Clear Cell Acanthoma/Pseudolymphoma: Clinical­Dermatoscopic and Histological Correlation

Abstract

Results . Clear cell acanthoma is a rare benign epithelial tumor with unclear etiology. It is believed that the basis of its development is an impaired keratinocyte maturation. Some authors do not refer it to tumors, but consider that this is a local hyperplastic process. Clear cell acanthoma often develops in the elderly as a single node up to 2 cm in diameter, usually found on the lower extremities, most commonly on the legs. Differential diagnosis should be carried out with dermatofibroma, lichenoid keratosis, basalioma, pyogenic granuloma. Differential diagnosis with irritated seborrheic keratosis and non­pigmented melanoma is difficult. Dermatoscopic examination can be insufficient, the pathomorphological conclusion is necessary for the final diagnosis. The pseudo­lymphoma of the skin is a reactive dermatosis, resembling lymphoma both clinically and histologically, but has a benign course and a tendency to spon­ taneous regression, therefore, for a differential diagnosis, dermatoscopy and pathological examination are necessary. Two cases from own practice were presented in the work; clearly distinguished pink hemispherical nodes were observed in both patients. During the dermatoscopic examination, two different tumors were diagnosed ­ clear cell acanthomas and pseudolymphomas, in both cases the dermatoscopic indicators corresponded to the pathological conclusion. Conclusions. An overview of modern literature and clinical cases from our own practice suggests that clinically similar single infiltrative skin lesions can be identified by previous dermatological studies. Careful clinical and dermatological monitoring provides additional benefits for better recognition of skin tumors, although unclear cases require a pathomorphological