Pigmented trichoblastoma.

We report a case of trichogenic tumor with epithelial and mesenchymal components recapitulating the formation of hair germs. The epithelial lobules were highly pigmented and affected the full thickness of the dermis, extending into the subcutaneous fat. In addition, amyloid deposits were found within the epithelial lobules and in the stroma. The overall architecture was reminiscent of hair bulbs. Problems of differential diagnosis with other trichogenic tumors and pigmented tumors are discussed.