Painful leg mass
The moist purple exophytic lesion on the patient’s lower leg prompted him to seek care. Unfortunately, it was just the tip of the iceberg.
Renal cancer risk factors include tobacco use, obesity, renal cystic disease, and toxic occupational exposures (eg, cadmium). A genetic predisposition also appears to play a role.2 The classic presenting symptoms of renal malignancy include hematuria, a flank mass, and abdominal pain. Patients may experience a single symptom but rarely all 3, and many patients come in with nonspecific complaints of fever, sweats, weight loss, and fatigue.2
RCC also has a propensity for paraneoplastic syndromes that may present with anemia, hypercalcemia, or hepatic dysfunction.2 Unfortunately, many smaller renal lesions are asymptomatic, so as many as 55% of patients may present with metastatic disease at the time of initial presentation.3
The most common sites for renal metastatic disease are the lungs, bone, lymph nodes, brain, and contralateral kidney.2 Skin metastases, occurring in 2% to 10% of RCC cases, are less common and are often a sign of poorer prognosis.4 Men who have RCC are more likely to have skin metastases than women; the typical locations are the head, neck, and trunk.4
Is it RCC, or something else?
Signs and symptoms suggestive of possible renal malignancy (eg, hematuria, flank pain, weight loss, flank mass on exam) should prompt a work-up that includes abdominal imaging. The preferred imaging modality is a CT scan. Final tissue diagnosis is made on review of biopsy specimens obtained from the renal mass.
