Ectopic Cushing's syndrome caused by an esthesioneuroblastoma.

Objective: To report a case of florid Cushing's hormone (ACTH) secretion related to the presence of an esthesioneuroblastoma (ENB).

Methods: We present clinical, laboratory, and pathologic findings in a 36-year-old Caucasian man presenting with Cushing's syndrome. Results of computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) scanning, and somatostatin receptor scintigraphy are presented, along with tumor pathology findings.

Results: After initial biochemical studies suggestive of ectopic Cushing's syndrome, CT of the chest and abdomen revealed multiple cavitated pulmonary lesions, an ischiorectal mass, and bilateral adrenal hyperplasia. MRI of the pituitary gland revealed normal findings. Both PET scanning with [18 F]-flurodeoxyglucose (FDG) and somatostatin receptor scintigraphy with 111 indium-penetetreotide (Octreoscan) revealed strong tracer uptake in the ethmoid region. CT and MRI of the sinuses and brain subsequently localized a 5-cm mass in the ethmoid sinuses with intracranial extension. On biopsy, pathology results were consistent with a diagnosis of ENB, and immunohistochemical analysis revealed that tumor cells were strongly positive for ACTH, synaptophysin, and S-100, providing definitive diagnosis of ACTH-producing ENB. Hypercortisolemia was initially controlled by metyrapone, then by external beam radiation therapy (RT).

Conclusion: This case illustrates the usefulness of nuclear imaging in the diagnosis of ENB, and the importance of prompt control of hypercortisolemia in Cushing's syndrome.