Trichoblastic Fibroma of the Skin Mimicking Primary or Secondary Breast Cancer

We report a case of a 71-year- old female with trichoblastic fibroma, a rare benign tumor of the skin, found in the left breast, associated with an invasive contralateral breast cancer. On clinical examination, a solitary, firm nodule was found in the subcutaneous tissue of the left breast with no changes in the overlying skin. Radiological examination showed disconcordant results. Conventional mammography and ultrasound suggested benign nature, while magnetic resonance mammography and spectroscopy raised the presumption of the malignant nature of the lesion. After performing excisional biopsy, the diagnosis of trichoblastic fibroma was established. Microscopically, it was composed of fibrous stroma, basaloid germs and strands and lace-like epithelial components, with no obvious connection with overlying epithelium or adjacent adnexal structures.