PAT-5. Langerhans cell histiocytosis in liver: single organ involvement in a child.

Langerhans cell histiocytosis (LCH; Histiocytosis X) is a rare neoplastic process that can affect various organ systems. The hepatic manifestation in LCH is rare and usually presents as part of a disseminated, multi-system process. We report a case of LCH involving only the liver. A 9-year-old African-American girl was admitted with abdominal pain, vomiting, fever and fatigue. On physical examination the patient had scleral icterus and massive hepatomegaly; no ascites or splenomegaly. The laboratory tests revealed moderate liver dysfunction. Hepatitis serology and skin test for TB were negative. No skeletal abnormalities or skin lesions were seen. A CT scan showed large, hypodense lesions in the right lobe of the liver. The chest x-ray and CT were normal. Past medical history was unremarkable. The liver needle biopsy revealed diffuse sinusoidal and portal histiocytic infiltration, the histiocytes in areas forming non-caseating granulomatoid aggregates. In areas active bile duct infiltration and destruction by Langerhans cells was observed. Lymphocytes, eosinophils and neutrophils were seen admixed with the histiocytes. Most of the histiocytes had elongated nuclei with central folding or indentation and a small nucleolus. Neither cellular atypia, nor mitotic figures were seen. Extensive bile duct injury and ductular proliferation reminiscent of sclerosing cholangitis was seen. In some foci bridging necrosis was seen. The histiocytes expressed strong immunoreactivity to immunohistochemical stains S-100 protein and CD1a, diagnostic of Langerhans cell histiocytosis. Special stains for acid fast bacilli and fungal organisms were negative. The bilateral bone marrow biopsies were negative. The treatment of hepatic LCH consists of systemic chemotherapy, but the therapy is not effective once cirrhosis develops. In these cases, liver transplantation is an option. Our patient did not have cirrhosis and is doing well 3 months after the initiation of chemotherapy.

Natalia Buza, MD, and Salima Haque, MD. Tulane University Health Sciences Center, Department of Pathology New Orleans, LA. National Institute of Oncology, Department of Pathology, Budapest, Hungary.