Gastric metastases from invasive lobular carcinoma of the breast: case report and literature review

BACKGROUND: Gastric metastases from breast cancer are rare clinical entities that often mimic primary gastric malignancies, leading to diagnostic delay. Invasive lobular carcinoma (ILC), due to its diffuse growth pattern and loss of E-cadherin expression, demonstrates a higher propensity for metastasizes to the gastrointestinal tract. METHODS: Clinical data for this study were retrospectively collected from the hospital's electronic clinical program. RESULTS: The authors report the case of a 42-year-old woman with bilateral stage IV ILC who subsequently developed bilateral ovarian and gastric metastases. We discuss the clinical, histopathologic, and imaging features, with emphasis on differential diagnosis and therapeutic strategies considering current evidence. CONCLUSION: This case highlights the diagnostic challenge of gastric metastases from ILC, which may present many years after the initial diagnosis. Definitive diagnosis requires immunohistochemistry to distinguish metastatic breast carcinoma from primary gastric carcinoma. Systemic therapy remains the mainstay of treatment, while surgical intervention should be reserved for selected palliative indications. Increased awareness of this rare manifestation is crucial to avoid misdiagnosis and optimize multidisciplinary management.