Renal Cell Carcinoma Renal cell carcinomas account for 90–95% of malignant neoplasms arising from the kidney. Notable features include resistance to cytotoxic agents, infrequent responses to biologic response modifiers such as interleukin (IL) 2, and a variable clinical course for patients with metastatic disease, including anecdotal reports of spontaneous regression. Epidemiology The incidence of renal cell carcinoma continues to rise and is now nearly 51,000 cases annually in the United States, resulting in 13,000 deaths. The male to female ratio is 2:1. Incidence peaks between the ages of 50–70, although this malignancy may be diagnosed at any age. Many environmental factors have. | Chapter 090. Bladder and Renal Cell Carcinomas Part 5 Renal Cell Carcinoma Renal cell carcinomas account for 90-95 of malignant neoplasms arising from the kidney. Notable features include resistance to cytotoxic agents infrequent responses to biologic response modifiers such as interleukin IL 2 and a variable clinical course for patients with metastatic disease including anecdotal reports of spontaneous regression. Epidemiology The incidence of renal cell carcinoma continues to rise and is now nearly 51 000 cases annually in the United States resulting in 13 000 deaths. The male to female ratio is 2 1. Incidence peaks between the ages of 50-70 although this malignancy may be diagnosed at any age. Many environmental factors have been investigated as possible contributing causes the strongest association is with cigarette smoking accounting for 20-30 of cases . Risk is also increased for patients who have acquired cystic disease of the kidney associated with end-stage renal disease and for those with tuberous sclerosis. Most cases are sporadic although familial forms have been reported. One is associated with von Hippel-Lindau VHL syndrome which predisposes to renal cell carcinomas retinal hemangioma hemangioblastoma of the spinal cord and cerebellum and pheochromocytoma. Roughly 35 of individuals with VHL disease develop renal cell cancer. An increased incidence has also been reported for first-degree relatives. Pathology and Genetics Renal cell neoplasia represents a heterogeneous group of tumors with distinct histopathologic genetic and clinical features ranging from benign to highgrade malignant Table 90-3 . They are classified on the basis of morphology and histology. Categories include clear cell carcinoma 60 of cases papillary tumors 5-15 chromophobic tumors 5-10 oncocytomas 5-10 and collecting or Bellini duct tumors 1 . Papillary tumors tend to be bilateral and multifocal. Chromophobic tumors have a more indolent clinical course and oncocytomas are considered
