Multicentric reticulohistiocytosis. A report of 3 cases and review of literature.

Multicentric reticulohistiocytosis (MR) is a rare systemic disease of unknown cause. The disease is characterized by tissue infiltration of lipid-laden histiocytes and multinucleated giant cells. Destructive polyarthritis and skin lesions are the most common findings. The disease becomes apparent in adult life. We report on 3 patients and discuss the specific radiographic characteristics of bone and joint involvement. The radiologic feature is a bilateral, symmetric joint involvement with predilection for the interphalangeal and metacarpophalangeal joints. In all of our cases we found an early involvement of shoulder joints. Erosive arthritis begins at the margins of the joints, progressing to osseous defects and to severe joint destruction. In contrast to rheumatoid arthritis, periarticular osteoporosis and early joint space loss are absent in MR. In addition, significant erosions of distal interphalangeal joints are not common in rheumatoid arthritis.