ATLAS OF SKIN DISEASES

Clonal Seborrheic Keratosis is a rare variant of Seborrheic Keratosis, which is difficult for diagnosis, both clinically and histopathologically. Clinically, this form can be indistinguishable from classical Seborrheic keratosis, but it can also appear as a warty, unpigmented pink asymptomatic plaque, resembling Bowen's disease. To confirm the diagnosis, biopsy and histopathological examination are necessary. Histopathological diagnosis is also accompanied with certain difficulties due to the presence of signs, both characteristic of Seborrheic keratosis, and for skin cancer: basal cell carcinoma, Bowen's disease and others. Immunohistochemical markers CK10, Ki-67 are useful in unclear cases.