Hepatic Langerhans Cell Histiocytosis (LCH) Presenting as a Harbinger of Multisystem LCH.

Langerhans cell histiocytosis (LCH) is a rare systemic disorder characterized by an infiltration of CD1a+/langerin+ histiocytes, commonly involving bone, skin, and lymph nodes in children. Hepatic involvement is rarely observed in multisystem LCH. We describe an exceptional case of hepatic LCH in an adult preceding the diagnosis of multisystem LCH, mimicking anti-mitochondrial antibody (AMA)-negative primary biliary cholangitis (PBC). A 65-year-old man presented with intermittent pruritus, weakness, dyspnea, fever, and chills that have been progressive for four years. Physical examination was unremarkable. Laboratory work revealed cholestatic biochemistry profile. Liver biopsy showed portal non-necrotizing granuloma encasing a damaged duct (florid duct lesion), and multifocal lobular Kupffer cell clusters, suggestive of PBC. Tests for autoimmune diseases including AMA were negative. Endoscopic retrograde cholangiopancreatography (ERCP) was negative for biliary obstruction. One month after the liver biopsy, he developed flaky, red, and burning rash on the right scalp, forehead, and epigastric skin. A skin biopsy at an outside institution revealed LCH. Subsequent re-examination of the liver biopsy showed that the histiocytes within the florid duct lesion were positive for CD1a and S-100. Concurrently, a small focus of LCH was noted in his gastric biopsy performed for gastritis symptoms. Hepatic LCH may mimic AMA-negative PBC histologically and clinically and may present as a harbinger of multisystem LCH. While rendering the diagnosis would be challenging without prior history of LCH and with focal involvement, awareness of such presentation and communication with clinical colleagues may be helpful.