Rare benign lesions of the breast

In this review a wide-range of uncommon benign breast lesions, which can present as a breast mass, are described and discussed. The entities are loosely grouped into five sections; developmental lesions, in which all components of the normal breast are present, epithelial lesions, stromal lesions, lesions associated with luminal secretion and, finally, a group of soft tissue lesions, which although not specific to the breast can present in the breast. We have attempted to address the common diagnostic pitfalls associated with the lesions described.