Case of multiple endocrine neoplasia 2B with probable ectopic adrenocorticotropic hormone-secreting liver metastasis from medullary thyroid carcinoma.

A 31 year old woman was diagnosed with multiple endocrine neoplasia (MEN) 2B at 10 years old. Dark pigmentation gradually developed on her skin and her serum adrenocorticotropic hormone (ACTH) was high, suggesting concurrent ectopic ACTH syndrome (EAS). Corticotropin-releasing hormone (CRH) loading test ruled out Cushing's disease and supported the diagnosis of EAS. Multiple low attenuation mass in the liver was observed in a computed tomography (CT) scan, and was suspected as ectopic ACTH-secreting metastatic tumor from medullary thyroid carcinoma (MTC). ACTH production by MTC is relatively rare, particularly in patients with MEN; patients with ectopic ACTH-secreting liver metastatic tumor from MTC in MEN 2B have never been reported previously.