Immunologic and cytochemical properties of histiocytic and mixed histiocytic-lymphocytic lymphomas.

Lymph nodes were biopsied from seven patients with the presumptive clinical diagnosis of lymphoma and studied for their ability to form spontaneous rosettes with sheep erythrocytes (T cell marker), for surface immunoglobulins (B cell marker), for cytochemical reactivity with peroxidase, alpha-naphthyl acetate and butyrate esterases, naphthol ASD chloroacetate esterase, acid phosphatase, periodic acid-Schiff, Sudan black B, and Wright-Giemsa on touch preparations, as well as in hematoxylin and eosin-stained sections. Lymph nodes from patients without hematologic malignancy served as control. Diagnoses of diffuse histiocytic lymphoma were made in five cases and diffuse mixed histiocytic-lymphocytic lymphoma in 2 cases. The cytochemical staining of the lymphoma cells were typical of lymphoid cells rather than macrophages. In five cases neoplastic cells contained surface immunoglobulins, suggesting a B cell origin, and in one case a paucity of cell surface markers was found. Cells from uninvolved nodes of lymphoma patients could not be differentiated from those of the control group.