AUTHOR=Chang Johnny Yau Cheung , Woo Chariene Shao Lin , Chow Wing Sun , White Anne , Wong Ka Chung , Tsui Po , Lee Alan Chun Hong , Leung Eunice Ka Hong , Woo Yu Cho , Tan Kathryn Choon Beng , Lam Karen Siu Ling , Lee Chi Ho , Lui David Tak Wai 

TITLE=Cushing’s syndrome caused by ACTH precursors secreted from a pancreatic yolk sac tumor in an adult—a case report and literature review

JOURNAL=Frontiers in Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1246796

DOI=10.3389/fmed.2023.1246796

ISSN=2296-858X

ABSTRACT=Here we report the first adult case of pancreatic yolk sac tumor with ectopic adrenocorticotropic hormone (ACTH) syndrome. The patient was a 27-year-old woman presenting with abdominal distension, Cushingoid features, and hyperpigmentation. Endogenous Cushing's syndrome was biochemically confirmed. ACTH level was in the normal range which raised the suspicion of ACTH precursor-dependent disease. Elevated ACTH precursors were detected, supporting the diagnosis of ectopic ACTH syndrome. Functional imaging followed by tissue sampling revealed a pancreatic yolk sac tumor. The final diagnosis was Cushing's syndrome due to a yolk sac tumor. The patient received a steroidogenesis inhibitor and subsequently bilateral adrenalectomy for control of hypercortisolism. Her yolk sac tumor was treated with chemotherapy and targeted therapy. Cushing's syndrome secondary to a yolk sac tumor is extremely rare. This case illustrated the utility of ACTH precursors measurement in confirming an ACTH-related pathology and distinguishing an ectopic from a pituitary source for Cushing's syndrome.