Case Report Identifies Breast Cancer Metastasis Mimicking Primary Colorectal Carcinoma

Breast cancer metastasis to the colon is a rare clinical occurrence, developing in less than 1% of patients diagnosed with metastatic breast cancer. While invasive lobular carcinoma demonstrates a distinct tropism for the gastrointestinal tract and adnexa, it frequently presents with atypical imaging characteristics that closely mimic primary colorectal malignancies.

In a newly reported clinical case documented in EJNMMI Reports, researchers described a 58-year-old woman with a medical history of right breast invasive lobular carcinoma who presented five years after undergoing a mastectomy.

Subsequent diagnostic workup utilized 2-[¹⁸F]FDG PET/CT imaging, which revealed multifocal hypermetabolic lesions situated in the transverse colon wall and bilateral adnexa. Further examination using CT enterography alongside colonoscopy confirmed the presence of a stenotic colonic lesion displaying smooth overlying mucosa.

Following surgical treatment comprising a right hemicolectomy, hysterectomy, and bilateral salpingo-oophorectomy, postoperative histopathology confirmed metastatic breast carcinoma involving the right colon and bilateral adnexa. The authors emphasized that this case demonstrates the critical role of PET/CT in identifying occult gastrointestinal metastases in invasive lobular carcinoma and highlights the necessity of evaluating metastatic disease when investigating colonic lesions in this patient cohort.

Subject of Research: Colonic metastasis from invasive lobular breast carcinoma

Article Title: Breast cancer metastasis to the colon mimicking primary colorectal carcinoma

Article References: Liu, Q., Gao, J., Yang, H., Chen, X., & He, Y. (2026). Breast cancer metastasis to the colon mimicking primary colorectal carcinoma. EJNMMI Reports, 10(1), Article 23. https://doi.org/10.1186/s41824-026-00306-7

Image Credits: AI Generated

DOI: 10.1186/s41824-026-00306-7

Keywords: breast cancer, invasive lobular carcinoma, colonic metastasis, differential diagnosis, PET-CT, CT enterography, colonoscopy, oncology, Breast, cancer, metastasis, colon