A Rare Case of Autoimmune Enteropathy After Thymectomy

Autoimmune enteropathy (AIE) is a rare cause of chronic diarrhea associated with autoantibodies and susceptibility to other autoimmune diseases, such as rheumatoid arthritis, diabetes, autoimmune hemolytic anemia, and atopic dermatitis. While it is more common in children, the prevalence of AIE in adults is increasing. Due to the nonspecific nature of its presenting symptoms and the lack of consistent findings, AIE can be challenging to diagnose. Here, we present a 66-year-old male patient who presented to the emergency department with diarrhea and recurrent bilateral pleural effusions two months after thymoma resection and was eventually diagnosed with AIE. The evaluation revealed blunting of small intestinal villi on biopsy, an IgG staining pattern indicative of circulating anti-enterocyte antibodies, as well as the presence of serum anti-enterocyte and anti-goblet cell antibodies, establishing the diagnosis of AIE.