Alkaline phosphatase positive lymphomas: a morphologic, immunologic, and enzymehistochemical study.

Among 87 cases of different non-Hodgkin lymphomas studied with morphologic, enzymehistochemical, and immunologic techniques, ten were found with a positive alkaline phosphatase staining reaction of the cell membranes. The ages of the seven adult patients included in this report varied between 48-85 years. Studies of cell suspensions or cryostat sections demonstrated the presence of monoclonal membrane immunoglobulins indicating a B-cell origin of these lymphomas. Investigation of peripheral blood of six patients revealed the presence of a corresponding monoclonal lymphocyte population in four. According to Rappaport's classification, lymphoblastic, poorly differentiated, and well-differentiated lymphocytic as well as histiocytic lymphoma were encountered. According to the "Kiel" classification, most lymphomas were classified in the group of follicle-center cell tumors. The clinical course of the patients was variable. Non-Hodgkin lymphomas with alkaline phosphatase positive staining do not constitute a separate entity.