title: Sporadic bilateral adrenal medullary hyperplasia: apparent false positive MIBG scan and expected MRI findings.
abstract: Adrenal medullary hyperplasia is a rare cause of clinical symptoms and biochemical findings identical to pheochromocytoma occurring mostly in multiple endocrine neoplasia patients. The scenario of positive MIBG scan, but no focal lesion found on CT and MRI led to diagnostic and management difficulties. Like pheochromocytoma, surgical excision can lead to clinical and biochemical recovery. We report this unusual case of sporadic bilateral adrenal medullary hyperplasia, with hypertension and biochemical abnormalities alleviated after surgical adrenalectomy. Based on T2 values reported in literature, high signal focal lesions may not appear on T2-weighted MRI images until development of frank pheochromocytoma. MIBG scan remains the most sensitive imaging modality for this condition.
authors.affiliation: Department of Radiology and Organ Imaging, United Christian Hospital, 130 Hip Wo Street, Kwun Tong, Kowloon, Hong Kong.
authors.forename: B C
authors.initials: BC
authors.lastname: Yung
authors.forename: T K
authors.initials: TK
authors.lastname: Loke
authors.forename: T W
authors.initials: TW
authors.lastname: Tse
authors.forename: M W
authors.initials: MW
authors.lastname: Tsang
authors.forename: J C
authors.initials: JC
authors.lastname: Chan
mesh_terms: D019797:3-Iodobenzylguanidine; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis; D000313:Adrenal Medulla / Q000000981:diagnostic imaging / Q000473:pathology*; D000315:Adrenalectomy; D000328:Adult; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia; D006973:Hypertension / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D008297:Male; D018813:Multiple Endocrine Neoplasia Type 2a / Q000175:diagnosis; D010673:Pheochromocytoma / Q000175:diagnosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine