Erdheim-chester disease.

Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis of unknown etiology, characterized by multi-organ involvement. ECD is usually diagnosed on the basis of characteristic radiologic and histopathological findings. Lesions may be skeletal and/or extraskeletal in location, and may include the skin, lung, heart, and central nervous system. We describe here a 68-year-old man with multiple yellowish plaques and a pinkish nodule on his face and scalp. He had been previously diagnosed with diabetes insipidus, and recently complained of coughing and dyspnea. Imaging studies showed multiple osteosclerotic lesions of the bones, a moderate amount of pericardial effusion, and multifocal infiltrative lesions in the perirenal space. Histopathological examination of the skin lesions revealed dermal infiltration of foamy histiocytes with multinuclear giant cells. Moreover, laparoscopic biopsy of the perirenal tissue revealed fibrosis with infiltrating foamy histiocytes being CD68-positive and S100-negative. Based on these findings, he was diagnosed with ECD with extraskeletal manifestations, and treated with interferon-alpha.