Reactive hemophagocytosis in Ki-l positive large cell lymphoma: a case study.

: A case of large cell lymphoma presenting with hemophagocytic syndrome is reported. The clinicopathological findings suggested a diagnosis of malignant histiocytosis, but on the basis of immunohistological studies Ki-l lymphoma was diagnosed. Neoplastic cells expressed activation antigens such as HLA-DR, IL 2R, T10 and Ki-l, and showed high proliferative activity, but were devoid of T and B cell markers. The high percentage of reactive macrophages found in the bone marrow and lymph node probably reflected the release of lymphokines by the tumor population. The patient was treated with aggressive chemotherapy and is in complete remission at 8 months from diagnosis.