Scintigraphic study of extra-adrenal ganglioneuroma in a patient with overlap between multiple endocrine neoplasia types 1 and 2

A 27-year-old woman was diagnosed with a pituitary prolactinoma. Seven years later, when she was 34, an abdominal mass was incidentally discovered and ascribed to the right adrenal gland on the basis of evidence from ultrasonography, computed tomography, and arteriography. Adrenal scintigraphy with Se-75 selenomethylcholesterol imaged both adrenal glands, but the right gland was distorted, suggesting external compression. I-131 MIBG was not taken up by the mass. At surgery, an extra-adrenal ganglioneuroma was found and excised. This case represents an overlap between multiple endocrine neoplasia types 1 and 2. The failure of the ganglioneuroma to concentrate MIBG was likely caused by secretory inactivity of a biologically mature tumor.