Bean type - Urothelial cell CA of renal pelvis - Lymphoma - Metastasis Ball type - Renal cell carcinoma (RCC) - Oncocytoma - Angiomyolipoma - Multilocular cystic nephroma

1. Topic
Renal neoplasm
Suchanar-Sutatta R1

2. Must know: pathologic image
of the KUB system
5.4 Tumor
5.4.1 Benign tumors
5.4.4.1 Angiomyolipoma
5.4.1.2 Oncocytoma
5.4.1.3 Multilocular cystic nephroma
5.4.2 Malignant tumors
5.4.2.1 Wilm's tumor (ped)
5.4.2.2 Renal cell carcinoma
5.4.2.3 Urothelial cell CA of renal pelvis,
ureter and bladder
5.4.2.4 Lymphoma
5.4.2.5 Metastasis

3. Approach renal masses
Solitary expansible type (BALLS)
COMMON
- Cyst
- Renal cell carcinoma (RCC)
UNCOMMON
- Angiomyolipoma
- Abscess
- Metastases
- Cystic nephroma
RARE
- Metanephric adenoma
- Localized renal cystic disease
- Focal xanthogranulomatous pyelonephritis
Infiltrating type (BEANS)
COMMON
- Transitional cell carcinoma
(urothelial carcinoma,
unspecified)
- Pyelonephritis
UNCOMMON
- Squamous cell CA
- Infiltrating RCC
- Lymphoma
- Metastases
- Renal infarct
RARE
- Renal medullary carcinoma
- Collecting duct carcinoma
The requisites Genitourinary imaging, 3rd ed

4. Infiltrative renal masses
Bean type
• Urothelial cell CA of renal pelvis
• Lymphoma
• Metastasis

5. Urothelial cancers
• 90% are TCCs, 9% are squamous cell carcinoma
and 1% are mucinous adenocarcinoma
• Most common in urinary bladder, then in renal
pelvis, least in ureter (94% : 5% :1%)
o Lower third ureter (60% -75%) > upper ureter
• Incidence peak in 6 -7th decade of life
• Male to female ratio is 3:1
• Clinical presentation usually hematuria
Ronan FJ Browne et al, Radiographics 2005

6. Renal transitional cell carcinoma
• < 10% of renal tumors
• Most common tumors of the collecting system
• Most frequently arises in the renal pelvis,
followed by the infundibular and caliceal regions
Ronan FJ Browne et al, Radiographics 2005
Raghunandan Vikram et al, AJR 2009
1
3
2
**An infiltrating tumor
involves the renal pelvis
 usually infiltration of
the renal parenchyma

7. • 2% - 4% bilaterally
• 40% of patients with upper tract TCC develop
bladder cancer
• 2–4% of patients with bladder cancer develop
upper tract TCC
Renal TCC

8. Multifocal TCCs
Both pelvicalyceal moieties of
a left duplex kidney
Obstructed right ureteric
tumor
Imaging in Oncology, Second Edition
Filling defects

9. Multifocal TCCs
2 Enhancing
masses in
Left ureter
2 Enhancing
masses in
urinary bladder

10. Renal TCC
• Patho
o 85% : superficial, papillary
tumors with a broad base and
frondlike morphologic structure
o 15% : Pedunculated or diffusely
infiltrating tumor
Ronan FJ Browne et al, Radiographics 2005
Advanced
Low-grade

11. Risk factors of upper TCCs
• Tobacco use (> 40 pack-years are 5 times more likely
to develop TCC than nonsmokers)
• Balkan nephropathy (100–200 times greater risk)
• Phenacetin abuse
• Chemical carcinogen (aniline, benzidine, aromatic
amines, azo dyes)
• Cyclophosphamide treatment
• Heavy caffeine consumption
• Stasis of urine, and structural abnormalities such as
horseshoe kidney
Raghunandan Vikram et al, AJR 2009

12. Pattern of tumor spread
• Multiple
• Recurrent and metachronous tumors
1. Direct invasion into retroperitoneum
2. Lymphatic route
3. Hematogenous
• Metastases from ureteral TCC are more common due
to the thin wall and rich lymphatic drainage of ureter
• Commonly involve retroperitoneal lymph node
• Most common sites for metastases are the liver, bone,
and lungs
Raghunandan Vikram et al, AJR 2009

13. Imagings
• Best diagnostic clue: Irregular filling defect in renal
pelvis with tumor infiltration of parenchyma
• Excretory urography, traditionally most widely used
technique
• CT urography accepted as a primary diagnostic
investigation
o Advantage: - assess collecting system and ureter of
nonfunctioning kidney
: - staging and assessment of the upper
urinary tract in a single examination
Raghunandan Vikram et al, AJR 2009

14. • Assess degree of hydronephrosis and
guide interventional procedure
• Central soft-tissue mass in the echogenic renal sinus, with
or without hydronephrosis
Ultrasound
Browne et al, Radiographics 2005

15. Excretory urography
a solitary renal pelvic
filling defect
Ronan FJ Browne et al, Radiographics 2005
RD Dunnick et al, Uroradiology 5thed
Intraluminal filling defects
- Tumor (benign or malignant)
- Blood clot
- Sloughed papillae
- Mycetoma (fungus ball)
a diffuse infiltrating TCC
involving the Rt lower
pole calix with
irregularity of mucosa

16. Common pattern of abnormalities
1. Filling defects in the renal collecting system; single or
multiple, smooth or irregular, and sometimes stippled
“The stipple sign” - contrast medium in the tumor’s
papillary fronds
Raghunandan Vikram et al, AJR 2009
Ronan FJ Browne et al, Radiographics 2005

17. 2. Filling defects in a distended calyx secondary
to a tumor in the infundibulum
Common pattern of abnormalities
Ronan FJ Browne et al, Radiographics 2005
“Calyceal amputation”
complete obstruction
“calyceal dilatation”
incomplete obstruction
Raghunandan Vikram et al, AJR 2009

18. 3. Filling defects in the ureter with or without
proximal hydroureteronephrosis
Common pattern of abnormalities
Tumor obstructs infundibulum
causing hydronephrosis of 1 calyx
Raghunandan Vikram et al, AJR 2009
Ronan FJ Browne et al, Radiographics 2005

19. Oncocalyx: calyces distended by tumor
Excretory urography
Imaging in Oncology, Second Edition

20. Calculi
CT urography phases
Vascular
abnormalities Urothelium
3. nephrographic phase1. Preenhancement 4. Excretory phase
[2. Late arterial, early
corticomedullary phase]
Renal
parenchyma

22. Sessile filling defect in the excretory phase, which
expands centrifugally with compression of the
renal sinus fat
Imaging in Oncology, Second Edition
CT urography
Small soft tissue mass in
medial upper pole calyx
Contrast medium in the
calyx outlines the tumor

23. Lymphoma
Borhani et al, Diagnostic imaging genitourinary 3rded
• Primary: very rare
• Secondary: hematogenous spread or extension of
retroperitoneal disease
o Silent and late involvement
• Best diagnostic clue
o Discrete or infiltrative mass in setting of systemic adenopathy
o Bilateral
o Variable size; multiple small mass > large, infiltrative masses

24. Imagings
Borhani et al, Diagnostic imaging genitourinary 3rded
• US&Doppler: Solid, hypoechoeic lesion(s) internal flow
Enlarged left kidney with
heterogeneous echotexture
of the parenchyma
Rt kidney: ill-defined infiltration of the
renal sinus fat near the lower pole and a
focal hypoechoic mass

25. Typical CT patterns
1. Multiple renal masses (most common, 50-60%)
2. Direct Extension from retroperitoneal
adenopathy (25%–30%)
3. Solitary mass (10-25%)
• Perirenal disease (<10%)
• Diffuse renal infiltration
Sheila Sheth et al, Radiographics 2006

26. Multiple renal masses
- Small, hypoattenuating
masses bilaterally
- Bilateral renal masses
- Homogeneous
attenuation, smooth
borders, low contrast
enhancement
- Peritoneal adenopathy
BA Urban et al, Radiographics 2000
- 1-3 cm

27. • A large retroperitoneal mass invading or displacing
the adjacent kidney
• Rare occlusion or thrombosis of renal arteries and veins
despite tumor encasement
• Hydronephrosis and obstruction is common
Contiguous retroperitoneal
extension
BA Urban et al, Radiographics 2000
Renal arteries

28. Solitary mass
- A 2.6-cm homogeneous
hypovascular mass in lower pole
of left kidney (38 HU)
- Retroperitoneal nodes
D Ganeshan et al, AJR 2013
• Hypovascular and minimal enhancement
• Homogeneous attenuation
• Low-attenuation area but cystic change
(calcium, bleed or necrosis)
• Plain CT differentiates renal lymphoma from a
hyperdense benign cyst
o A benign hyperdense cyst ≥ 70 HU
o Renal lymphomas 30 – 50 HU

29. • Homogeneous perinephric soft tissue
compressing the normal parenchymal without
causing significant impairment of renal function
• Thickening of Gerota fascia, plaques and nodules
in the perirenal space
Perirenal disease

30. • Nephromegaly with preservation of renal
contour
• Always bilateral
• Difficult diagnosis and relies on global
renal enlargement
Infiltrative disease
- Minimal renal enlargement bilaterally
- Subtle involvement by lymphoma

31. • Collecting system often encased and strethed
rather than displaced
• IV contrast to demonstrate
o Loss of the normal differential enhancement
between the cortex and the medulla in the
corticomedullary phase
o Renal parenchyma is replaced by poorly
marginated low-attenuation lesions
Infiltrative disease
Nephrographic phase
- Bilateral renal enlargement
- Heterogeneously decreased
enhancement of the renal parenchyma
Bruce A et al, Radiographics 2000

32. • From primary cancer of lung, breast, colon, melanoma
• Best diagnostic clue
oMultiple renal masses in patient with primary
malignancy ± perirenal&retroperitoneal lesions
oHematogenous > direct invasions
• Typically small, multifocal, and bilateral, exhibiting an
infiltrative growth pattern
• Much less contrast enhancement than normal renal
parenchyma
Renal metastases
Borhani et al, Diagnostic imaging genitourinary 3rded

33. Imagings
CT
• Often nonspecific features
• Multiple solid, hypoattenuating renal masses
○ Typically located in renal cortex or corticomedullary junction
○ Variable enhancement (depend on primary tumor type)
– Hypervascular: Melanoma, breast, neuroendocrine
Heterogeneously enhancing
renal masses with areas of
necrosis due to metastatic
non-small cell lung carcinoma

34. • Hypodense multiple metastases in liver, kidneys, and spleen
in a known case of carcinoma rectum
Imagings

35. MR
• T1: Typically iso- to hypointense
• T2: Typically hyperintense
Imagings

36. Solitary expansible renal masses
Ball type
• Renal cell carcinoma (RCC)
• Oncocytoma
• Angiomyolipoma
• Multilocular cystic nephroma

37. Renal cell carcinoma
• 6th to 7th decades
• Male predominance
• Risk: tobacco, obesity, uncontrolled
hypertension, first-degree family members of
patients with RCC, VHL, chronic hemodialysis
or peritoneal dialysis, TS
• The classic triad: hematuria, flank pain,
palpable abdominal mass

38. Type of RCC

39. Type of RCC
• 70% – 80% = Clear cell RCC
• 10% – 15% = Papillary RCC
• 5% = Chromophobe type
• 1% = Collecting duct
• 5% = Oncocytoma

40. Type of RCC
• Clear cell RCC
o 60% Sporadic = defect in VHL suppressor gene
• Papillary RCC
o Abnormalities of chromosome 7 and 17 and loss
of chromosome Y
o Metastasis: aggressive
o Type I: sporadic, good prognosis
o Type II: inherited, poor outcome

41. Type of RCC
• Chromophobe type
o The Birt-Hogg-Dube syndrome
• Hair follicle hamartoma
• Frequent pneumatosis from ruptured lung cysts
• Often have chromophobe tumor or mixed
chromophobe and oncocytoma

42. Type of RCC
• Collecting duct/ renal medullary CA
o An aggressive tumor
o Young, male, sickle cell trait
o Usually presented venous and lymphatic invasion
• CT
o Infiltrative pattern
o Heterogeneous enhancement
o Typically invaded renal sinsus
o Caliectasis without pelviectasis

43. Renal cell carcinoma

44. Renal cell carcinoma
CT
o Hypervascular mass and heterogeneous: clear cell
o Homogeneous (papillary<3cm)
o Poorly enhancing(10-20 HU) = papillary, chromophobe
o Calcification:
• Thin peripheral curvilinear: cyst
• Central or thick mural calcification: RCC
o Typically exophytic but may be intrarenal or infiltrative
o Necrosis
o Incidental finding

45. Renal cell carcinoma
• 15% of RCCs have a substantial cystic component:
unilocular, multilocular, discrete mural nodule in
cystic mass
• Perinephric hemorrhage: RCC or AML is most
common cause of spontaneous perinephric
hemorrhage in non being anti-coagulated patient

46. Renal cell carcinoma
• Extension of the disease
o Perinephric fat
o Renal vein or inferior vena cava
o Regional lymphadenopathy
o Adjacent organs
o Distant metastasis: mc = lungs, mediastinum,
bones, liver
less common = contralateral kidney, adrenal gland,
brain, pancreas, mesentery, abdominal wall

47. Renal cell carcinoma
Dystrophic calcifications

48. Thick mural calcifications
Multiple enhancing tumor nodules
Renal cell carcinoma

49. Cystic RCC

50. Perinephric hemorrhage

51. Brisk enhancement in 4-cm
exophytic ball-type mass at
right upper pole
Patho: Clear cell RCC
2-cm enhancing in lower pole
of left kidney
Patho: Clear cell RCC
Renal cell carcinoma

52. Contour abnormality in interpolar
region of the left kidney (36 HU)
Well-defined ball-type lesion
(65 HU)
Patho: papillary RCC
Renal cell carcinoma

53. Relatively homogeneous mass
Peripheral rim enhancement
A small focus of dystrophic
calcification
Patho: Chromophobe RCC
Renal cell carcinoma

54. Renal cell carcinoma
• Abnormal soft-tissue
attenuation in
retroperitoneum
• Perinephric fat infiltration
• Enlargement of left renal vein and
IVC due to intravenous invasion
• Abnormal pattern of parenchymal
enhancement in anterior hilar lip
on the left
• Retroperitoneal lymph nodes
Collecting duct

55. Renal cell carcinoma

56. MRI:
oSensitivity similar to CT
oHomogeneous tumors are isointense with
parenchyma on TlW and t2W
oIntravenous contrast (gadolinium-based)
enhances vascular tumors
oHypovascular tumors are better seen with
fat-saturation techniques
Renal cell carcinoma

57. Papillary renal carcinoma
Hypointense on TlW, T2W
Homogeneous after contrast
enhancement
Renal cell carcinoma

58. • Benign
• Male predominance
• 7th decade
• Incidental finding or symptom: flank mass,
pain, hematuria
Oncocytoma

59. • Benign
• CT:
o Ball-type solid, non–fat-containing mass
o Homogeneous
o Necrosis and hemorrhage are rare
o Calcification is rare
o Central stellate scar or “spoked-wheel”pattern of
vascular supply to the tumor
o Usually solitary, multifocal and bilateral tumors
can occur
• RCC and oncocytoma can be indistinguishable
Oncocytoma

60. Homogeneous right renal mass
Patho: oncocytoma
Left renal mass with
prominent central scar
Patho: oncocytoma
Oncocytoma

61. Ball-type mass with stellate
central scar arising from
anterior interpolar region of
left kidney
Presence of pseudocapsule at
posterior margin of the mass
Patho: oncocytoma
Oncocytoma

62. • Compose of angiomatous, myomatous, and
lipomatous tissues
• Typically small, asymptomatic, and an incidental
finding in middle-aged women
• 20% associated with tuberous sclerosis
Angiomyolipoma

63. U/S:
• Highly echogenic
• Depends on the fat content
Little fat = indistinguishable
from other renal masses
Very echogenicity = mimicked
by renal adenocarcinoma
• Hemorrhage = sonolucent
area
Angiomyolipoma

64. CT:
oWell defined
oCalcification or necrosis is rare
oThe vessels in an AML lack a complete
elastic layer and tend to be thick walled,
irregular, tortuous, and aneurysmal
oInternal hemorrhage may obscure the fat
• Large AML (>4cm in diameter): spontaneous
hemorrhage
Angiomyolipoma

65. Small fat containing mass in the
dorsal aspect of the left kidney
Angiomyolipoma

66. Tuberous sclerosis
bilateral renal masses
without fat content
"lipid-poor” AML
Tuberous sclerosis
Multiple bilateral
fatty tumors
Angiomyolipoma

67. AML with hemorrhage

68. • Benign
• Multilocular renal cyst, cystic adenoma,
lymphangioma, segmental multicystic kidney,
segmental polycystic kidney, cystic
hamartoma, benign cystic nephroma,
Perlmann tumor
• Two histologically distinct
oCystic nephroma: children and adults
oCystic partially differentiated
nephroblastoma: children
Multilocular cystic nephroma

69. CT:
o Large, averaging approximately 10 cm in diameter
o Well-circumscnoed lesion containing many cysts
of variable sizes
o Hypovascular
o Septations enhance after intravenous contrast
administration
o Large cysts: internal septation
o Herniation of the mass into the renal pelvis
o Surrounded by a thick fibrous capsule
o Hemorrhage and necrosis are uncommon.
Multilocular cystic nephroma

70. A multicystic mass in
the right kidney, which
herniate into the renal
pelvis