Perineural Invasion in the Absence of Malignancy: Report of Two Cases and Review of the Literature

Perineural invasion is usually associated with invasion of the perineural space by malignant tumors. In this report, we describe 2 cases of perineural infiltration by benign-appearing epithelial cells in the skin. One case concerns a tumor-free reexcision specimen of a basal cell carcinoma and the other one an ulceration at the outer ear, consistent with acanthoma fissuratum, without a history of a previous excision. This finding was interpreted as a reactive process with dislocation of epithelium from the overlying epidermis into the perineural space. © 2014 S. Karger AG, Basel