Ki-1 lymphomas in children.

Three male children, ages 8, 11, and 14 at presentation, with the recently described Ki-1 lymphomas are reported. All three had lymph node involvement. The lymphoma was classified as immunoblastic in two children, and mixed small and large cell in the third child. In histologic terms, sinusoid, paracortical, and diffuse lymph node involvement by lymphoma was evident in each case. Both cases of immunoblastic lymphoma were T11+, T10+, T9+, HLA/Dr+, Tac+, Ki-1+, LCA+, and EMA+, while the lage neoplastic cells of the other case were T11+, Ki-1+, and LCA+. In all three cases DNA analysis of immunoglobulin heavy and light chain genes as well as T-cell receptor beta- and gamma-chain genes showed only germline patterns. The patients were treated with multi-agent chemotherapy. Two are in complete remission at 13 and 16 months, while the third failed to achieve remission and is alive with disease 12 months after a diagnosis had been established.