Adult renal tumours

Question 1

What are the differentials of clear cell renal cell carcinoma in the kidney?

Answer 1

Other primary renal tumours with clear cell morphology eg: - clear cell papillary rcc - multilocular cystic rcc

Question 2

What is the pattern of staining of CA9 in clear cell papillary rcc?

Answer 2

Cup shaped basolateral staining (no apical/luminal staining)

Question 3

List the WHO Classification of renal cell tumours

Answer 3

1. Clear cell RCC
2. Multilocular cystic renal neoplasm of LMP
3. Papillary RCC
4. Hereditary leiomyomatosis and RCC-associated RCC
5. Chromophobe RCC
6. Collecting duct carcinoma
7. Renal medullary carcinoma
8. MiT family translocation RCC
9. SDH-deficient RCC
10. Mucinous tubular and spindle cell carcinoma
11. Tubulocystic renal cell carcinoma
12. Acquired cystic disease-associated RCC
13. Clear cell papillary RCC
14. Papillary adenoma
15. Oncocytoma

Question 4

What are the benign renal cell tumours according to WHO?

Answer 4

Oncocytoma

Papillary adenoma

Question 5

Describe the categories of tumours of kidney according to WHO

Answer 5

1. Renal cell
2. Metanephric
3. Nephroblastic and cystic
4. Mesenchymal (divided into mainly adults and mainly children)
5. Mixed epithelial and stromal tumour family
6. Neuroendocrine
7. Haematopoetic
8. Germ cell
9. Metastatic

Question 6

What are the metanephric tumours of the kidney?

Answer 6

Met. adenoma

Met. adenofibroma

Met. stromal tumour

Question 7

What are the mesenchymal tumours mainly seen in adults?

Answer 7

1. LMS (including renal vein LMS)
2. Angiosarc
3. Rhabdo
4. Osteosarc
5. Synovial sarcoma
6. EWS
7. AML
8. Epithelioid AML
9. Leiomyoma
10. Haemangioma (and lymphangioma)
11. Haemangioblastoma
12. Juxtaglomerular cell tumour
13. Renomedullary interstitial cell tumour
14. Schwannoma
15. SFT

Question 8

What are the mixed epithelial and stromal tumours?

Answer 8

Adult cystic nephroma

Mixed epithelial and stromal tumour

Question 9

What are clinical risk factors of RCC?

Answer 9

Obesity

Smoking

HTN

Acquired cystic kidney disease

Occupational exposure

Question 10

List syndromes associated with renal tumours (and which tumours they are associated with)

Answer 10

1. Von Hippel-Lindau (RCC, haemangioblastoma, cysts)
2. Birt-Hogg Dube (RCCs of various types - clear cell, chromophobe, papillary, oncocytoma, hybrid oncocytic tumour -> chromophobe/oncocytoma)
3. Beckwith-Wiedemann (Wilm’s tumour)
4. WAGR (Wilm’s tumour)
5. Denys-Drash (Wilm’s)
6. Hereditary papillary RCC syndrome (multiple bilateral type 1 prcc)
7. Hereditary leiomyomatosis and rcc syndrome (type 2 papillary rcc and leiomyomas)
8. SDH-RCC (RCC with particular histologic features)
9. HyperPTH-jaw tumour syndrome (MEST, papillary RCC)
10. Tuberous sclerosis (AML)
11. Familial PTC syndrome (oncocytomas)

Question 11

The ISUP grading system is used for which tumours?

Answer 11

Clear cell RCC

Papillary RCC

Question 12

Describe the ISUP grading system for renal tumours

Answer 12

Grade 1: nucleoli absent/inconspic/basoph at x400

Grade 2: nuc conspic/eosinoph at x400, visible but not prominent at x100

Grade 3: nucleoli conspic/eosinoph at x100

Grade 4: Marked pleomorphism, giant cells, rhabdoid/sarcomatoid differentiation

Question 13

How does clear cell RCC metastasize and to where?

Answer 13

Haematogenous (renal sinus - important to report, renal vein)

Goes to lungs, liver, adrenal, bone, soft tissue, and elsewhere - often seen in random places

Question 14

What is the immunophenotype of clear cell RCC?

Answer 14

PAX8+

CAIX - membranous + (complete - vs basolateral of papillary rcc)

CK, EMA+

CK7 rare (isolated cells, helps to diff from chromophobe which is ++)

CD10+ membranous (not specific)

Question 15

How can the VHL gene be altered in clear cell rcc?

Answer 15

Deletion

Methylation/silencing

Mutation

Question 16

What are the histologic features of multilocular cystic renal neoplasm of LMP?

Answer 16

Entirely cystic

Multiple cysts - lined by single layer of low grade nuclei

Septa containing individual or groups of clear cells without expansile growth

Can have calcification and ossification

Question 17

What is the differential diagnosis of multilocular cystic renal neoplasm of LMP?

Answer 17

1. Clear cell RCC w/ cystic necrosis
2. Tubulocystic carcinoma
3. Cystic nephroma
4. Clear cell papillary RCC w/ predominantly cystic config
5. Benign multilocular renal cortical cysts

Question 18

What is the underlying genetic alteration in multilocular cystic renal neoplasm of LMP?

Answer 18

VHL deletion (same as clear cell RCC)

Question 19

What is the etiology of papillary RCC?

Answer 19

ESRD with scarring

Acquired cystic disease

Genetic syndromes (hereditary PRCC syndrome, Birt-Hogg-Dube)

Question 20

What is the radiologic appearance of papillary RCC?

Answer 20

Can appear hypovascular due to spontaneous tumour necrosis

Often has foci of calcification

Question 21

What are the histologic features of papillary RCC?

Answer 21

Circumscribed, prominent pseudocapsule

Papillae (can be tightly packed and appear tubular or solid)

FV cores with foamy macrophages and psammoma bodies

Cores can be oedematous or hyalinized

5% show sarcomatoid change

Question 22

What is the immunoprofile of papillary RCC?

Answer 22

CK+

AMACR+

CD10+

CK7+ (more in type 1 than type 2)