[Primary renal carcinoid tumor]

Primary renal carcinoid tumors are very rare, so their characteristic imaging findings have not been well defined. We describe the case of a man with a large right renal mass associated to a retroperitoneal lymph-node conglomerate. Increased urine concentrations of 5-hydroxy-indole-acetic acid and the histologic findings led to the diagnosis of primary renal carcinoid tumor. We review the epidemiology, clinical presentation, and findings at ultrasonography, computed tomography, and magnetic resonance image for primary renal carcinoid tumors.