[Perineural invasion in keratoacanthoma (author's transl)].

Perineural tumoral invasion, usually considered as an histological sign of malignancy, may be seen in clinically and histological typical keratoacanthoma in every phase of evolution. The authors present 8 cases, among a collection of almost 300 keratoacanthomas, localized on the face, 3 in the proliferative phase, 3 at a state of maturation and 2 in plain regression. Sometimes perineural invasion is associated with other cellular anomalies and infiltration of the muscular layers. All the lesions were chirurgically excised without recurrence after a 4 months to 3 years follow-up. Perineural tumoral invasion may be considered as an image of pseudo-malignancy.