Incidence of perineural invasion in histologically aggressive types of basal cell carcinoma

Basal cell carcinoma is generally an indolent form of skin cancer. Morpheaf orm, infiltrative, and sclerosing types are more aggressive tumors. The inc idence of perineural invasion in aggressive types of basal cell carcinoma h as not been previously described. We studied aggressive basal cell carcinom as for the presence of perineural invasion. Between 1995 and 1998, the hist opathologic diagnosis of basal cell carcinoma was made on 5,097 specimens a t Dartmouth-Hitchcock Medical Center. Of this total, 507 were classified as sclerosing, infiltrative, or morpheaform. Perineural invasion was found in 15 of the 507 cases. Of these 15 cases, 12 were from the face, and 3 from the back: 13 were recurrent, and 2 were primary lesions. The mean age of pa tients at diagnosis was 71 years. We found 9.9% of all basal cell carcinoma s at our institution to be aggressive types. We found an incidence of perin eural invasion of 3% in the aggressive basal cell carcinoma types. This inc idence approaches that reported by others for cutaneous squamous cell carci nomas.