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.

Small-Cell Carcinomas

This rare tumor occurs at an average of 24 years (range 2 to 46 years). The tumors are all bilateral. Approximately two-thirds of the tumors are accompanied by paraendocrine hypercalcemia. This tumor accounts for one-half of all of the cases of hypercalcemia associated with ovarian tumors. About 50% of the tumors have spread beyond the ovaries when they are diagnosed.

 

The management of these maliganacies consists surgery followed by platinum-based chemotherapy and or radiation therapy. In addition to the primary treatment of the disease, control of the hypercalcemia may require aggressive hydration, loop diuretics and the use of phosphates. The prognosis tends to be poor with most patients dying within two years of diagnosis in spite of treatment.

Lipoid Cell Tumor
The lipoid cell tumor is thought to arise in adrenal cortical rests that reside near the ovary. Over 100 cases have been reported, and bilaterality in only a few. Most are associated with virilization, and occasionally with obesity, hypertension, and glucose intolerance, reflecting glucocorticoid secretion. Rare cases of hyperestrogenism and isosexual precocity occur.

The majority of lipoid cell tumors have a benign or low-grade behavior, but about 20%, most of which are initially larger than 8 cm in diameter, develop metastatic lesions. Metastases are usually within the peritoneal cavity, and rarely to distant sites. The primary treatment is the surgical extirpation of the primary lesion, and there are no reports of effective radiation or chemotherapy.

Sarcomas Malignant mixed mesodermal sarcomas of the ovary are rare, and only about 100 cases have been reported. Most are heterologous, and 80% occur in postmenopausal women. The presentation is similar to that of most ovarian malignancies, although these tumors are biologically aggressive, and the majority of patients have metastases to organ parenchyma, such as the liver and lung, and to the retroperitoneal lymph nodes.

Adriamycin, with or without cyclophosphamide, has produced an occasional partial response, and cisplatin is currently undergoing clinical trials. Ifosfamide with mesna has been reported to be useful in metastatic sarcomas of the female genital tract, and this combination might be appropriate for the treatment of ovarian sarcomas. Long-term survivors are uncommon, although some stage I patients have survived for 5 years.

Metastatic Tumors
About 5 to 6% of ovarian tumors are metastatic from other organs, most frequently from the female genital tract, the breast, or the gastrointestinal tract. The metastasis may occur from direct extension of another pelvic neoplasm, by hematogenous spread, by lymphatic spread, or by transcoelomic spread, that is, by surface implantation of the peritoneal cavity.

Gynecologic
Nonovarian cancers of the genital tract can spread by direct extension or metastasize to the ovaries. Tubal carcinomas involve the ovaries secondarily in 13% of cases usually by direct extension. Under some circumstances, it is difficult to ascertain whether the tumor originates in the tube or in the ovary when both are involved. Cervical cancer spreads to the ovary only in rare cases (less than 1%), and most of these are of advanced clinical stage or of adenocarcinoma histotype. Although adenocarcinoma of the endometrium can spread and implant directly onto the surface of the ovaries in as many as 5% of cases, two synchronous primaries probably occur with greater frequency. In these cases, there is usually an endometrioid carcinoma of the ovary associated with the adenocarcinoma of the endometrium. Malignant melanoma rarely can metastasize to the ovaries.

Non-Gynecologic
The reported frequency of metastatic breast carcinoma to the ovaries varies, but the phenomenon is common. In autopsy data of women who die of metastatic breast cancer, the ovaries are involved in 24% of cases and 80% of the involvement is bilateral. Similarly, when ovaries are removed to palliate advanced breast cancer, about 20% to 30% of cases reveal ovarian involvement, 60% bilaterally. The involvement of ovaries in early-stage breast cancer appears to be considerably lower, but precise figures are not available. In almost all cases, ovarian involvement either is occult or a pelvic mass is discovered after other metastatic disease becomes apparent.

Krukenberg
The Krukenberg tumor accounts for 30% to 40% of metastatic cancers to the ovaries and for 1% to 2% of all malignant ovarian tumors reported at some institutions. It involves the ovarian stroma and has characteristic mucin-filled, signet ring cells. The primary tumor is most often from the stomach, but less commonly from the colon, breast, or biliary tract, and rarely, from the cervix or bladder. Most are bilateral. The lesions may not be discovered until the primary disease is advanced, and most patients die of their disease within a year. In some cases, a primary tumor is not found.

In other cases of metastasis from the gastrointestinal tract to the ovary, the tumor does not have the classic histologic appearance of Krukenberg tumor, and most of these are from the colon and, less commonly, the small intestine. As many as 1% to 2% of women with intestinal carcinomas will develop metastases to the ovaries during the course of their disease. Prior to exploration for an adnexal tumor in a woman older than 40 years, a barium enema is indicated to exclude a primary gastrointestinal carcinoma with metastases to the ovaries. Metastatic colon cancer can mimic a mucinous cystadenocarcinoma of the ovary.

Carcinoid
Metastatic carcinoid tumors are rare, representing less than 2% of metastatic lesions to the ovaries. Conversely, only about 2% of primary carcinoids have evidence of ovarian metastasis, and only 40% of these patients have the carcinoid syndrome at the time of discovery of the metastatic carcinoid. Therefore, in perimenopausal and postmenopausal women with an intestinal carcinoid, it is reasonable to remove the ovaries to prevent subsequent metastasis. The discovery of an ovarian carcinoid should prompt a careful search for a primary intestinal lesion.

Lymphoma and Leukemia
Lymphoma and leukemia can involve the ovary, and when they do, the involvement is usually bilateral. Less than 5% of patients with Hodgkin’s disease develop lymphomatous involvement of the ovaries, and then typically only with advanced-stage disease. With Burkitt lymphoma, ovarian involvement is very common. Other types of non-Hodgkin lymphoma involve the ovaries more frequently than Hodgkin’s disease but leukemic infiltration of the ovaries is uncommon. Sometimes the ovaries can be the only apparent site of involvement of the abdominal or pelvic viscera with non-Hodgkin’s lymphoma, and if this circumstance is found, a careful surgical staging is necessary. If a frozen section of a solid ovarian mass reveals a lymphoma, the patient needs a careful operative evaluation, including a palpation of the entire intra-abdominal contents. Treatment for the lymphoma or leukemia involves the use of chemotherapy and/or radiotherapy appropriate for the specific type of primary lesion. Consideration should be given to removal of significantly enlarged ovarian disease to palliate symptoms and possibly to facilitate a response to treatment.