renal cell carcinoma, clear cell type; clear cell (conventional) renal cell carcinoma

Epidemiology

75-85% of renal carcinomas

Pathology

• may arise from the proximal convoluted tubules within the renal cortex
• propensity for vascular, rather than lymphatic, invasion

Microscopic pathology

• clear cytoplasm, not necessarily all cells
• variable nuclear pleomorphism
• PAS/glycogen: positive
• Hale's colloidal iron stain: negative
• mucin: negative
• oil red O (lipid): positive

Genetics

• 3p-, vhl gene often deleted,
• pbrm1 mutation in 50% of cases
• also see kidney cancer

Clinical manifestations

• compared with other histologic types of RCC, more likely to be symptomatic

Laboratory

Immunocytochemistry:

• low molecular weight cytokeratin: positive
• high molecular weight cytokeratin: negative
• epithelial membrane antigen: positive
• vimentin: positive
• carbonic anhydrase: positive
• CD10: positive
• RCC antibody: positive
• placental alkaline phosphatase (PLAP): positive
• carcinoembryonic antigen (CEA): negative
• S100: negative
• band 3 protein: negative
• inhibin: negative Differential Diagnosis (histologic):

adrenal cortical carcinoma

urothelial carcinoma of renal pelvis

papillary renal cell carcinoma

chromophobe renal cell carcinoma

oncocytoma

melanoma

More general terms

• renal cell carcinoma (hypernephroma, Grawitz tumor)
• clear cell carcinoma

More specific terms

• renal cell carcinoma, clear cell type (hereditary renal cancer associated 1)