ESSENTIALS OF DIAGNOSIS
Gross or microscopic hematuria.
Flank pain or mass in some patients.
Systemic symptoms such as fever, weight loss may be prominent.
Solid renal mass on imaging.
Kidney (renal cell) and renal pelvis carcinomas account for 3.8% of all adult cancers. In 2019 in the United States, it is estimated that approximately 73,820 cases of renal cell carcinoma will be diagnosed and 14,770 deaths will result. Renal cell carcinoma has a peak incidence in the sixth decade of life and a male-to-female ratio of 2:1. It may be associated with a number of paraneoplastic syndromes (see eTable 39–1).
Risk factors include physical inactivity, obesity, and diabetes mellitus. Cigarette smoking is the only known significant environmental risk factor. Familial causes of renal cell carcinoma have been identified (von Hippel–Lindau syndrome, hereditary papillary renal cell carcinoma, hereditary leiomyoma-renal cell carcinoma, Birt-Hogg-Dubé syndrome), and there is an association with dialysis-related acquired cystic disease and specific genetic aberrations (eg, Xp11.2 translocation), but sporadic carcinomas are far more common.
Renal cell carcinoma originates from the proximal tubule cells. Various histologic cell types are recognized (clear cell, papillary, chromophobe, collecting duct, and sarcomatoid).
Historically, 60% of patients presented with gross or microscopic hematuria. Flank pain or an abdominal mass was detected in approximately 30% of cases. The triad of flank pain, hematuria, and mass was found in only 10% of patients, and often a sign of advanced disease. Fever can occur as a paraneoplastic symptom (see eTable 39–1). Symptoms of metastatic disease (cough, bone pain) occur in 20–30% of patients at presentation. Due to the widespread use of ultrasound and cross-sectional imaging, renal tumors are frequently detected incidentally in individuals with no urologic symptoms. Consequently, there has been profound stage migration toward lower stages of disease over the last 20 years. However, population mortality rates have remained stable.
Contemporary studies suggest hematuria is present in less than 50% of patients. Erythrocytosis from increased erythropoietin production occurs in 5%, though anemia is more common; hypercalcemia may be present in up to 10% of patients. Stauffer syndrome is a reversible syndrome of hepatic dysfunction (with elevated liver tests) in the absence of metastatic disease.
Solid renal masses are often first identified by abdominal ultrasonography or CT. CT and MRI scanning are the most valuable imaging tests for renal cell carcinoma. These scans confirm the character of the mass and provide valuable staging information with respect to regional lymph nodes, renal vein or vena cava tumor thrombus, and adrenal or liver metastases. CT and MRI also provide valuable information regarding the contralateral kidney (function, bilaterality of neoplasm). Chest radiographs or CT exclude pulmonary metastases. Bone scans ...