Lymph node involvement in chronic neutrophilic leukemia. An immunohistochemical study.

An immunohistochemical study was performed on autopsy material from a patient with chronic neutrophilic leukaemia (CNL) using antibodies against various cell lineage-related antigens. Proliferation of immature neutrophils with occasional clusters of erythroblasts and megakaryocytes were noted in the retroperitoneal lymph nodes, spleen, and kidneys as well as in the bone marrow. Predominance of immature neutrophils in the lymph nodes suggested the emergence of a blast crisis, although there was no increase of blasts in the peripheral blood. Since immature myeloid cells are difficult to distinguish from malignant lymphoid cells on tissue sections, we suggest that immunohistochemical identification of cell lineage-related molecules on these cells is necessary for the more accurate interpretation of lymph node lesions in myeloid neoplasms.