Unveiling the Unexpected: Duodenal Ulcer as a Manifestation of Breast Cancer Metastasis.

Breast cancer typically metastasizes to the lymph nodes, lungs, bones, and liver. However, gastrointestinal (GI) involvement is exceedingly rare, particularly presenting as duodenal ulcers. Such metastases often mimic primary GI malignancies, leading to nonspecific symptoms like abdominal pain, anorexia, bleeding, and vomiting, which can delay accurate diagnosis. Early recognition through appropriate diagnostic evaluations is crucial to prevent disease progression. We report a unique case of an 86-year-old woman with multiple comorbidities who presented with multiple gastrointestinal ulcers. Further investigation revealed these lesions to be manifestations of metastatic breast cancer. This case underscores the importance of considering metastatic breast cancer in the differential diagnosis of atypical gastrointestinal presentations, even in elderly patients without a known history of malignancy.