Nevus sebaceus of Jadassohn is a congenital tumour affecting the scalp and face. It is usually presented as a pigmented patch or plaque. It is a complex cutaneous hamartoma which involves pilosebaceous follicle, epidermis and adnexal structures. Tumours that arise from nevus sebaceous are basal cell carcinoma, syringocystadenoma papilliferum, trichoblastoma and hidradenoma. The progression and frequency of the tumour increase with the age. Here we present a case of pigmented trichoblastoma over the external nose. It was a case of an elderly woman presenting with a painless swelling over the external nose which was soft, non-tender and with well defined margins.
Keywords: Nevus sebaceous of Jadassohn; Trichoepithelioma; Tumour.