2256 A Unique Case of Concurrent Langerhans Cell Histiocytosis and Autoimmune Hepatitis Complicated by a Lower Gastrointestinal Bleed

Abstract

INTRODUCTION: Autoimmune hepatitis (AIH) and Langerhans Cell Histiocytosis (LCH) are two independently rare disease processes that can have similar presentations. There have been no documented cases of concurrent AIH and LCH. We illustrate a complex case that required an interdisciplinary approach to ultimately diagnose and treat the patient. This unique presentation contributes to the medical literature of the two rare diseases. CASE DESCRIPTION/METHODS: 20-year-old male with no significant history presented with worsening jaundice, diffuse, pruritic rash, and abdominal pain over one month. On admission, the patient’s labs showed significantly elevated liver function tests (LFTs), eosinophilia, and anemia. Exam was notable for diffuse lymphadenopathy (LAD), hepatosplenomegaly, and a diffuse, non-blanching, morbilliform rash. Interdisciplinary workup was notable for positive anti smooth muscle antibody (ASMA), and anti-neutrophilic antibody (ANA). A liver biopsy was done and showed findings of severe inflammation with interface activity, consistent with AIH. A lymph node (LN) biopsy showed findings consistent with LCH, including histiocyte clusters (HC). He was started on high dose steroids with LAD/LFT improvement; yet, his hospital stay was complicated by a gastrointestinal (GI) bleed requiring a hemicolectomy. The patient was ultimately transferred to a larger referral center where he continued to improve with steroids and was ultimately discharged with close follow up. DISCUSSION: LCH tends to affect skin or bones; however, LN and GI involvement are relatively uncommon. This case was notable for a LN biopsy showing HC with reniform nuclei, nuclear grooves and eosinophils with immunohistochemical stains positive for S-100, CD1a, fascin, langerin, CD45, and CD68, consistent with LCH. The resected colon showed atypical histiocyte proliferation positive for fascin, CD4, and CD68. Key findings can help support a diagnosis of AIH, such as elevated LFTs, ASMA, and ANA, as well as a liver biopsy showing inflammation with interface activity, eosinophils, plasma cells, and characteristic fibrosis, all of which were found in this patient. In either case, steroids were indicated and ultimately helped the patient clinically improve. Such a case is distinct since the LCH appeared to be a systemic process, with findings of diffuse LAD, questionable GI involvement, and no liver involvement, but rather concurrent AIH. This case was further notable for a complication of a lower GI bleed requiring a hemicolectomy.