Dermatológia pre prax 1/2011

Basal cell carcinoma (BCC) of the skin with adnexal differentiation – analysis od diagnosed cases and review of the literature

Basal cell carcinoma (BCC) of the skin is currently the most common malignancy in humans. Histomorphologically, it manifests relatively marked structural variability. BCC with adnexal differentiation represents one of its rare histological types. The aim of our study was to assess prevalence and individual pathological findings of BCC with adnexal differentiation diagnosed during 4-years period. Selected group consisted of 38 tumors from 36 patients (16 men, 20 women), mean age 66.2 years. This variety of BCC represented 5,8 % of all diagnosed cases in observed period. Lesions occurred most frequently on the scalp (n = 8), eyelids and adjacent periocular regions (n = 7), nose and paranasal regions (n = 6), and cheeks (n = 5). Less frequently affected areas included the auricles and periauricular regions (n = 3), forehead (n = 3), extremities (n = 3), trunk (n = 2), and neck (n = 1). Histomorphologically, 20 cases represented BCC with „pure“ trichoepithelial (follicular) differentiation, but focal trichoepithelial growth features also occurred in the majority of other nodular and superficial BCCs. This form of differentiation manifested as branching nests of basaloid cells, which showed signs of peripheral palisades and stromal retraction phenomenon. There was also present abrupt keratinisation with ductal and cystic spaces. Proliferative activity of neoplastic cells of this component ranged 2 – 45 % (mean value 20.9 %). In one woman, we diagnosed two nodular BCCs with sebaceous differentiation characterised by a presence of clusters of vacuolised sebocytes. There was visible partial clear cells differentiation of tumorous cells in three BCCs. The adnexal differentiation of BCC has clinically no prognostic impact, however, in a routine biopsy practice, distinction between this tumor variant and true adnexal skin neoplasias may be difficult and requires more complex approach in differential diagnosis. From a scientific point of view, studies of these lesions could provide more detailed information about histogenetic origin and pathogenesis not only of BCC, but also another related oncological skin disorders.

Keywords: basal cell carcinoma, adnexal differentiation