title: Intravascular or intralymphatic histiocytosis associated with rheumatoid arthritis: a report of 4 cases.
abstract: BACKGROUND
  Various skin lesions occur in association with rheumatoid arthritis (RA).
  
  
  METHODS
  We report a distinctive skin lesion observed in 4 patients with RA. All patients had RA for many years and developed asymptomatic, irregularly shaped erythema over the swollen elbow joints and the nearby part of the forearm. Histopathologically, all cases showed massive aggregates mainly composed of histiocytes in markedly dilated vessels in the dermis, accompanied by a dermal infiltrate of lymphocytes, plasma cells, neutrophils, or a combination of these. A total of 9 cases, including ours, showing similar histopathologic findings have been reported in the literature, of which 7 were associated with RA and presented relatively common clinical appearance.
  
  
  CONCLUSIONS
  In spite of some disagreement as to whether the dilated vessels are blood vessels or lymphatics, it is most likely that these 7 cases belong to the same clinical entity closely associated with RA.
authors.affiliation: Department of Dermatology, The University of Tokushima School of Medicine, Japan. takiwaki@clin.med.tokushima-u.ac.jp
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Takiwaki
authors.forename: Atsuko
authors.initials: A
authors.lastname: Adachi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kohno
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications*; D001808:Blood Vessels / Q000473:pathology; D005260:Female; D006644:Histiocytes / Q000473:pathology; D015614:Histiocytosis / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008208:Lymphatic System / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000098:blood supply / Q000737:chemistry / Q000473:pathology; D017445:Skin Diseases, Vascular / Q000150:complications* / Q000378:metabolism / Q000473:pathology