Breast metastasis from rectal carcinoma: A case report and review of the literature

Dan-Dan Wang¹, Su-Jin Yang¹, Wei-Xian Chen^*2

1. Department of Breast Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
2. Department of Breast Surgery, The Affiliated Changzhou No. 2 People’s Hospital of Nanjing Medical University, Changzhou 213000, Jiangsu
   Province, China

Correspondence: Wei-Xian Chen (chenweixian@njmu.edu.cn)

Abstract
Background
Metastasis from extramammary primary tumor to breast is extremely rare.
Case Summary A 59-year-old woman with 1-year history of rectal cancer presented with asymptomatic breast mass. At 16 months after the diagnosis of rectal mucinous adenocarcinoma, a breast mass was confirmed by ultrasonography and identified by pathology and immunohistochemistry as a metastasis from the rectal cancer. Treatments included chemotherapy (6 cycles: 300 mg irinotecan on day 1, 4.5 mg raltitrexed on day 2, 450 mg bevacizumab on day 3), radiotherapy, and surgical resection. Two years of follow-up examinations (6-months intervals) showed no evidence of recurrence or novel distant metastasis.
Conclusion
Breast metastasis from rectal carcinoma is a rare secondary malignancy. Final diagnosis can be established by histopathology and immunohistochemistry.
Key words: Breast cancer; Rectal carcinoma; Metastasis; Case report; Secondary malignancy; Review