Primary cutaneous marginal zone lymphoma in children: a report of 3 cases and review of the literature.

: Primary cutaneous marginal zone lymphoma (PCMZL) is one of the most common cutaneous B-cell lymphomas. It affects mostly patients in their fourth decade and manifests with multifocal nodules mostly on the arms and upper trunk in more than half of the patients. PCMZL is, however, rare in children and adolescents, with only 20 cases reported in patients aged 20 and younger. The authors present 3 cases of PCMZL in teenagers. The patients were 2 girls aged 18 and 13 and a 17-year-old boy. Two patients presented with multiple lesions involving various anatomic sites, whereas in 1 patient, 2 small closely opposed papules on the abdomen were seen. Histopathologically, the characteristic appearance of PCMZL was found in 3 of 4 specimens, with nodular infiltrates composed of small lymphocytes in the interfollicular compartment, reactive germinal centers, and plasma cells in small clusters mainly at the periphery of the infiltrates, whereas 1 specimen showed a dense lymphocytic infiltrate with small granulomas. Clonality was demonstrated by monotypic immunoglobulin light chain expression and/or monoclonal rearrangement of the immunoglobulin heavy chain genes. No Borrelia burgdorferi was identified on serology or by polymerase chain reaction in any of the cases. Treatment included excision or administration of antibiotics with complete remission in all the 3 patients indicating that PCMZL in children and young adolescents follows the same indolent course with a tendency for recurrences, but excellent prognosis as in adults. The pertinent literature on PCZL in childhood and adolescence is reviewed.