Intravascular histiocytosis is an unusual cutaneous lesion with massive aggregates mainly composed of histiocytes in markedly dilated dermal vessel and previously reported in associations with rheumatoid arthritis (RA). We report a case of intravascular histiocytosis in RA patient. A 58-year-old woman having 20-year history of RA presented with the right elbow pain and poorly demarcated, indurated erythema in the right forearm. Biopsy revealed vascular proliferation and mononuclear cellular aggregates in the dilated vessels of dermis. Immunohistochemical findings of the intravascular cells were consistent with a histiocytic differentiation. She underwent synovectomy in the right elbow joint and had rapid resolution of cutaneous lesion.

Keywords: Intravascular histiocytosis, Rheumatoid arthritis