There has been debate over the exact mechanism of metastasis of the tumor cells from the stomach, appendix or colon to the ovaries. Classically it was thought that direct seeding across the abdominal cavity accounted for the spread of this tumor, but spread by way of the lymphatic is considered more likely. Retrograde lymphatics are thought to be more important in the pathogenesis of<unk> r, since the ovaries in<unk> r do not show capsular invasion or a breech of the epithelium lining the surface. The average age of diagnosis of<unk> s may partly relate to the relatively increased vascularity of the ovaries. Microscopically,<unk> s are often characterized by mucin-secreting signet-ring cells in the tissue of the ovary; when the primary tumor is discovered, the same signet-ring cells are typically found. However, other microscopic features can predominate.<unk> s are most commonly metastases from gastric cancer, particularly adenocarcinoma, or breast cancer particularly invasive lobular breast carcinoma, but they can arise in the appendix, colon, small intestine, rectum, gallbladder, and urinary bladder or gallbladder, biliary tract, pancreas, ampulla of Vater or uterine cervix. Immunohistochemistry may help in diagnosing<unk> s from primary ovarian neoplasms but needs to be applied with discretion. For example, tumors that are immunoreactive to CEA or cytokeratin 20 (CK20) and negative for cytokeratin 7 (CK7) may be more likely to be of colorectal origin.
Krukenberg tumor
Brenner tumour
Nesidioblastoma
Koenen's tumor
Ceruminous adenoma
Askin's tumor
Thecoma
Lipoblastoma