Lung cancer metastatic to breast: case report and review of the literature.

The incidence of metastases to the breast from nonbreast carcinoma is less than 1% of all breast cancers; of these, adenocarcinoma of the lung to breast is a small proportion (<0.1% of breast carcinomas). The imaging findings of a case of metastatic lung adenocarcinoma to the breast are presented with a review of the literature. Imaging findings including elastography suggesting the breast mass is not a primary breast cancer are highlighted. The importance of notifying the pathologist that nonbreast metastatic disease is in the differential is discussed. The use of appropriate tumor markers is needed; otherwise, the lesion may be interpreted as a triple negative breast cancer.