Mg2+-dependent adenosine triphosphatase as an enzyme histochemical marker for the lymphomas of B-cell origin

Twenty-nine cases of malignant lymphoma were studied by the enzyme histochemical method and membrane surface markers. Strong adenosine triphosphatase (ATPase) activity was demonstrated in 15 cases of 20 B lymphomas and in one case of null-cell lymphoma (1/1) by a light- and electron-microscopic enzyme histochemical method according to Wachstein et al. Neoplastic cells in nodules of 2 nodular lymphomas (0/2) and in 8 cases of T lymphomas (0/8) did not show any ATPase activity enzyme-histochemically. The ATPase activity of B lymphomas was electron-microscopically demonstrated on the plasma membrane of lymphoma cells but not in the cytoplasmic organelles. The specificity of ATPase activity in B lymphomas was also examined enzyme-histochemically with reference to normal lymphoid tissues. Such specificity was similar to that of non-neoplastic B lymphocytes of primary follicles and the mantle zone of secondary follicles in lymphoid tissues. Therefore, ATPase is one of the useful enzyme histochemical markers in differentiating T and B subclasses of malignant lymphomas.