Abstract
Acid and alkaline phosphatases, esterases, and beta-glucuronidase were studied histochemically in the colon of a patient with familial polyposis in whom malignant changes had occurred. The acid hydrolases were found to be localized mainly in the supranuclear region of the cells of the epithelium of the normal mucosa. In the polyp epithelium these enzymes were found mainly in the basal areas of the epithelium at the junction between the latter and the lamina propria. In the cancer cells enzyme activity was decreased and distributed randomly. Alkaline phosphatase was present only in the capillaries in the normal and the polypmucosa. In the cancer tissue this enzyme was found in the capillaries, the smooth muscle cells, and the invading cells of epithelial origin.