Metastatic breast cancer manifested as refractory anemia and gastric polyps

Gastric metastasis from breast cancer is uncommon and typically occurs in patients with disseminated disease. The vast majority of patients with gastric lesions have a known preexisting diagnosis of breast cancer. In contrast, we describe a case in which a minimal breast cancer was found to be the primary tumor during the workup of a patient first diagnosed with carcinoma of unknown primary and subsequently presumed to have metastatic gastric cancer. Our case illustrates that a diagnosis of breast cancer metastatic to the stomach may require a high index of suspicion, as well as a meticulous breast workup. It also emphasizes that even tiny breast cancers have a small but real risk of metastatic spread. Determination of the correct primary source in these cases may not be only an academic exercise, since the treatment and prognosis of metastatic breast cancer (especially receptor positive) and metastatic gastric cancer are different.