title: A case of osteoarthropathy due to Erdheim-Chester disease with overlapping Langerhans' cell infiltration.
abstract: Histiocytosis sometimes involves the joints, and is one of the important differential diagnoses of osteoarthropathy. A 31-year-old man presented with recurrent fever and bilateral knee arthritis two years prior to admission. He also showed the hypopituitary mass lesion and partial hypopituitarism. X-ray studies showed both osteosclerotic and osteolytic lesions near the large joints. Histological findings of bone biopsy revealed foamy macrophage infiltration, which were CD68+CD1a-S100-, and Erdheim-Chester disease was diagnosed. In addition, CD68+CD1a+ Langerhans' cells also aggregated in the same lesions, and we thought this case was a rare variant of Erdheim-Chester disease with overlapping histiocytic invasion.
authors.affiliation: Department of Allergy and Rheumatology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Naruse
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Shoda
authors.forename: Akiko
authors.initials: A
authors.lastname: Okamoto
authors.forename: Teruaki
authors.initials: T
authors.lastname: Oka
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D031249:Erdheim-Chester Disease / Q000150:complications / Q000175:diagnosis*; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007801:Langerhans Cells / Q000473:pathology; D008297:Male; D010005:Osteoarthropathy, Secondary Hypertrophic / Q000150:complications / Q000175:diagnosis*