Pathology of Epithelial Ovarian Tumors

Abstract

Various types of epithelial tumors occur in the ovary. They are classified according to the phenotype of the tumor cells, patterns of growth, and malignant potential. The major phenotypical categories are serous, mucinous, endometrioid, clear cell, Brenner, and seromucinous tumors. Tumors of each category are subclassified as benign, borderline malignancy/atypical proliferative tumor, or malignant (carcinoma). Phenotypically, tumor cells of serous tumors resemble the tubal epithelium. Tumor cells of mucinous tumors are similar to the gastrointestinal epithelium. Endometrioid and clear cell tumors have epithelium resembling endometrial glandular cells, with the latter recapitulating the morphology of the Arias-Stella reaction. Brenner tumors show characteristics of the urothelium. Seromucinous tumors show proliferation of various types of Mullerian epithelium. Recent studies have revealed the tumorigenesis of each type of ovarian epithelial tumor, thus establishing new concepts of ovarian carcinogenesis. These findings and concepts are reflected in the last (4th) edition of the World Health Organization classification of ovarian tumors. In this chapter, the clinicopathological features, etiology, gross and microscopic features, and certain molecular mechanisms of each type of ovarian epithelial tumor are discussed.