Clinical findings:
(1) multiple papulonodular skin lesions
(2) erosive symmetrical polyarthritis with progressive articular destruction
(3) variable involvement of mucosa and internal organs
For some patients MRH may occur as a paraneoplastic skin disorder.
Clinical course:
(1) The mean duration of disease activity is about 8 years.
(2) Disability associated with the polyarthritis may be significant.
Differential diagnosis:
(1) rheumatoid arthritis (RA)
Pathologic findings in a biopsy from a skin lesion or affected synovium:
(1) admixture of large mononuclear cells:and multinucleated giants cells
(2) cells have a PAS-positive ground glass cytoplasm with variable inclusions
(3) background of fibrous tissue
(4) variable lymphoplasmacytic infiltrate
Immunohistochemistry:
(1) vimentin positive
(2) mononuclear cells positive for Factor XIIIa
(3) multinucleated giant cells positive for CD68, lysozyme and HLA-DR.
