Evaluation of incidental renal and adrenal masses.

Incidental renal or adrenal masses are sometimes found during imaging for problems unrelated to the kidneys and adrenal glands. Knowledgeable family physicians can reliably diagnose these masses, thereby avoiding unnecessary worry and procedures for their patients. A practical and cost-efficient means of evaluating renal lesions combines ultrasonography and computed tomographic scanning, with close communication between the family physician and the radiologist. Asymptomatic patients with simple renal cysts require no further evaluation. Patients with minimally complicated renal cysts can be followed radiographically. Magnetic resonance imaging is indicated in patients with indeterminate renal masses, and referral is required in patients with symptoms or solid masses. The need for referral of patients with adrenal masses is determined by careful assessment of clinical signs and symptoms, as well as the results of screening laboratory studies and appropriate radiologic studies. Referral is indicated for patients with incidental adrenal masses more than 6 cm in greatest diameter. Appropriate laboratory screening tests include the following: a 24-hour urinary free cortisol measurement for patients with evidence of Cushing's syndrome; a 24-hour urinary metanephrine, vanillylmandelic acid or catecholamine measurement for patients with evidence of pheochromocytoma; and a serum potassium level for patients with evidence of hyperaldosteronism.