Clinical pathology of metastatic gastric carcinoma to the breast: A report of two cases and a review of literature.

The breast is an unusual site for metastasis from a gastric carcinoma. The present study reports two cases of metastatic gastric carcinoma to the breast. The first patient, a 37-year-old woman, initially presented with gastric adenocarcinoma, prior to developing metastatic cancer to the breast 4 years later. The second female patient presented with a breast mass, and a modified radical mastectomy was performed; however, the subsequent pathological examination revealed the mass to be a metastatic signet ring cell carcinoma. An abdominal computed tomography scan revealed a diffuse gastric wall thickening that was consistent with gastric cancer. The findings suggest that immunohistochemistry is a useful tool to differentiate between primary breast tumors and gastrointestinal carcinomas that have metastasized to the breast. Additional studies are required in order to define the optimal treatment.