[Skin adnexal tumors with follicular differentiation].

Skin adnexal tumors with predominantly follicular differentiation represent a clinicopathological heterogeneous group of neoplasms and are classified according to the cytologically achieved differentiation of the follicular compartment. Given the complex structure of non-neoplastic hair follicles it is not surprising to find varying differentiations in neoplasms and there are overlapping clinicopathological features between the established entities. The use of immunohistochemical staining has only a limited value in the diagnosis of follicular neoplasms.