Imaging Characteristics of Extramammary Metastases to the Breast

Extramammary metastases to the breast are rare and may present as either the first clinical sign of systemic malignancy or as part of advanced disseminated malignancy.Accurate diagnosis is essential because both management and prognosis differ from those associated with primary breast carcinomas.These metastases spread through the hematogenous or lymphatic pathways, resulting in diverse imaging findings.They may present as solitary or multiple masses or as diffusely infiltrative lesions and often mimic benign lesions, primary breast cancer, or inflammatory breast cancer.Although uncommon, extramammary breast metastases should be included in the differential diagnosis when radiologists encounter suggestive imaging findings in the patient's clinical history and prior imaging.This pictorial essay categorizes the imaging features of breast metastases by lesion type and presents representative cases, with the aim of improving the recognition of these rare lesions and facilitating accurate diagnosis.