Breast Cancer Metastasis to the Gastrointestinal Tract With Unusual Endoscopic and Histologic Presentations

Abstract

ABSTRACT The gastrointestinal (GI) tract is an infrequent site of breast cancer metastasis, but it often poses a diagnostic challenge when it occurs. The symptoms of GI metastases are often nonspecific, and the endoscopic manifestations are variable, requiring tissue biopsies for histologic examination. We report 2 cases of breast cancer metastasizing to the GI tract: a case of human epidermal growth factor receptor 2-positive invasive ductal carcinoma that metastasized to the stomach, a rare location for this histologic subtype, and another case of invasive lobular cell carcinoma that metastasized to the colon with unusual findings of mucosal pallor and edema on colonoscopy.