A 63-year-old male patient spontaneously developed severe erosive orogenital mucositis, palmoplantar and gluteal inflammatory lesions resistant to therapy. The skin lesions clinically and histologically resembled lichen-planus-like graft-versus-host disease. Investigation for an underlying autoimmune or malignant disorder revealed a centrocytic-centroblastic low-grade non-Hodgkin’s lymphoma (according to the Kiel classification) in the bone marrow, mesenterial and iliacal lymphoma. Serological titers were intermittently positive for ANA, anti-Sm/U1RNP, anti-Ro and anti-dsDNA. Immunoprecipitation of lysates from radiolabeled human keratinocytes with the patient’s serum revealed circulating antibodies against 210-kD (desmoplakin II), 190- and 170-kD antigens but none against the 230-kD antigen or 250-kD desmoplakin I. Under cytostatic chemotherapy the lymphomas showed complete and long-lasting remission, whereas the mucocutaneous lesions persisted. Six years after diagnosis, the mucocutaneous lesions are sufficiently controlled by immunosuppressive therapy. In the presented case, several features of lymphoma-associated dysimmunoreactivity are assumed that bring about the intrinsic production of various autoantibodies typical of paraneoplastic pemphigus and systemic lupus erythematosus.