Metastasis to Breast from Extramammary Solid Tumors and Lymphomas: A 20-Year Population-Based Study.

To discuss the clinicopathological features and prognosis of metastases to the breast from extramammary solid tumors and lymphomas, we reviewed Cancer Hospital of Chinese Academy of Medical Sciences database from 01/01/2000 to 12/31/2020. Fifty-nine patients were identified. The most common primary sites for breast metastases were lymph node and pulmonary, followed by nasal cavity, ovary, skin, etc. All the patients were treated with chemotherapy, 18 were operated, 14 accepted radiotherapy. Metastasis to breast should be considered in any patient with tumor history presenting a breast lump. Pathological with immunohistochemical examination should be performed to identify the original site.