Ectopic Adrenocorticotropic Hormone Syndrome Secondary to Undifferentiated Pleomorphic Sarcoma of the Thigh: A Rare Paraneoplastic Manifestation

Undifferentiated pleomorphic sarcoma (UPS) is a rare, high-grade soft tissue sarcoma. Ectopic adrenocorticotropic hormone (ACTH) syndrome is an uncommon paraneoplastic phenomenon and is most frequently associated with neuroendocrine tumors. Herein, we present a unique case of a 55-year-old woman diagnosed with UPS of the left thigh, complicated by paraneoplastic ectopic ACTH syndrome. To our knowledge, this is the first reported case of ectopic ACTH syndrome associated with UPS in the adult population.