Strongyloides stercoralis Hyperinfection Syndrome Presenting as Severe, Recurrent Gastrointestinal Bleeding, Leading to a Diagnosis of Cushing Disease.

A 50-year-old male immigrant from Ethiopia presented for consultation after 3 years of hematochezia/melena requiring > 25 units of blood transfusions. Physical examination revealed severe proximal muscle wasting and weakness, central obesity, proptosis, and abdominal striae, accompanied by eosinophilia, elevated hemoglobin A1c, elevated 24-hour urinary cortisol, lack of suppression of 8 am cortisol levels by 1 mg dexamethasone, and inappropriately elevated random adrenocorticotropic hormone (ACTH) level. Histopathological examination of gastrointestinal biopsies showed large numbers of Strongyloides stercoralis, indicating Strongyloides hyperinfection. Treatment with 2 days of ivermectin led to resolution of gastrointestinal bleeding. This syndrome was due to chronic immunosuppression from a pituitary ACTH (corticotroph) microadenoma, of which resection led to gradual normalization of urine cortisol, improved glycemic control, resolution of eosinophilia, and no recurrence of infection.