A case of focal acantholytic dyskeratosis occurring on both the lip and the anal canal.

Focal acantholytic dyskeratosis has a distinctive histological pattern that is associated with various clinical expressions. It rarely occurs on the lip or the perianal area. We report a patient with focal acantholytic dyskeratosis occurring on both the upper lip and the anal canal. Histopathologically, the lesions showed hyperkeratosis, suprabasilar clefting, epidermal acantholysis and dyskeratosis. This case represents the first report of a focal acantholytic dyskeratosis occurring on both the lip and the anal canal.