Virginia Tech Carilion School of Medicine Roanoke, VA
Shawna E. Bilton, BS1, Youssef Soliman, MD2, Badar Muneer, MD2, Douglas J. Grider, MD1, David P. LeBel, II, MD1; 1Virginia Tech Carilion School of Medicine, Roanoke, VA; 2Carilion Clinic, Roanoke, VA
Introduction: Metastatic disease occurs in 30% of breast cancer patients, with the most common sites of metastasis being lymph node, lung, liver, bone, or brain. Uncommonly, breast carcinoma metastasizes to the gastrointestinal tract. This report describes a rare case of a 48-year-old female with metastatic infiltrating ductal carcinoma to the colon
Methods: A 48-year-old female presented with chronic diarrhea and abdominal pain, and no reported history of melena or hematochezia. Laboratory results were negative for celiac and C. difficile, and abdominal CT was concerning for colitis. Colonoscopy was performed and the transverse colon was noted to be strictured and inflamed. Colonic biopsies demonstrated malignant poorly differentiated cells expanding the lamina propria, with an intact and non-dysplastic colonic epithelial surface. Immunohistochemistry demonstrated positivity for CK7, rare mammaglobin, BRST-2, and GATA3, compatible with breast origin. An E-cadherin immunohistochemical stain showed retained strong membranous staining, indicative of a ductal phenotype. A diagnosis of metastatic poorly differentiated adenocarcinoma compatible with breast origin was made. Review of the clinical history revealed the patient to have had an infiltrating ductal carcinoma of the breast eight years prior and is now status post left mastectomy with adjuvant Tamoxifen. Discussion: Breast metastasis to the gastrointestinal tract is uncommon, occurring in approximately 4-18% of metastatic breast cancer patients. Further, metastatic breast carcinoma to the colon is rare, estimated to occur in 3% of cases. Previously reported cases of gastrointestinal tract metastasis have predominantly been infiltrating lobular carcinoma. Infiltrating ductal carcinoma is known to metastasize to the lung, liver and bone, and there are few documented cases of metastasis to the colon. This reported case represents a rare finding of an infiltrating ductal breast carcinoma to the colon eight years after the initial diagnosis, diagnosed after colonoscopy and histopathological investigation. Breast metastasis to the gastrointestinal tract may present with vague signs and symptoms such as abdominal pain and changes in stool. Although rare, colonic metastasis should be considered in patients with a history of breast cancer who present with abdominal symptoms as early diagnosis will have a survival benefit.
Colonoscopy images of the transverse colon, demonstrating narrow lumen and inflammation.
(A-B) H&E. (C) BRST-2. (D) CK7 positive. (E) Mammaglobin, focally positive. (F) E-cadherin. (G) GATA-3 positive in the nuclei of many carcinoma cells. (H) CK20. (I) CDX2.
Disclosures: Shawna Bilton indicated no relevant financial relationships. Youssef Soliman indicated no relevant financial relationships. Badar Muneer indicated no relevant financial relationships. Douglas Grider indicated no relevant financial relationships. David LeBel indicated no relevant financial relationships.