Case of Invasive Metastatic Breast Cancer Mimicking Crohn’s Disease

Abstract

Background: A female patient with a history of stage IIB invasive lobular breast cancer presented with symptoms of partial small bowel obstruction and workup led to a presumptive diagnosis of Crohn’s disease. However, at the time of surgical intervention, she was found to have metastatic lobular breast cancer with carcinomatosis and metastases to the small and large intestines. Summary: Our patient presented at age 55 with intermittent nausea and vomiting, dyspepsia, altered bowel habits, and weight loss. She had a history of invasive lobular carcinoma of the right breast treated with right modified radical mastectomy followed by adjuvant chemoradiation and hormonal therapy 5 years earlier. She was thought to be in remission. Initial workup of her GI complaints was notable for thickening of the sigmoid colon and hepatic flexure on CT scan and stricturing and colitis in these areas on colonoscopy. Mucosal biopsies showed nonspecific active colitis. The patient was treated for a presumptive diagnosis of Crohn’s disease without significant improvement. She was eventually taken for surgery after presenting with a high-grade small bowel obstruction. On exploration, numerous additional small and large bowel strictures, some associated with intraluminal masses, were found and a small bowel resection and ileostomy performed. Pathology revealed metastatic invasive lobular breast carcinoma. Although isolated metastases to the bowel wall are rare, they have been reported secondary to a wide range of malignancies. Breast cancer, especially lobular carcinoma, is one of the most common tumors to metastasize to the GI tract and can present years after the primary cancer diagnosis. Therefore, the differential diagnosis for a patient with signs and symptoms of bowel obstruction and a history of lobular breast cancer should include metastatic disease. Conclusion: Metastatic cancer to the GI tract can mimic Crohn’s disease and should be on the differential in older patients with abdominal complaints, particularly those with a history of breast cancer.