Endocrine Abstracts

JOINT3910

Background: Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy that typically arises in the adrenal glands. Its occurrence in ectopic adrenal tissue is exceptionally rare, posing significant diagnostic and therapeutic challenges.

Case Presentation and Literature Review: We describe the case of a 71-year-old female presenting with severe Cushing’s syndrome and extreme hypercortisolism (17, 000 nmol/l; normal range: 166-507 nmol/l). Imaging revealed normal adrenal glands but extensive peritoneal carcinomatosis with a peritoneal mass at the hepatic hilum. An FDG-PET scan revealed intensely hypermetabolic peritoneal foci diffusely distributed, including perihepatic regions (SUVmax 18. 5 in the posterior-superior area), Hormonal assays confirmed ACTH-independent cortisol hypersecretion (ACTH <0. 84 pmol/l; normal range: 1-10. 75 pmol/l), along with markedly elevated levels of 11-deoxycorticosterone (DOC) (14, 177 pmol/l; normal range: 30-400 pmol/l), other steroid hormone precursors, and androgens (Testosterone: 18. 23 nmol/l; normal range: 0. 16-1. 11). Peritoneal histopathological examination and immunohistochemistry, with positive expression of synaptophysin, SF1 and inhibin A, established the diagnosis of high-grade ectopic ACC. Despite optimal medical therapy with osilodrostat and metyrapone, cortisol secretion remained uncontrolled, and the patient’s condition deteriorated rapidly, leading to fatal complications. We reviewed 16 previously reported cases and found our case to be unique due to its location and the extreme steroid levels.

Conclusion: This case underscores the exceptional presentation of a functional ACC arising in adrenal rest tissue in the peritoneum leading to a severe Cushing syndrome producing extremely high levels of cortisol, DOC, and androgens. Such an occurrence is unparalleled in the literature.