Tumors of the Kidney & Urinary Tract

Question 1

What’s this?

Answer 1

Papillary adenoma

Benign tumor that grows very little.

Question 2

Explain Fuhrman Nuclear Grades

Answer 2

Fuhrman Nuclear Grades is predictive of mortality rates and only looks at the nuclei.

The larger and more irregular the nuclei, the worse the prognosis.

Question 3

Which Fuhrman grades are depicted here?

Answer 3

Grades 1 and 2.

Grade 1 is top right and grade 2 is bottom left.

Pathology will typically only mention the grade 2 as it has worse prognosis.

Question 4

What Fuhrman grade is depicted here?

Answer 4

Grade 3

Question 5

What Fuhrman grade is depicted here?

Answer 5

Grade 4.

Large nuclei with irregular shape and all kind of different.

Question 6

What Fuhrman grade is depicted here?

Answer 6

Grade 4 with sarcomatoid features

Question 7

What is the most common type of renal cell carcinoma?

Answer 7

Clear cell

Question 8

What is the 2nd most common type of renal cell carcinoma?

Answer 8

Papillary

Question 9

What’s this?

Answer 9

Chromophobe renal cell carcinoma (rare, 5% of cases, low malignant potential)

Question 10

Chromophobe renal cell carcinoma is often confused with oncocytomas. How can you tell the difference?

Answer 10

Do an iron stain.

A = chromophobe

B = chromophobe with iron stain

C = oncocytoma

D = oncocytoma with iron stain

Question 11

Explain the genetics of clear cell renal cell carcinomas.

Answer 11

Both sporadic (95%) and familial (4%) renal cell carcinoma is caused by abnormalities in the VHL (Von Hippel-Lindau) gene (3p25.3) tumor suppressor gene.

It can be caused by a deletion, translocation, somatic mutation, or even hypermethylation.

In familial, all cells have this problem so there are usually hemangioblastomas of the cerebellum and retina, bilateral renal cysts, and multiple RCCs.

In sporadic, there is typically just one RCC.

Question 12

Explain the genetics of papillary renal cell carcinoma

Answer 12

These are not associated with the VHL (3p) changes.

These are most commonly caused by these cytogenetic abnormalities:

Familial: Trisomy 7, mutated activated MET

Sporadic: Trisomy 7, 16, 17, or loss of Y. Mutated, activated MET

Locus on chromosome 7 (MET locus) protooncogene:

Tyrosine kinase receptor for hepatocyte growth factor

Mutated in a proportion of the sporadic cases of PC

Question 13

What is an important difference between sporadic and hereditary renal cell carcinomas?

Answer 13

Focality

Question 14

What is the most important risk factor for Urothelial Carcinomas?

Answer 14

Smoking.

Other risk factors include chronic infections, solvents, and cyclophosphamide

Question 15

Are urothelial carcinomas more common in males or females?

Answer 15

Males. 3:1

Usually over 50 y/o

Question 16

Where can urothelial carcinomas occur?

Answer 16

Anywhere in the urinary tract (from renal pelvis to urethra)

Question 17

What’s the prognosis of urothelial carcinomas?

Answer 17

Depends on stage.

Question 18

What is being shown here?

Answer 18

Left: Dysplasia urothelial mucosa

Right: Carcinoma in situ of urothelial mucosa

Question 19

Which immunostain is diagnostic for urothelial carcinoma in situ?

Answer 19

CK20

It will show full thickness stain.