CLEAR CELL ACANTHOMA: CLINICAL AND DERMATOSCOPIC CHARACTERISTICS

Abstract

In the article are presented three cases of clear cell acanthoma, their dermatoscopic characteristics and correlation with histological picture. Clear cell acanthoma is benign epidermal lesion initially described as neoplastic which some authors now regard to as a reactive dermatosis. These tumors clinically develop in middle-aged to elderly individuals as an asymptomatic lesion and typically present as a nodule or small plaque with slow and well-defined growth located mainly on the lower limbs. Despite the fact that clear cell acanthoma has a non-specific clinical appearance and may be mistaken with a number of other dermatoses, it has very specific and easy to recognize dermatoscopic features referring to many linear or curvilinear glomerular and dotted vessels arranged in a linear necklace-like arrangement called “ string of pearls”. In pathology images were seen acanthotic epidermis containing larger than usual keratinocytes (~2x normal epidermal keratinocytes), well demarcated from adjacent epidermis, as well as hypergranulosis, minimal nuclear pleomorphism, and dilated tortuous vessels within the dermal papillae, running vertically. About dermoscopic-pathologic correlation, the ‘string of pearls’ corresponds to the capillaries oriented perpendicular within the elongated dermal papillae.