INTRODUCTION: Breast cancer usually metastasizes to bone, lung, liver, or brain, and it is extremely rare to metastasize to gastrointestinal tract. We report a unique case of breast cancer metastasizing to stomach. We have noted only a few similar cases in current literature. CASE DESCRIPTION/METHODS: A 71-Yr-Old Caucasian female was referred for evaluation of upper abdominal pain, nausea, and occasional vomiting for 3months. Denies excess NSAID use, melena, or hematochezia. She has history of Hodgkin's lymphoma in remission after chemoradiation 40 years ago, and bilateral metastatic breast cancer diagnosed five years ago. She initially was found to have bilateral breast masses on mammogram. Biopsies showed invasive mammary carcinoma with extensive lobular pattern in right breast and invasive ductal carcinoma in left breast. PET-CT scan showed innumerable mixed sclerotic and lytic lesions throughout axial and appendicular skeleton. She was started on endocrine therapy as she declined chemotherapy. Laboratory values include normal liver function tests, and complete blood counts. Upper endoscopy showed moderately severe erythematous mucosa, and multiple small nodules throughout the stomach. Biopsies showed infiltrative tumor cells in nests and cords, some with signet ring cell features and mucin production. Immunohistochemical staining showed positive GATA-3 and ER which confirmed poorly differentiated adenocarcinoma of primary breast origin. She had another endoscopy a year ago which showed similar biopsy findings at an outside facility. Currently, she has been receiving capecitabine and following with oncology. DISCUSSION: Metastasis to gastrointestinal tract from other solid organ cancers is very rare. Breast cancer, mainly invasive lobular carcinoma, metastasizing to gastrointestinal tract, noted in <1% cases. It usually involves rectum, stomach, small bowel, and esophagus. Metastases to stomach mimic primary gastric cancer on imaging and endoscopically. Symptoms are nonspecific including abdominal pain, nausea, early satiety, bloating, and weight loss. Endoscopically, the stomach may have diffuse infiltration as linitis plastica, isolated, or multiple nodules, or a superficial mucosal lesion. Histological features especially immunohistochemical markers like GCDFP-15 and GATA 3 expression help to differentiate from primary gastric adenocarcinoma. Our patient had non-specific upper gastrointestinal symptoms. Endoscopy and biopsies confirmed the diagnosis.