Polyarthritis, mononeuritis multiplex and eczematous ulcerative skin rash in a patient with myelodysplastic syndrome and peripheral large granular lymphocytosis.

A patient with polyarthritis, peripheral mononeuritis multiplex with spatial and temporal fluctuation, and eczematous, ulcerative skin rash in the lower extremities was found to have myelodysplastic syndrome (MDS) in the bone marrow and concomitant large granular lymphocytosis in the peripheral blood. Histochemical study showed that cells with large granular lymphocyte markers (CD2+, 11b+, 16+, 57+, HLA-DR+) had infiltrated into the skin and around the nerve fibers. Both the bone marrow dyscrasia and rheumatic manifestations of this patient improved significantly after prednisolone therapy. The unusual rheumatologic manifestations of this patient appear to derive from a delicate balance between MDS and large granular lymphocytosis.