Immunoblastic lymphadenopathy is a recently described lymphoproliferative disorder, presumably of B-cell origin. It is characterized by regional or generalized lymphadenopathy, usually associated with hypergammaglobulinemia or dysproteinemia. Other findings may be hepatosplenomegaly, dermatitis, fever, malaise, weight loss, and various altered immunologic reactions. Histologically, the involved lymph nodes show immunoblast, plasmacytoid, and plasma cell proliferation. This may be extranodal as well. The case reported here is one of the few followed up prospectively. The patient's purpuric eruption was an apparent manifestation of a type II mixed cryoglobulinemia. Differing from what has usually been reported, we noted hypogammaglobulinemia and findings in part of altered cell-mediated immunity. Despite leukopenia and anemia there were no infectious episodes. Although a satisfactory treatment regimen has not been established, there was beneficial response to prednisone and short courses of melphalan.