Answer and Discussion of Quiz Set: K-004

1.    Which of the following is not true regarding chromophobe renal cell carcinoma?

A.  Most cases are diagnosed at stage 1 or 2 and have good prognosis

B.  Fuhrman or ISUP grading should not be applied as histologic grade is not a good prognostic indicator

C.  Metastasis is rare in chromophobe renal cell carcinoma and involve only 6% of cases

D.  In order to qualify for a diagnosis of the eosinophilic variant of chromophobe carcinoma, at least 80% of the cells have to be oncocytic

E.  Chromophobe renal cell carcinoma arises from the intercalated cells of the cortical collecting duct.

Answer and Discussion: The answer is (B). In general, chromophobe renal cell carcinoma is a low-grade renal cell carcinoma with better prognosis than clear cell and papillary renal cell carcinoma. It comprises about 5-10% of all renal neoplasm. In contrast to the later two, Furhman nuclear grade or ISUP grade has no prognostic value for chromophobe renal cell carcinoma and therefore should not be applied.