Erdheim-Chester disease A case report

A 42-year-old man with Erdheim-Chester disease (EC) is presented. This is t he first case of this disease reported in Korea. The patient complained of knee pain and plain roentgenogram of the bilateral legs revealed diffusely increased density, coarsened trabecular pattern, and cortical thickening in the diaphysis, and metaphysis as well as epiphysis. Magnetic resonance ima ging revealed that the lesions showed low signal intensity on T1-weighted i mages and heterogeneously low and high signal intensity on T2-weighted imag es. Histological examination of the biopsy specimen showed a xanthogranulom atous lesion consisting aggregations of foamy histiocytes and Touton-type g iant cells. Immunohistochemical staining showed positive reaction to anti-S -100 and lysozyme in the cytoplasm of the giant cells.