Demonstration of coexistent B-cell lymphoma and therapy-related acute myelogenous leukemia in lymph nodes by flow cytometry and immunohistochemistry. Case report and review of the literature.

A 58-yr-old white woman, with a 9-yr history of non-Hodgkin's lymphoma with recurrences and multi-modality therapy, presents with acute leukemia and residual lymphadenopathy. By flow cytometric analysis, cytochemistry, and cytomorphology, the leukemia is classified as acute myelogenous leukemia (AML), M4, and the lymph nodes are found to contain residual NHL in addition to an AML infiltrate. Immunohistochemistry performed on the lymph nodes correlates with the flow cytometric data. A review of the literature of AML secondary to therapy for non-Hodgkin's lymphoma is also conducted. There are no documented cases in the English literature of simultaneous involvement of lymph nodes by residual lymphoma and an AML infiltrate. Thus, this report is unique in the simultaneous involvement of lymph nodes by residual lymphoma and therapy-related AML. It emphasizes the application and usefulness of flow cytometry and immunohistochemistry in such cases.