Pilomatrixoma of the breast, a rare lesion simulating breast cancer: a case report.

Pilomatrixoma or calcifying epithelioma of Malherbe is a rare, benign, skin tumour originating from piliferous follicles; breast localization is considered to be very rare. These lesions can origin from the peri-areolar piliferous bulbs and, due to the clinical and imaging features, be easily misdiagnosed as a breast neoplasm. We present a case of pilomatrixoma of the left breast in a woman of 43 years appearing as a firm, deep nodule in the external quadrants. The lesion had mammographic and sonographic malignant features, but histological analysis on core-needle biopsy and surgical specimens revealed this unusual benign lesion.