Gastric cancer is a disease of elderly patients and mainly metastasis to liver, lung, and peritoneum, while signet ring cell is a variant of gastric cancer and commonly metastasis to peritoneum and lymph nodes. Metastasis to mammary is a rare condition which account for 3% and has poor prognosis. Generally extra mammary carcinoma precedes breast metastasis by 2 years. It's uncommon to have breast metastasis as a first manifestation of extra mammary malignancies. There is no age limit and presentation my mimic primary breast cancer. Due to rarity of this condition there are no consensuses about clinical, radiological and histological features which make it a challenging task to distinguish primary from metastatic breast neoplasm. The case bellow is a young woman with diagnoses of diffuse-signet ring cell gastric cancer. First presentation was right breast edema with ascites, peritoneal nodules, and enlarged enhancing ovaries on imaging. Biopsy from each site confirmed involvement by metastatic adenocarcinoma with signet ring pattern. Her condition progressed after 5th cycle of EOX. Keywords: Gastric cancer, breast metastasis, young ageNidhamalddin et al. / Breast cancer metastasis from Gastric Carcinoma in a young female 2 / 7