Fibroepithelioma of Pinkus

Basal cell carcinoma (BCC) is recently the most common cancer in humans characterized by several histopathological subtypes. Fibroepithelioma of Pinkus (FEP) is traditionally classified as a very rare variant of BCC, however, it manifests clinical and morphological differences that distinguish it from most other types BCCs. This study was performed to evaluate the incidence of FEP and clinical-pathological characteristics of patients diagnosed with this tumor. Four cases of primary FEP (3 females, 1 male, mean age 53.4 y) were analyzed retrospectively. The prevalence of FEP was 0.7 % of all diagnosed BCCs. Topographically, tumors were localized on the right brachium, right gluteal region, left mesogastrium, and right side of the abdomen. Histological examination showed typical anastomosing cords of basaloid cells extending from the overlying epidermis into the loose fibrous stroma in the dermis. Mitotic activity or significant cellular atypia, as well as sign of solar dermatosis were absent. Mean horizontal and vertical diameter of the lesions were 7.7 and 2.8 mm, retrospectively. We did not observe infiltration of deeper skin structures. All lesions were removed completely and classified as pathological stage pT1. Three cases manifested typical picture of a "pure" FEP, one lesion had partially a feature of nodular type BCC, too. Although FEP is conventionally considered as indolent BCC variant with a favorable clinical outcome, recent evidences also favors its classification as a form of trichoblastoma. This is appropriate example how some types of cutaneous tumors can overlap in terms of dignity and clinical-morphological characteristics. This should be taken into account in differential diagnosis and in predicting of biological behaviour of the individual tumors of the skin (Tab. 2, Fig. 3, Ref. 26).