OBJECTIVETo discuss the clinicopathological features and prognosis of metastases to the breast from extramammary solid tumors.

METHODSThe databases of Cancer Hospital of Chinese Academy of Medical Sciences from January 2001 to December 2012 were reviewed. 24 patients were identified with a diagnosis of metastasis to the breast from extramammary solid tumors and their clinical data were collected and analyzed. All the primary solid tumors and breast lesions were confirmed by pathology or cytology.

RESULTSOf the 24 patients, 22 were women and two were men. The median age was 54 years. The primary malignancies included non-small cell lung cancer (n = 10), small cell lung cancer (n = 4), rhabdomyosarcoma (n = 3), olfactory neuroblastoma (n = 3), ovarian cancer (n = 2), malignant melanoma (n = 1) and gastric cancer (n = 1). 15 patients (62.5%) complainted self-palpable breast nodules, two patients manifested as diffuse swollen and red of the whole breast, 7 patients (29.2%) were identified as well-defined nodules in the breast on CT images. The majority of metastases to breast presented as a solitary nodule with rapid growth, sometimes associated with axillary lymph node enlargement and occasionally with micro-calcification. Cytopathological examination could be used to differentiate the metastatic lesions from primary breast tumors. 83.3% (20/24) of the patients were concurrently accompanied with metastases in other organs and/or lymph nodes. The metastases to the breast from extramammy solid tumors were associated with a poor prognosis and the median overall survival was only 9.2 months.

CONCLUSIONSMetastasis to the breast should be considered in any patient with a known primary malignant tumor history who presents with a breast lump. Pathological examination should be performed to differentiate the primary breast cancer from metastatic tumor. An accurate diagnosis of breast metastases may not only avoid unnecessary breast resection, more importantly it is crucial to determine an appropriate and systemic treatment.