The management of solitary trichoepithelioma versus basal cell carcinoma.

Currently, all lesions diagnosed clinically as basal cell carcinoma (BCC) are treated by the excision of the lesion with 3-4 mm margins followed by histopathological examination to assess clearance and confirm the diagnosis. We present the findings of surgical incisional and excisional biopsy of three young patients diagnosed on clinical examination as having BCC, who were found on histological examination to have trichoepithelioma. Whilst it may be possible to distinguish the features of trichoepithelioma in incisional biopsy specimens on morphological grounds alone it is often difficult, and immunohistochemical staining, to delineate the features of the basement membrane, provides useful additional information in the histological diagnosis. As trichoepithelioma is more common in the young it should be considered in the differential diagnosis in young patients presenting with BCC-like lesions of the periocular tissues. This subgroup of patients should have incisional biopsy carried out, and if the diagnosis of trichoepithelioma is confirmed the lesion may be excised with a small margin of healthy tissue, thereby facilitating surgical repair.