Metastatic breast cancer diagnosed on upper gastrointestinal endoscopy

A woman in her late 60s was referred with a positive faecal immunochemical test and change in bowel habit; a suspicion of gastrointestinal (GI) cancer led to straight-to-test vetting for colonoscopy, which was unsuccessful due to a nontraversable, fixed sigmoid colon, secondary to prior hysterectomy and adhesions.Radiological evaluation with CT scanning revealed an abnormally thickened stomach, with subsequent upper GI endoscopy and biopsy findings confirming the presence of invasive poorly differentiated carcinoma consistent with metastatic invasive lobular carcinoma originating from the breast. Immunohistochemistry testing for gross cystic disease fluid protein was positive, and the tumour demonstrated positive oestrogen receptor status, while human epidermal growth factor receptor 2 status was negative. The immunohistochemical profile of this carcinoma was identical to that observed in synchronous breast cores, indicating metastatic invasive lobular carcinoma of the breast.This unusual presentation of breast cancer metastasis is not well recognised.