Gastric tumor from metastasis of breast cancer.

Metastatic tumours of the stomach have been reported to result from various types of cancer. Among them, gastric metastasis from breast cancer has been recognised in 0.3-18% patients (1-4). Here, a rare case of metastatic gastric tumour derived from breast carcinoma is reported. Gastric endoscopy confirmed a large, friable mass (approximately 5 cm in diameter) in the upper part of the gastric body. The mass within the stomach was difficult to distinguish from primary gastric cancer, although biopsies of this lesion revealed the characteristics of adenocarcinoma. In addition, immunohistochemistry showed the positive expression of mammaglobin. Taken together, the evidence pointed to metastasis of breast cancer to the stomach. The patient was treated with hormonal therapy (letrozole), and the size of the metastasis in the stomach was markedly reduced. Therefore, a gastric metastasis from breast cancer was diagnosed successfully using immunohistochemistry and unnecessary surgery was avoided. In conclusion, although gastric metastatic tumours derived from breast carcinoma are rare, their accurate pre-operative diagnosis and appropriate systemic treatment is essential. Metastatic cancer to the stomach is uncommon. The most frequently reported primary tumours include lung and breast cancer, as well as malignant melanoma (1-4). Metastases are more common in the gastric body and fundus and usually occur singularly rather than as multiple metastases. Diagnosis can be difficult as the tumour-free interval is often prolonged and benign lesions commonly appear. Gastric metastasis from breast cancer has been recognised in 0.3- 18% patients (5-12). Therefore, the discovery of a gastric tumour in a patient with a history of breast cancer is more likely to be a primary gastric lesion, but a metastasis from the breast cancer is possible and must not be ruled out. Differential diagnosis between the two tumours is essential for ensuring correct