There are several types of rare malignant ovarian tumors that together compose about 0.1% of ovarian malignancies. These lesions include small cell carcinomas, lipoid cell tumors and primary ovarian sarcomas.

This group of tumors includes granulosa cell tumors, thecomas, and fibromas. The granulosa cell tumor is a low-grade malignancy, and rarely thecomas and fibromas become malignant and are called fibrosarcomas.

Granulosa cell tumors, which…

Sex cord stromal tumors of the ovary account for about 5% to 8% of all ovarian malignancies. This group of ovarian neoplasms is derived from the sex cords and the ovarian stroma or mesenchyme.…

Mixed germ-cell malignancies of the ovary contain two or more elements of the lesions described above. In one series, the most common component of a mixed malignancy was dysgerminoma, which occurred in 80%, followed…

Pure nongestational choriocarcinoma of the ovary is an extremely rare tumor. Histologically, it has the same appearance as gestational choriocarcinoma metastatic to the ovaries. The majority of patients with this cancer are younger…

Embryonal carcinoma of the ovary is an extremely rare tumor. It can be distinguished from a choriocarcinoma by the absence of syncytiotrophoblastic and cytotrophoblastic cells. Embryonal carcinomas may be hormonally active, with some patients developing…

Endodermal sinus tumors (EST) have also been referred to as yolk sac carcinomas, because they are derived from the primitive yolk sac. These lesions are the third most frequent malignant germ cell tumor of…

Immature teratomas contain elements resembling tissues derived from the embryo. Immature teratomatous elements may occur in combination with other germ cell tumors as mixed germ cell tumors. The pure immature teratoma accounts for less than…

Dysgerminomas are the most common malignant germ cell tumors, accounting for about 30% to 40% of all ovarian cancers of germ cell origin. The tumor represents only 1% to 3% of all ovarian cancers, but as…

When an adnexal mass is 2 cm or larger in a premenarchal female, or 8 cm or larger in other premenopausal females, surgical exploration is frequently required. In young patients, blood tests should…

Germ cell tumors are derived from the primordial germ cells of the ovary. Whereas malignant germ cell tumors can arise in extragonadal sites, such as the mediastinum and the retroperitoneum, the majority of germ…

Introduction

Nonepithelial cancers of the ovary are uncommon. They include malignancies of germ cell origin, sex cord-stromal cell origin, metastatic carcinomas to the ovary, and a variety of extremely rare ovarian cancers, such as…