Pigmented trichoblastoma with sebaceous hyperplasia.

ABSTRACT

Trichoblastoma is a rare benign trichogenic tumour with epithelial and mesenchymal components recapitulating the germinal hair bulb and associated mesenchyme. A 50- year- old male patient presented with slowly enlarging circumscribed solid nodule measuring 4x3x4.5 cm over the tip of the nose. Microscopy of tumour revealed nodular tumour spanning the entire dermis with collection of mesenchymal cells resembling follicular papilla. Areas of pigmentation and sebaceous hyperplasia were noted. There is a need for differentiation of this tumor which is benign, from other pigmented tumors having basaloid arrangement of cells such as basal cell carcinoma.