A Rare Case of Thymoma Associated Autoimmune Enteropathy

Abstract

Purpose: A 61-year-old female with history of bronchiectasis and resection of benign thymoma presented to The Mount Sinai Hospital with severe weight loss and malnutrition. She reported having chronic watery diarrhea and lower abdominal pain since 2004. A diagnosis of celiac disease was made based on an extensive work up at an outside hospital, which included abnormal small intestinal biopsies, but she had minimal clinical response to a gluten free diet. After a repeat colonoscopy 9 months later, Crohn's disease was diagnosed and she was treated with 4–5 courses of steroid tapering and 6-MP until February 2007, when she was hospitalized twice for severe constipation. On presentation to the Mount Sinai Hospital, she had persistent abdominal pain and reported weight loss of 45 lbs, despite continued gluten restricted diet. On examination, she appeared malnourished and had severe tenderness in left lower quadrant but no palpable mass. Lab data included Hb 10 g/dl, ESR 83, CRP 20.5, albumin 3.5 g/dl and negative HLA-DQ2/DQ8. Immunoglobulin quantitation and absolute T and B cell counts were within normal range. Small bowel series and abdomen CT were normal. On colonoscopy, the colon and terminal ileum appeared normal. Random colonic biopsies revealed loss of goblet cells and Paneth cells, presence of lymphocyte infiltrates in the lamina propria and and multiple apoptotic bodies. The findings were interpreted as autoimmune enteritis (AIE). Indirect immunofluorescence using patient's serum and frozen section of normal small bowel showed linear staining along the gut epithelium, consistent with anti-enterocyte antibodies. The patient resumed a gluten unrestricted diet and started oral prednisone and 6-MP. Her abdominal pain and diarrhea promptly improved and oral prednisone was successfully tapered over the next two months. Clinical remission of GI symptoms was maintained with 6-MP for over 1 year. Worsening bronchiectasis due to recurrent pseudomonas infections resulted in multiple hospitalization and the patient succumbed to respiratory failure in April, 2008. AIE was first described in 1982 by Unsworth and Walker-Smith and characterized by protracted diarrhea, circulating enterocyte antibody and associated autoimmune conditions. Only 3 of 30 reported cases had associated with thymoma. No standard approach for the treatment has not been established and immunosuppressive treatment is required in most cases. 60% of patients respond to steroid and 2/3 of steroid responders require additional immunomodulators for maintenance of remission. AIE should be considered in the differential diagnosis of malabsorption and refractory celiac disease.