Renal Scintigraphy with Tc-99m DTPA in Pheochromocytoma: Mistake or Not?

A 32-year-old man who reported abdominal pain and had an echographic diagnosis of “renal or extrarenal mass” (diameter, approximately 10 to 12 cm) underwent renal scintigraphy with 111 MBq (3 mCi) Tc-99m DTPA. The renal scan revealed increased uptake superior to the upper pole of the left kidney with normal renal function. Subsequently, the computed tomographic and magnetic resonance features showed a voluminous left paraaortic retroperitoneal mass, probably in the left adrenal compartment, of unknown nature. Results of a 24-hour urinary evaluation of vanillylmandelic acid were abnormal (59.5 mg; normal, 1 to 11 mg). Surgery and histologic examination confirmed the presence of a voluminous left adrenal pheocromocytoma.