Abstract
BCC is the most common neoplasm encountered in humans. It is also the most common indication for Mohs micrographic surgery (MMS). MMS has a 99% 5-year cure rate for primary BCCs. For recurrent BCCs, the 5-year cure rate is 96%. Infiltrating, micronodular, and morpheaform subtypes are considered more aggressive forms of BCC, and MMS should be the primary treatment for those subtypes. Inflammatory cells, hair follicles, and folliculocentric basaloid proliferations are benign conditions that can resemble BCC when using horizontal frozen sections. Malignant processes such as metastatic breast cancer, ameloblastoma, cloacogenic carcinoma, eccrine spiradenoma, pilomatricomas, and trichoepitheliomas can also mimic BCC. Additionally, BCC may differentiate to simulate many structures such as hair follicles, sweat glands, and sebaceous glands. The evidence behind MMS for BCC is strong with studies backed by a high number of patients along with very low recurrence rates. It is especially well suited for aggressive histological subtypes of BCC and for BCCs in anatomical regions where tissue conservation is paramount.