[The significance of the cytochemical adenosine triphosphatase reaction for the diagnosis of benign monoclonal gammopathy (author's transl)].

In 26 cases with benign monoclonal gammopathy the cytochemical activity of the adenosintriphosphatase (ATPase) in the plasmocytes of bone marrow smears was studied. 15 cases showed a decreased and 11 patients showed normal proportions of ATPase positive cells, indicating that the impairment of ATP-ase is non-specific for the diagnosis of multiple myeloma.