Pathological characteristics of common ovarian tumors

The case characteristics of common ovarian tumors are sometimes formed according to the classification on the cell group, including epithelial tumors, germ cell tumors, specific sex cord-stromal cell tumors, granulosa cell tumors, theca cell tumors, fibromas, and ovarian metastatic carcinomas.

Epithelial tumors

Epithelial tumors are the most common ovarian tumors, accounting for 50% to 70%. The age of onset is mostly between 30 and 60 years old, and it is rare before puberty. More than 80% of ovarian tumors in postmenopausal women are epithelial. Epithelial tumors are divided into benign, borderline and malignant.

1. Serous cystadenoma is common, accounting for 25% of benign ovarian tumors. The tumor is mostly unilateral, with bilateral accounting for 15%. The tumor surface is smooth, of varying sizes, and the cyst is filled with light yellow clear serous fluid. It is divided into two types: simple and papillary. The former is mostly single-chambered with smooth cyst walls, while the latter is mostly multi-chambered with visible nipples.

2. Serous cystadenocarcinoma is the most common of all malignant ovarian tumors, accounting for about 40% to 50%. One-third to one-half are bilateral. The tumor is often cystic and solid, large in size, smooth in surface, grayish white or with papillary growth, and multi-chambered in section, with papillary growth in the cavity, and turbid cystic fluid, sometimes bloody.

3. Mucinous cystadenoma is more common, accounting for about 20% of benign ovarian tumors. 95% are unilateral, large or huge, with a smooth surface. The cut surface is often multi-chambered, with cystic cavities of varying sizes, containing mucinous fluid, and papillary growth on the cystic wall. Microscopically, the cystic cavity is covered with a single layer of columnar epithelium that can secrete mucus, similar to the epithelium of the uterine endocervical canal. The rate of malignant transformation is 5% to 10%. About 2% to 5% are due to tumor rupture, and tumor cells are widely implanted on the peritoneal surface, secreting a large amount of mucus, forming peritoneal myxoma.

4. Mucinous cystadenocarcinoma accounts for about 10% of ovarian malignant tumors. It is mostly unilateral, with a large tumor body, solid cystic structure, and no papillae on the surface. The cross section is multi-chambered, with solid areas or papillae, extremely brittle tissue, and turbid or bloody cystic fluid.

5. Borderline tumors account for 15% of ovarian epithelial malignant tumors, mainly serous and mucinous borderline tumors. Other types of borderline tumors are rare. They are a type of low-grade potentially malignant tumor that is difficult to distinguish from benign or malignant tumors in appearance.