A 4-year-old boy was referred for evaluation of hepatosplenomegaly. He was diagnosed at age 4months with Weber-Christian syndrome after presenting with panniculitis and fever. He had increasing abdominal girth and hepatosplenomegaly, symmetric large joint synovitis, chronic truncal and facial scaling dermatitis, and failure to thrive for 1 year before evaluation. He had occasional flares of fever, rash, and arthritis, which were treated using nonsteroidal antiinflammatory agents. Physical examination showed a chronically ill child with a height and weight in lower than the fifth percentile. He had obvious hepatosplenomegaly, multiple large joint effusions with elbow contractures, and an erythematous scaling rash on his trunk and scalp. Chest radiography showed hilar fullness. Laboratory evaluation showed the following: white blood count: 7,800/mm3; hemoglobin concentration: 9.2 g/dL; mean corpuscular volume: 64 fl; hematocrit concentration: 28%; erythrocyte sedimentation rate: 6 mm/hr, C-reactive protein concentration: 2.5 mg/dL; aspartate aminotransferase concentration: 80 U/L; alanine aminotransferase concentration: 42 U/L; prothrombin time: 12.7 seconds; and partial thromboplastin time: 32 seconds. Serum glucose, electrolytes, blood urea nitrogen, and creatinine concentrations were within normal ranges. Serology results for Epstein-Barr virus, cytomegalovirus, and syphilis were negative. Abdominal ultrasound showed marked lymphadenopathy in the porta hepatis and mesentery, hepatosplenomegaly, and normal portal blood flow. Percutaneous liver biopsy was performed (Fig. 1 and 2).FIG. 1. No caption available.FIG. 2. No caption available.What is your diagnosis? A. Tuberculosis B. Berylliosis C. Infectious mononucleosis D. Sarcoidosis E. Histoplasmosis Answer: The percutaneous liver biopsy showed noncaseating granulomas with multinucleated giant cells. Inclusions, consistent with Schaumann bodies were seen, as depicted in Figure 2. These are highly supportive, though not definitely diagnostic, of sarcoidosis. A skin biopsy specimen also contained noncaseating granulomas with multinucleated giant cells and similar inclusions. Additional findings included mediastinal and hilar adenopathy seen on the chest computed tomography scan, hypercalciuria, and an increased angiotensin-converting enzyme level at 153 IU/L (normal, 10–34 IU/L). Results of ophthalmologic examination were normal. He was diagnosed with sarcoidosis and treated with corticosteroids. His rash and hepatosplenomegaly resolved within 1 month of treatment, and his polysynovitis is slowly improving. Comment: Sarcoidosis is a chronic, multisystem, granulomatous disease of unknown etiology. It is uncommon in children, with different clinical syndromes depending on the age at presentation. Preschool children tend to have arthritis, dermatitis, and uveitis, whereas, school-age children and adolescents more commonly present with lymphadenopathy, pulmonary disease, and generalized symptoms (1). Diagnosis is suspected on clinical grounds, supported by laboratory studies and confirmed by the demonstration of the noncaseating granulomas, ideally in more than one tissue site. The inability to show an infectious cause by special stains, culture, or serology, and improvement with corticosteroids further supports the diagnosis. Hepatomegaly is present 25 to 40% of the time, and granulomas are found in approximately 80% of liver biopsy specimens in children with sarcoidosis (2). The liver is most often an innocent bystander, becoming enlarged and developing mild cholestasis secondary to the infiltration with granulomas. Intrahepatic cholestasis, hepatic failure, portal hypertension, and Budd Chiari syndrome have been reported in adult patients. In a recent review of 100 adult patients with sarcoidosis who underwent liver biopsy, 100% had intrahepatic granulomas. Various other histologic changes have been reported, including cholestasis (58%), necroinflammatory changes (41%), and vascular abnormalities with sinusoidal dilatation and nodular regenerative hyperplasia (20%). Fibrosis was present in 21% of the biopsy specimens and cirrhosis was present in 6%(3).