[Management of basal cell carcinoma with perineural invasion].

The presence of perineural invasion in skin tumors constitutes a major risk factor for local recurrence.1-3 Perineural invasion is not a common finding in basal cell carcinomas, with an estimated incidence that, depending on the series, varies between 0.17%2 and 3.8%.4 The frequency is higher in more aggressive histological subtypes and in recurrent tumors.1,2,4,5 The patient was a 69-year-old woman who consulted for an 8-month history of a slow-growing, asymptomatic lesion on the right ala nasi. On examination there was a slightly elevated, infiltrated plaque of 1.2 cm in diameter, with poorly defined borders, a smooth, shiny surface, and superficial telangiectasias (Figure 1A). A previous biopsy of the lesion at another center led to a histological diagnosis of superficial and morpheaform basal cell carcinoma with perineural invasion. The patient had no medical or surgical history of interest and, given the results of the biopsy, the lesion was completely excised using Mohs surgery. Two stages were required to achieve disease-free margins (Figure 2A). In view of the presence of perineural invasion, an additional Mohs stage was performed (Figure 1B), also with negative margins. However, subsequent study of paraffin-embedded surgical specimens from each stage, prepared after taking frozen sections for evaluation of the margins, showed no tumor infiltration in the specimen corresponding to the second stage but the presence of tumor tissue in the third stage (Figure 2B). Perineural invasion enables a tumor to spread to sites well away from the primary site and to establish References