Perineural Invasion in Basal Cell Carcinoma
Posted: Wednesday, August 12, 2020
Based on experience from an Australian center, perineural invasion is present more frequently in patients with basal cell carcinoma who have an increased number of infiltrative cells within their tumor mass, higher microscopic tumor diameter, deeper tumor invasion, and multiple cases of basal cell cancer. These findings were reported by John H. Pyne, MBBS, PhD, of the University of New South Wales, Australia, and colleagues in the Journal of Cutaneous Pathology.
Researchers collected 3,005 full excision samples from patients with basal cell carcinoma from 2016 to 2018 at a private practice in Sydney, Australia. Each sample underwent histopathologic examination and was screened for perineural invasion, which was defined as malignancy basaloid cells found within the perineural space but outside the tumor mass.
Perineural invasion was not found in any superficial, superficial combined with nodular, or nodular-alone subtypes of basal cell carcinoma. However, perineural invasion was noted in 7.4% of aggressive cases among men and in 5.2% of aggressive cases in women. When the percentage of tumor mass of infiltrative basal cell carcinoma increased to a level above 90%, there was a substantial increase in the presence of perineural invasion. Cases without perineural invasion had an average depth of invasion of 1.0 mm, compared with 2.3 mm for cases with invasion. The diameters of the nerves affected by perineural invasion ranged from 0.01 to 2.00 mm in men and from 0.02 to 0.04 mm in women.
In addition, there were 370 patients who had two basal cell carcinomas on exam, accounting for 47.5% of all perineural invasion cases. There were an additional 214 patients with three or more basal cell carcinoma cases, accounting for the remaining 52.5% of all perineural invasion cases. Perineural invasion was not seen on any patient who had just one case of basal cell carcinoma.
Disclosure: The authors reported no conflicts of interest.