title: Multimodality imaging of bilateral pheochromocytoma. A case report.
abstract: BACKGROUND
  Bilateral pheochromocytomas ( PHEO ) are rare, often hereditary and linked to a germline mutation of RET, VHL or SDHx. They also occur sporadically.
  
  
  METHODS
  We report a case of a 76 year old female hospitalized for biological investigations following symptoms of abdominal discomfort with recurrent hypertensive episodes. The hormonal work up results favoured a diagnosis of a PHEO (urinary and plasma metanephrines > 10 times normal). Radiological investigations (CT-MRI): identified bilateral adrenal masses (47 mm in the right adrenal, 26 mm in the left adrenal). Functional imaging with 123 I-MIBG scintigraphy showed intense uptake in the right adrenal mass with limited uptake in the left, probably related to a fixation of the normal adrenal medulla. Due to the strong suspicion of bilateral PHEO, further imaging with an 18F-FDOPA PET was performed. This revealed intense hypermetabolism of the right mass but the left mass had similar metabolism to the liver, thought to be unsuspicious for a PHEO. It was decided to proceed with a laparoscopic right adrenalectomy. Hormonal investigations performed post-operatively revealed persistently elevated metanephrines. An 18FFDG PET was performed, revealing an intense hypermetabolic focus in the left adrenal gland. A laparoscopic partial left adrenalectomy was subsequently performed 6 weeks after the initial right adrenalectomy.
  
  
  CONCLUSIONS
  This case highlights the possibility of false negative results using specific functional imaging. In these situations, 18F-FDG PET may be useful. The MRI signal has an indisputable value. Until today, no germline mutation was found in this patient.
authors.forename: Nunzia Cinzia
authors.initials: NC
authors.lastname: Paladino
authors.forename: Aoife
authors.initials: A
authors.lastname: Lowery
authors.forename: Carole
authors.initials: C
authors.lastname: Guérin
authors.forename: David
authors.initials: D
authors.lastname: Taïeb
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sebag
mesh_terms: D019797:3-Iodobenzylguanidine; D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D000315:Adrenalectomy; D000368:Aged; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D005188:False Negative Reactions; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D064847:Multimodal Imaging; D009378:Neoplasms, Multiple Primary / Q000000981:diagnostic imaging* / Q000601:surgery; D010673:Pheochromocytoma / Q000000981:diagnostic imaging* / Q000601:surgery; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D005462:Fluorine Radioisotopes; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; C043437:fluorodopa F 18; D019797:3-Iodobenzylguanidine; D004295:Dihydroxyphenylalanine