Porokeratosis of the lower lip.

The porokeratoses are defined as specific disorders of keratinization that are histologically characterised by the presence of a dense, parakeratotic column, well-circumscribed from the rest of the corneocytes, known as the cornoid lamella. In this article, we report two cases of porokeratosis of the lower lip, drawing attention to the unusual site. We also emphasize the clinical appearance of these lesions, which may easily be misdiagnosed if not examined correctly. As a consequence of this misdiagnosis, the prevalence of these lesions is probably greater than at present estimated. Moreover, a good response to cryotherapy is shown.