SHM Converge Scientific Abstract ePoster Gallery-A Rare Case of Gastrointestinal Metastases From Primary Breast Cancer

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This case describes a 56-year-old woman with a history of invasive lobular breast cancer diagnosed 8 years earlier who developed progressive abdominal pain, nausea, vomiting, poor appetite, and weight loss while receiving neratinib and capecitabine. Initial imaging showed gastric antral thickening with intra- and extrahepatic biliary ductal dilation. MRCP demonstrated biliary wall thickening, tapering at the ampulla, and peritoneal/omental changes. EGD revealed an intramural/subepithelial lesion in the gastric antrum and prepyloric region causing gastric outlet stenosis, leading to gastrojejunostomy and pyloric stent placement.<br /><br />Fine-needle aspiration of the gastric lesion showed malignant cells infiltrating the gastric wall. Immunohistochemistry was positive for GATA-3 and negative for CDX-2 and E-cadherin, supporting metastatic adenocarcinoma of breast origin with lobular phenotype.<br /><br />The patient later re-presented with epigastric pain and evidence of pancreatobiliary obstruction and inflammation, including lipase 3000 U/L, elevated liver enzymes, bilirubin, and alkaline phosphatase. CT showed worsening gallbladder distention, and EUS/ERCP identified duodenal stenosis along with strictures of the main bile duct and pancreatic duct. She subsequently developed diet intolerance, and CT suggested jejunal dilation with narrowing concerning for malignant partial small bowel obstruction. She required temporary total parenteral nutrition until oral intake improved, after which chemotherapy was resumed.<br /><br />The discussion emphasizes that gastrointestinal metastases from breast cancer are rare but occur more often with invasive lobular carcinoma than ductal carcinoma. These metastases can closely mimic primary gastrointestinal tumors clinically and radiographically, making diagnosis challenging. In patients with a history of breast cancer—especially lobular subtype—persistent nonspecific GI symptoms refractory to initial treatment should prompt evaluation for metastatic disease.

Asset Subtitle

Daniel Aldrich

Meta Tag

Author List Daniel Aldrich, Elizabeth J. Terman, Ethan Molitch-Hou

Category Clinical Vignettes

Concept Gastrointestinal Metastasis

Concept Breast Cancer

Concept Invasive Lobular Carcinoma

Concept Metastatic Breast Cancer

Concept Endoscopy

Distinguished Non-Finalist

Presenter Organization Section of Hospital Medicine, Department of Medicine, University of Chicago

Presenting Author Daniel Aldrich

Track Adult

Keywords

invasive lobular breast cancer

gastrointestinal metastasis

gastric outlet obstruction

biliary ductal dilation

gastric antral thickening

EUS ERCP

peritoneal metastasis

GATA-3 positive

CDX-2 negative

small bowel obstruction

Gastrointestinal Metastasis

Breast Cancer

Invasive Lobular Carcinoma

Metastatic Breast Cancer

Endoscopy