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A 56-year-old man with hypertension presents with a 2-week history of left-sided flank pain. Urinalysis shows microscopic hematuria and a CT scan (Figures 71-1 and 71-2) demonstrates a solid left renal mass. Work-up for metastatic disease was negative. A biopsy confirmed renal cell carcinoma and a radical nephrectomy was performed.
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Renal tumors are a heterogeneous group of kidney neoplasms derived from the various parts of the nephron. Each type of tumor possesses distinct genetic characteristics, histologic features, and, to some extent, clinical phenotypes that range from benign (approximately 20% of small masses) to high-grade malignancy. Ninety percent to 95% of kidney neoplasms are renal cell carcinomas (RCCs).1,2
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- RCC comprises 2% to 3% of all malignant diseases in adults and is the seventh most common cancer in men and ninth most common cancer in women.2
- An estimated 60,920 cases were diagnosed and approximately 13,120 deaths occurred in 2011 from kidney and renal pelvis cancer.3 The age-adjusted incidence rate was 14.6 per 100,000 persons with a median age at diagnosis of 64 years.3
- Lifetime risk of kidney and renal pelvis cancer is 1.56% (1 in 63 people will be diagnosed during their lifetime).3 These cancers are more common in men than women (approximately 2:1).
- Approximately 2% to 3% of cases are familial (e.g., von Hippel-Lindau syndrome).2
- Metastatic disease at presentation occurs in 23% to 33%; the most common sites of distant metastases (in descending order) are lung (with or without mediastinal or hilar nodes), bone, upper abdomen (including the tumor bed, adrenal gland, contralateral kidney, and liver), brain, and other sites (e.g., skin, spleen, heart, diaphragm, gut, connective tissue, and pancreas).4
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The majority of renal tumors fall into the following categories:1,2
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- Clear cell carcinoma (from high lipid content) (60% to 80%).
- Papillary carcinoma (5% to 15%), further delineated into type 1 and the more aggressive type 2.
- Chromophobic tumors (3% to 10%) and other rare subtypes, such as medullary, which occurs almost exclusively in patients with sickle cell trait.
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- Smoking (relative risk 2 to 3).1,2
- Obesity.
- Hypertension.
- Acquired cystic disease and end-stage renal disease, including dialysis treatment.
- Family history of the disease.
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Most presentations are incidental (identified during other tests) and, consequently, ...