Extranodal marginal zone B-cell lymphoma/maltoma of the lip in a child: case report and review of cutaneous lymphoid proliferations in childhood.

All forms of cutaneous lymphomas are rare in children. Extranodal marginal zone B-cell lymphomas (EMZBL)/mucosa-associated lymphoid tissue (MALT) lymphomas are unusual neoplasms in children and young adults. We report a case of an EMZBL/MALT lymphoma of the lip in a previously healthy 14-year-old boy without immunodeficiency, confirmed by immunohistochemistry and documentation of clonal rearrangement of the immunoglobulin heavy-chain gene. Additionally, we present a review of the differential diagnosis of skin and mucosal lymphoid proliferations in childhood.