Two case reports of columnar dyskeratosis, an unusual keratinisation disorder.

Keratinisation disorders with distinctive histopathological patterns are few in number. We describe two men with unusual dermatosis, characterised by a distinctive pattern of focal dyskeratosis. Both men suffered from generalised dermatosis formed by verrucous red-brown plaques. Repeated skin biopsies showed the same histopathological pattern with foci of vertically oriented dyskeratotic cells. The dyskeratotic cells on the level of the stratum spinosum and granulosum were positive for AE1/AE3, CK-HW, CK-LS and CK116 immunostaining. PCR for HPV was negative. The similar clinical appearance of skin lesions in both patients together with their identical histopathological pictures seems to represent a unique clinicopathological condition that we believe is best described by the term 'columnar dyskeratosis'. 2010 S. Karger AG, Basel.