Selective IgM deficiency in CD30+ cutaneous lymphoproliferative disorder.

Primary cutaneous anaplastic large cell lymphoma with local lymph node involvement was diagnosed in a 13-year-old boy with an ulcerative facial lesion and a history of skin lesions of lymphomatoid papulosis. The tumor regressed with chemotherapy. He continued to develop recurrent self-limited lesions of lymphomatoid papulosis , with a halo surrounding these lesions during the healing phase. He developed selective immunoglobulin M deficiency with decline in levels even 4 years after the chemotherapy with no recurrent infections noted and adequate IgG response to immunizations. Both peripheral blood IgM+ and memory B cells were low, suggesting a possible cause-effect relationship between selective immunoglobulin M deficiency and chronic CD30+ cutaneous lymphoproliferative disorders.