A Rare Cause of Intestinal Obstruction: Invasive Lobular Breast Carcinoma Metastasizing to the Ileocecal Valve.

Invasive lobular carcinoma (ILC) has a higher propensity for gastrointestinal metastases compared to invasive ductal carcinoma (IDC). We present the case of a 65-year-old woman with metastatic ILC who developed intestinal obstruction due to ileocecal metastases 30 months after undergoing total mastectomy and adjuvant therapy for left-sided breast cancer (BC). Abdominal computed tomography (CT) demonstrated a transition point at the ileocecal valve. Surgical resection was performed to relieve the small bowel obstruction, and histopathology confirmed metastatic ILC with receptor discordance compared to the primary tumor. This case highlights the diagnostic and therapeutic challenges of intestinal metastases from BC, including receptor conversion and resistance to therapy. Molecular profiling and tailored treatment are crucial for optimal management of complex metastatic disease.