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.