MALT lymphoma in children: a report from the NHL-BFM Study Group.

Marginal zone lymphomas of MALT type comprise a considerable group of indolent B-cell non-Hodgkin lymphoma (NHL) in adult patients. In childhood, however, these tumors are extremely rare, as nearly all pediatric patients have aggressive NHL. Among 2,703 children and adolescents registered into the prospective multicenter NHL-BFM treatment studies since 1986, only 4 patients (0.1%) displayed features of MALT lymphoma. These tumors were localized in the stomach, breast, lower lid, and conjunctiva, respectively and they were associated with H. pylori infection in two patients. All children are alive but long-term follow-up will be mandatory to assess the behavior of MALT lymphoma in this age group.