The authors report the case of a 75-year-old female patient who presented with a deterioration in her general health and epigastralgia 30 years after mastectomy for cancer. The findings of an exhaustive assessment was normal apart from an inflammatory syndrome with hyperleukocytosis and subcardial ulceration, which gave negative endoscopic biopsies. The patient underwent surgery and the total gastrectomy ablation demonstrated that this was a metastasis of a mammary adenoma. Follow-up for two years did not reveal any recurrence. The mean time to the development of gastric metastases of breast cancers is 2 to 4 years. Life expectancy appears to be greater the longer this latency time. The usual blood-borne spread explains why endoscopic biopsies may be falsely reassuring, since the first layers to be affected are the serous and submucosal layers. Localized forms may simulate ulcers; nodular forms are more appropriate for curative surgery than the more common infiltrating forms (which resemble linitis). These infiltrating forms are often combined with peritoneal damage and/or extradigestive metastases.