Introduction

Breast cancer is the most common malignancy in women, with invasive lobular carcinoma (ILC) accounting for up to 20% of cases. Gastrointestinal metastases are rare, reported in 0.04–18% of cases, with the stomach being the most frequently affected site, followed by colon and rectum. Non-specific symptoms often lead to delayed diagnosis, particularly years after the primary tumor.

Case Report

A 62-year-old woman with a history of right breast ILC (T2N1M0), treated over 10 years ago with surgery, radiotherapy, chemotherapy, and hormone therapy for hormone receptor-positive disease, had previously developed bone and liver metastases managed with systemic therapy. She presented with epigastric pain radiating retrosternally and associated autonomic symptoms. Laboratory tests showed microcytic hypochromic anemia and elevated tumor markers (CA 15-3, CEA).

Gastroscopy revealed a 1-cm excavated ulcer on the greater curvature of the gastric body, posterior wall, with a fibrin-covered base and edematous, congestive borders. Biopsies demonstrated atypical cells positive for estrogen and progesterone receptors, confirming metastatic breast carcinoma.

Discussion

Gastric metastases from breast cancer, especially ILC, can occur months to decades after initial diagnosis (reported intervals 3 months–30 years). Clinical manifestations are often subtle, including abdominal discomfort, dyspepsia, or GI bleeding, and mimic primary gastric cancer. Endoscopic evaluation combined with histopathology and immunohistochemistry (ER/PR, GATA-3) is essential for diagnosis. Recent literature confirms the rarity of this entity (~0.04–0.3% in large cohorts) but highlights its relevance for guiding systemic therapy rather than surgical management. Awareness is crucial to differentiate metastatic lesions from primary gastric malignancies, avoid unnecessary surgery, and initiate appropriate systemic treatment.

Conclusion

This case underscores the importance of considering gastric metastases in patients with a history of invasive lobular breast carcinoma presenting with upper GI symptoms, even many years after the primary tumor. Endoscopic biopsy with immunohistochemical confirmation enables accurate diagnosis and informs optimal systemic management, preventing unnecessary surgical interventions and improving patient care.