Ovarian Adrenal Rest Tumor in a Congenital Adrenal Hyperplasia Patient with Adrenocorticotropin Hypersecretion following Adrenalectomy

<i>Objective:</i> Ovarian adrenal rest tumors (OARTs) are rare in contrast to testicular adrenal rest tumors. We report a case of OART in a patient with congenital adrenal hyperplasia who developed Nelson’s syndrome after bilateral adrenalectomy. <i>Methods:</i> We describe the clinical, imaging, and laboratory findings of the patient and review the relevant literature regarding OART and the possible interaction between ACTH and brown adipose tissue. <i>Results:</i> An 18-year-old female with congenital adrenal hyperplasia, who had undergone bilateral adrenalectomy at the age of 10 years, presented with severe hyperpigmentation and hirsutism. Rectal ultrasonography showed a mass in the right ovary. ¹⁸F-fluorodeoxyglucose PET/CT revealed intense uptake both in this mass and in brown adipose tissue located in typical supradiaphragmatic sites. Laparoscopic removal of the ovarian mass confirmed the diagnosis of OART. A systematic review revealed 9 documented cases of OART. As in our case, all presented with elevated ACTH levels. <i>Conclusions:</i> Common to all documented cases of OART are sustained high ACTH levels that activate the adrenal anlagen tissue in the ovaries.