SECONDARY OVARIAN CARCINOMA
Metastatic cancer of the ovary accounts for only about 5% of ovarian cancer. The ovary is particularly prone to metastatic invasion by carcinoma. The primary sites include the breast, stomach, small and large intestine, appendix, liver, gallbladder, bile ducts, pancreas, uterus, tubes, opposite ovary, bladder and ureters, lungs, and meninges. Frequently, metastases are from primary tumors that originate elsewhere in the female reproductive tract, particularly from the endometrium and fallopian tube. Secondary ovarian carcinoma is most frequently seen from the fourth to the sixth decades of life. The ovaries are bilaterally involved in 66% to 75% of cases. Ascites is often evident (50%). The ovarian neoplasms may be asymptomatic or may manifest symptoms and signs similar to those produced by primary ovarian carcinoma. In the presence of a known primary lesion and palpable enlargement of the ovaries, the diagnosis of secondary carcinoma may reasonably be suspected. Similarly, the discovery of bilateral, solid ovarian growths on pelvic examination is an indication for a thorough search for a primary source elsewhere. Esophagoscopy, gastroscopy, sigmoidoscopy, or colonoscopy should be considered as a part of the evaluation when a gastrointestinal source is being sought.
In fully half of the cases, the ovarian lesion may not be detectable grossly. The tumors may be minute or enlarged to diameters of 20 to 30 cm. The general contour of the ovary is usually retained. The typical secondary ovarian carcinoma is of moderate size, oval or kidney shaped, smooth or lobulated, ﬁrm, grayish white in color, with a well-developed capsule and little tendency toward adhesions. Depending upon the presence of necrosis, cystic degeneration, hemorrhage, myxomatous changes, and the degree of connective tissue proliferation, the cut surface may be ﬁrm, spongy, partly cystic, or gelatinous and grayish white or yellow in color, with hemorrhagic areas of red or brown.
The histologic picture is generally similar to that of the primary lesion. The anaplastic, epithelial elements may appear as clusters of acini, cords, masses, or sheets, with varying degrees of mucoid change. The stroma may be abundant or sparse, cellular, edematous, and myxomatous.
The Krukenberg tumor refers to a secondary ovarian carcinoma that manifests marked proliferation of the connective tissue elements, sarcoma-like areas, epithelial anaplasia, and mucoid epithelial and myxomatous changes. Krukenberg tumors are the third most common metastatic ovarian cancer (after epithelial and germ-cell tumors) and make up 14% of these cancers. Unlike some forms of cancer, there is no racial bias. Signet-ring cells, in which the nucleus is ﬂattened to one side by secretion distending the cell, are characteristic. The most common site of origin is the stomach or large intestine, though metastatic breast cancer may appear similar histologically. Metastatic tumors from the gastrointestinal tract to the ovary can be associated with sex hormone production, usually estrogen. A few cases of Krukenberg tumors have been described with no apparent distant primary malignancy, suggesting the rare possibility of a primary ovarian tumor with the histologic features of a Krukenberg tumor.
Debate exists over the exact mechanism of metastasis of the tumor cells from the gastrointestinal tract to the ovaries; classically, it was thought that direct seeding across the abdominal cavity accounted for the spread of this tumor, but some have suggested that lymphatic or hematogenous spread is more likely, as most of these tumors are found in the ovarian parenchyma and not the surface.
The prognosis in secondary ovarian carcinoma is extremely grave, with 5-year survival unlikely. Progression and spread of the primary tumor are generally well under way when the ovarian sites are discovered. If widespread metastases are evident, surgery is not indicated. If the diagnosis is conﬁrmed on laparotomy, a total hysterectomy and bilateral salpingo-oophorectomy may make the patient temporarily more comfortable.