Basal cell carcinoma with intraneural invasion.

Two cases of basal cell carcinoma had diffused infiltration that included not only perineural but endoneurial invasion. One patient presented with trigeminal neuralgia, and the other patient developed localized neuralgia when the tumor recurred. Nests and indian files of carcinoma cells were in the endoneurium, a region that anatomically is devoid of lymphatics. The involved nerves displayed axonal degeneration. Such intraneural invasion by basal cell carcinoma is very rare, even in the scelerosing variety of basal cell carcinoma.