The most common cystic neoplasms of the ovary.
In 60% of cases, serous tumors are benign, in 25% of cases are malignant and in 15% of cases are borderline.
20% of the benign tumors 30% of borderline tumors and 60% of malignant tumors are bilateral.
Grossly appear as a cystic mass up to 40 cm in diameter. The benign tumors have a smooth inner lining. In malignant tumors, papillary projections, solid areas and nodules may be seen within the inner surface of the tumor.
In the benign tumors, the lining consists of a single layer of tall columnar cells with eosinophilic cytoplasm. The cells may be ciliated and may form small papillary projections.
The borderline tumors cosist of one to several layers of cells, may exhibit atypia but lack any evidence of frank invasion.
The malignant tumors consist of one to several layers of cells, exhibit atypia and invade the stroma, capsule and the surrounding tissues.