Cushing's syndrome due to ovarian serous adenocarcinoma secreting multiple endocrine substances: a case report and immunohistochemical analysis.

Background: Although Cushing's syndrome arises from various neuroendocrine tumors secreting adrenocorticotropin (ACTH) ectopically, ovarian carcinoma rarely causes this syndrome.
Case: A 66-year-old woman presented with facial swelling and skin pigmentation. She manifested hypercortisolemia, high plasma ACTH, and lack of dexamethasone suppression. MRI showed a solid ovarian tumor and resection of the tumor led to normalization of ACTH and cortisol levels. In addition, elevated serum vasopressin (ADH) and alpha-fetoprotein (AFP) were found, which were also normalized after removal of tumors. Pathological diagnosis was serous adenocarcinoma with neuroendocrine and hepatoid features. Immunohistochemistry detected immunoreactivity of chromogranin A, ACTH, ADH, and AFP in tumor cells.
Conclusion: This is a very rare case of successful treatment of Cushing's syndrome arising from an ovarian adenocarcinoma secreting multiple endocrine substances.