Introduction

: Trichoblastoma is a neoplasm that is not clinically suspected due to its low frequency but must be differentiated from basal cell carcinoma through histopathological study.

Aim

: To report an extremely rare tumor that occurs in places where it is common to see basal cell carcinomas.

Clinical case

: The case of a 34-year-old patient is presented, who showed a nodule of firm consistency and defined edges on the right side of the forehead. In the histological evaluation a well-circumscribed hypodermal nodule was found consisting of masses and nests of large basaloid cells with an ovoid nucleus and visible nucleolus with peripheral palisade and some rudimentary follicles. Given these findings, the differential diagnosis with basal cell carcinoma and trichogerminoma was raised, since these neoplasms have common elements. Immunohistochemistry showed that tumor cells were positive in a higher or lesser percentage for: p63, p53, CK20, Bcl2 and CD10.

Conclusions

: Diagnosingatrichoblastoma is a challenge since it has characteristics similar to basal cell carcinoma and other benign follicular tumors such as trichogerminoma, so it is necessary to interrelate the histomorphological findings with the immunohistochemical results.