Hair Matrix Tumors:
Tumors of hair matrix type have the cytologic features of hair matrix cells; the cell have basophilic cytoplasms and round nuclei with marginated chromatin. They may be mistaken for common basal cell carcinomas. The so-called trichoblastoma is an example but this is a heterogeneous category; the descriptions in the literature have been variable. The most common form of trichoblastoma has the features of a tumor that has also been reported as giant trichoepithelioma. The hair matrix tumor is a lesion lacking evidence of both trichogenesis and patterns of hair sheath differentiation; it is a primitive tumor of uncertain biologic potential. In our experience with examples of this lesion at Charity Hospital of New Orleans, LA, the lesion is more common in dark-skinned races. An example with metastases has not been documented but patterns of common basal cell carcinoma have been encountered in rare examples.
The text (HOME) was prepared and submitted for publication but 2 reviewers interpreted the material as representative of common basal cell carcinomas and the manuscript was rejected. The glass slides and photographs were lost in the aftermath of Katrina. The text is presented on this Site on this Section. Examples of the histologic patterns can be found on the Section, Follicular Diseases.