Kaposi sarcoma related to an ectopic hypothalamic adrenocorticotropic hormone-secreting adenoma: case report

We aim to report a case of Kaposi sarcoma (KS) with Cushing's syndrome caused by endogenic glucocorticoid-induced immunosuppression.

A 43-year-old woman presented with delirium, hirsutism, fatigue, and hypertension. At the time of presentation, physical findings showed a Cushingoid appearance, with moon-like facies, hirsutism, and hyperpigmentation. Laboratory findings showed the following: adrenocorticotropic hormone, 86.7 pg/mL (normal range, 0-46 pg/mL); baseline cortisol level, 50 microg/dL (normal range, 6.2-19 microg/dL); potassium, 2.2 mEq/L (normal range, 3.5-5 mEq/L); and midnight cortisol level, 33 microg/dL. Serum cortisol levels failed to suppress after low and high doses of dexamethasone; these findings confirmed the diagnosis of ectopic adrenocorticotropic hormone production. Magnetic resonance imaging revealed a 12 x 15-mm, round, hypothalamic mass lesion in the center of the median eminence.

Endoscopic biopsy from the floor of the third ventricle was performed, and pathological examination of the lesion showed a diffuse adrenocorticotropic hormone-secreting adenoma. The patient developed diffuse skin lesions that were proven to be a KS by skin biopsy while she was prepared for transcranial surgery. After surgical removal of the adenoma, she became hypocortisolemic and required cortisol replacement. Within 1 month after surgery, all KS lesions disappeared spontaneously.

Excessive cortisol may induce immunosuppression. KS is one of the most common malignant tumors of patients with immunosuppression. To the best of our knowledge, this is the first case of Cushing's syndrome with KS caused by endogenous glucocorticoid-induced immunosuppression.