al. Radiology 2009;250:793-802
Solid Renal Mass (Adult)
Multiple Solid Masses
Common
 RCC
 Abscess, Focal Pyleonephritis
 Angiomyolipoma
 Oncocytoma
 Cyst, Infected or Hemorrhagic
 Hematoma
 Infarct
 Metastasis
 Hypertrophied column of Bertin; dromedary hump
 Lymphoma
VON HIPPEL-LINDAU
VHL







HEMANGIOBLASTOMA CEREBELLUM
HEMANGIOMAS OF RETINA
HYPERNEPHROMA
HEMANGIOMA OF LIVER
PHEOCHROMOCYTOMAS
PANCREATIC TUMORS-CYSTADENOMA
PANC. CYSTS, CYSTS AND CYSTS
1566159
5
TUBEROUS SCLEROSIS
Another Case on US
Diagnosis



TUBERS
CNS  NODULES
 GIANT CELL ASTROCYTOMA
RENAL - ANGIOMYOLIPOMA
- LYMPHANGIOMA, RCCs 1-2%
- CYSTS (MULTIPLE)

EYE – RETINAL HAMARTOMA

HEART – RHABDOMYOMA

LUNGS - LYMPHANGIOLEIOMYOMATOSIS
8256654
1952288
Think of Thin Reconstructions or
Reformated Images
Dx:AML
Catalano, O. A. et al. Radiology 2008;247:738-746
Copyright ©Radiological Society of North America, 2008
“Pixel Distribution Analysis: Clear Cell
RCC. vs. AML…?

AML

Only visible fat on CT can reliable classify
as AML
Pixel analysis with commericially available
software, not able to distiguish CCRCC
from AML.
RCC
Catalano OA et al
Rad vol 247(3):738-746, June 2008
Catalano, O. A. et al. Radiology 2008;247:738-746
Copyright ©Radiological Society of North America, 2008
6
Dx ? Case 12





Dx?
A) RCC
B) Angiomyolipoma
C) Post RFA
D) Liposarcoma
E) Met
Lymphoblastic
lymphoma 2 mos
F/U
1848381
Lymphoblastic
lymphoma
Case 13
Renal Lymphoma






1255887


Lymphoma of kidneys

41 y/o female
Common in widespread disease
Primary lymphoma very rare
Hematogenous spread or direct
invasion
50-70% bilateral
Multiple masses
50%
Hilar mass infiltrating kidney 25%
Renal enlargement
10%
Perirenal
10%
Solitary mass
5%
Is Segmental Enhancement Inversion…a
reliable sign for..Oncocytoma.”
1873068




Arterial

Inversion 1
Segments no Inversion 1
Central Scar 2
Central Necrosis 4
No segments 11
Oncocytoma
Delayed
McGahan JP, Lamba R, Fisher J et al.
Am J Roentgenol. 2011 Oct;197(4):W674-9.
7
Percutaneous Renal Intervention
Biopsy of Renal Mass





Biopsy

Prone-Diaphragm
Prone-Angle Needle or Gantry
Ipsilateral Side Down
Supine Through Stomach
Supine Through Liver
Supine Hydrodissection
Challenges in abdominal/pelvic biopsy techniques
McGahan JP Abd. Imaging 2013
CT-guided biopsy of Renal Masses
before RFA





Biopsy Technique
88.8% diagnostic
95% malignant
19 gauge co-axial system
22 FNA- min 2 samples
20 core-min 2 samples
Dx Non T Dx%
Fine-needle aspiration
73 18
91
80.2
Core
60 29
89
67.4
Fine-needle aspiration sample only
Core sample only
Both fine-needle aspiration and core
4 0
1 1
51 10
4
2
87
100.0
50.0
58.6
FNA diagnostic and core nondiagnostic
18
87
20.7
FNA nondiagnostic and core diagnostic
8
87
9.2
N
A
N
A
Heilbrun ME et al
AJR 2007;188:1500-1505
Heilbrun ME et al
AJR 2007;188:1500-1505
Conclusion





Biopsy with 22 gauge
FNA and 20 Core
showed Poorly
Differentiated Ca from
Lung


US Blind Spots – LUP
Compare Echo Texture of Mass with Kidney
Utilize Power/Color Doppler
Pitfalls of Non Contrast CT
CM phase of CT – Miss Mass in Medulla
Minimal Enhancement of P-RCC
Use U/S Guided Renal Biopsy
8