[Cytochemical study of alkaline phosphatase activity as a cancer cell marker in exudates from serous-membrane lined...

Cytochemical demonstration of levamisole-sensitive alkaline phosphatase (AP) have been used for the identification of tumor cells in serous effusions. AP-activity is not demonstrable in mesothelial cells and histiocytes-macrophages in serous effusions in 18 noncancer patients. Enzyme activity is detected in cancer cells in serous effusions in 19 from 52 cancer patients. Oncoassociated antigens are detected on the membranes of AP-positive cancer cells more rare that AP-negative cancer cells.