Gastric Outlet Obstruction as an Unusual Presentation for Metastatic Lobular Breast Cancer

[...]evaluation to rule out malignancy is therefore warranted in patients with negative endoscopic biopsies, but who are aged more than 50 years, have a positive family history of gastric cancer, and have no history of PUD.2 Furthermore, if endoscopic biopsies are positive for malignancy, a primary GI tumor is often presumed to be the underlying cause of obstruction despite the possibility, albeit rare, of metastatic disease to the duodenum arising primarily from outside the abdomen. [...]without the chest CT, the patient would have been treated for a primary GI tumor because of the pathology findings of the duodenal biopsy that demonstrated signet ring adenocarcinoma. [...]another unique feature of this case report is that the duodenal biopsy contained signet ring cells. ExtraGI causes of metastatic duodenal lesions include and are not limited to melanoma, lung cancer, renal cell carcinoma, and, in the rare case, breast cancer. Because of the rarity of breast cancer metastasis to the GI tract, the etiology was overlooked as a cause of GOO because of the assumption of primary gastric cancer.