Krukenberg Tumor - Pathogenesis

Pathogenesis

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. The average age of diagnosis of Krukenberg tumors may partly relate to the relatively increased vascularity of the ovaries.

Microscopically, Krukenberg tumors 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. Krukenberg tumors 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 Krukenberg tumors 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.