False-positive 123I-metaiodobenzylguanidine scintigraphy in a patient with a gastrointestinal stromal tumor presenting as a left adrenal incidentaloma.

Anatomic structures and tumors that develop in neighboring tissues to the adrenal glands may be confused with primary adrenal tumors. 123I- metaiodobenzylguanidine (MIBG) scintigraphy is specific for diagnosing pheochromocytomas and paragangliomas; however, it has been reported that 123I-MIBG may accumulate in neuroendocrine tumors as well as other tumors. Clinicians should recognize the limitations of imaging studies and the uncertainty of an imaging-based preoperative diagnosis.