Analysis of proliferative activity of pleomorphic adenoma of salivary gland with DNA-photocytometry

Abstract

Proliferative activity of pleomorphic adenomas of salivary glands was examined by measuring the nuclear DNA content on tissue sections by means of photocytometry. Pleomorphic adenoma is histologically characterized by its pleomorphic or mixed appearance and its clearly recognizable epithelial tissue intermingled with areas of myxoid or chondroid appearance. The ductal tissues of the tumor are composed of two main epithelial cell types, inner duct-lining cells and outer myoepithelial-like cells. These tumor cells of various areas were evaluated. Cells in sites of abundant cellular components showed higher activity. The activity of cells in sites with abundant cellular components in Ga scintigraphy-positive patients was greater than that in Ga-negative patients. There was no difference in activity between inner duct-lining cells and outer myoepithelial-like cells. The activity of cells near the capsule was not necessarily higher. Pleomorphic adenomas of submandibular glands showed higher activity than those of parotid glands. Recurrent tumors did not show higher activity. Nuclear size and shape, as well as section thickness, need to be considered as principal variables influencing the result. This method is considered particularly effective for tumor of the salivary gland that is composed of various kinds of tumor tissues.