The most common sites of
breast cancer metastasis are the bone, liver, lung and brain, while gastrointestinal
metastasis from
breast cancer is rare. We herein present the case of a 68-year-old woman who was admitted to our department with
nausea and appetite loss. The patient's medical history included right
mastectomy with sentinel lymph node biopsy 5 years earlier for invasive
lobular carcinoma, measuring 6.2 cm in greatest diameter, without lymphovascular invasion. Two years after the surgery, the patient developed brain
metastasis and underwent
metastasectomy to control the neurological symptoms, including unsteadiness and
asthenia. After the second surgery, the patient received systemic
chemotherapy using S-1, followed by
bevacizumab plus
paclitaxel. However, due to
bevacizumab-related
cardiotoxicity, the treatment was switched to
eribulin. On esophagogastroduodenoscopy, an elevated lesion was identified in the antrum, causing severe narrowing of the gastric outlet. Biopsy and histological examination of the
tumor revealed infiltration of the gastric wall by undifferentiated neoplastic cells with poor adhesion, morphologically similar to invasive
lobular carcinoma, and immunohistochemical staining was positive for
estrogen receptor, mammaglobin and GATA3. Finally, 18F-2-deoxy-2-fluoro-D-glucose (FDG) positron emission tomography combined with computed tomography imaging revealed FDG uptake across the thickness of the
antral wall. The patient was diagnosed with gastric
metastasis from the original
breast cancer and subsequently underwent endoscopic
self-expandable metallic stent (SEMS) placement. There were no procedure-related adverse events, and the patient remained alive under best supportive care 4 months after SEMS placement. To the best of our knowledge, this is the first reported case of
gastric outlet obstruction caused by metastatic
breast carcinoma managed by SEMS placement. While such a diagnosis is rare, clinicians treating patients with gastric
metastases should be aware of possible
gastric outlet obstruction and SEMS placement as an effective palliative intervention.