Alkaline phosphatase positive lymphoma

Alkaline phosphatase (AP) activity on cryostat sections of the skin of 38 cases of non-Hodgkin's lymphomas of the B cell type and of 10 cases of lymphadenosis benigna cutis have been studied. Membrane-bound AP activity has been found in 8 out of 28 cases of low-grade malignant lymphomas of the B cell type and in 2 out of 10 cases of lymphadenosis benigna cutis. This is a known phenomenon in the latter. In the literature of non-Hodgkin's lymphoma AP activity is related to the intermediate type of lymphocytic lymphoma. Further studies are needed to demonstrate that the AP activity correlates with a specific cell type in the B lymphoid cell differentiation.