A barium enema or colonoscopy is indicated in selected patients with symptoms and signs suspicious for colon cancer. This study should be performed for any patient who has evidence of occult blood in the stool or of intestinal obstruction. An upper gastrointestinal radiographic series or gastroscopy is indicated if there are upper gastrointestinal symptoms such as nausea, vomiting, or hematemesis (3,108). Bilateral mammography is indicated if there is any breast mass, because breast cancer metastatic to the ovaries can simulate primary ovarian cancer.
A Papanicolaou (Pap) test should be performed, although its value for the detection of ovarian cancer is very limited. Patients who have irregular menses or postmenopausal vaginal bleeding should have endometrial biopsy and endocervical curettage to exclude the presence of uterine or endocervical cancer metastatic to the ovary.
Differential Diagnosis Ovarian epithelial cancers must be differentiated from benign neoplasms and functional cysts of the ovaries (100–102). A variety of benign conditions of the reproductive tract, such as pelvic inﬂammatory disease, endometriosis, and pedunculated uterine leiomyomata, can simulate ovarian cancer. Nongynecologic causes of a pelvic tumor, such as an inﬂammatory or neoplastic colonic mass, must be excluded. A pelvic kidney can simulate ovarian cancer.
Patterns of Spread Ovarian epithelial cancers spread primarily by exfoliation of cells into the peritoneal cavity, by lymphatic dissemination, and by hematogenous spread.
Transcoelomic The most common and earliest mode of dissemination of ovarian epithelial cancer is by exfoliation of cells that implant along the surfaces of the peritoneal cavity.
The cells tend to follow the circulatory path of the peritoneal ﬂuid. The ﬂuid moves with the forces of respiration from the pelvis, up the paracolic gutters, especially on the right, along the intestinal mesenteries, to the right hemidiaphragm. Metastases are typically seen on the posterior cul-de-sac, paracolic gutters, right hemidiaphragm, liver capsule, the peritoneal surfaces of the intestines and their mesenteries, and the omentum. The disease seldom invades the intestinal lumen but progressively agglutinates loops of bowel, leading to a functional intestinal obstruction. This condition is known as carcinomatous ileus (3).
Lymphatic Lymphatic dissemination to the pelvic and para-aortic lymph nodes is common, particularly in advanced-stage disease (109–111). Spread through the lymphatic channels of the diaphragm and through the retroperitoneal lymph nodes can lead to dissemination above the diaphragm, especially to the supraclavicular lymph nodes (109). Burghardt et al. reported that 78% of patients with stage III disease have metastases to the pelvic lymph nodes (111). In another series, the rate of para-aortic lymph nodes positive for metastasis was 18% in stage I, 20% in stage II, 42% in stage III, and 67% in stage IV (109).
Hematogenous Hematogenous dissemination at the time of diagnosis is uncommon.
Spread to vital organ parenchyma, such as the lungs and liver, occurs in only about 2% to 3% of patients. Most patients with disease above the diaphragm when diagnosed have a right pleural effusion (3). Systemic metastases appear more frequently in patients who survived for some years. Dauplat et al. reported that distant metastasis consistent with stage IV disease ultimately occurred in 38% of the patients whose disease was originally intraperitoneal (112).