[IgM kappa immunocytoma in IgM-kappa monoclonal gammopathy]

A case of monoclonal gammopathy of the IgM kappa class is reported, in which a large number of reddish-brown, non-itching papules, reaching at maximum the size of peas and aligned in a follicular arrangement, had been seen to an unchanged extent on the left upper thigh for 6 years. Both histologically and immunohistologically, a B-cell lymphoma releasing kappa-type IgM was demonstrated. The clinical picture obtained was different from that of the few other cases reported in the literature, which have always involved either large-surface infiltrates or much larger nodes, either solitary or irregularly arranged.