Trichoepithelioma : Introduction
Trichoepithelioma is a hamartomatous lesion that can be multiple (usually familial) or solitary. Multiple Familial Trichoepithelioma (MFT): Inherited as an autosomal dominant condition with onset in puberty in the form of numerous 0.1 to 0.5 cm size skin-colored papules on the face in a symmetrical distribution. Other sites of involvement include scalp, neck, extremities, buttocks, and inguinal region. Ulceration is uncommon. Mutations in CYLD gene on 16q12-q13 have been found. Based on these findings, MFT is believed to be related to familial cylindromatosis and Brooke-Spiegler syndrome. Brooke-Spiegler Syndrome: An autosomal dominant condition characterized by multiple cylindromas, spiradenomas, multiple trichoepitheliomas, and milia. The penetrance is high but the clinical presentation varies widely. Skin lesions present in early adulthood. Cylindromas usually appear on scalp and can become quite large (turban tumor). The patients may develop other tumors as well, including trichoblastoma, cutaneous lymphadenoma, membranous-type basal cell adenoma (parotid), and cylindroma of breast. Rare cases of malignant transformation of cylindromas and trichoepitheliomas have been documented. Rombo Syndrome: Consists of multiple trichoepitheliomas, milia, vermiculate atrophy, basal cell carcinoma, vellous hair cysts, peripheral vasodilatation, and cyanosis. It is an autosomal dominant condition and skin lesions first appear in childhood. Solitary Trichoepithelioma: It presents as a flesh-colored nodule on face. Other sites include scalp, neck, back, genital areas, and extremities. Case History: This 24 year old female presented with numerous round to oval skin coloured, firm plaques and nodules measuring 2 to 6 mm, located over nose, naso-labial folds, malar region and extending into upper lip. She had noticed a few smaller nodules over nose in her childhood and they had been progressively increasing in size and number since then. There was positive history of similar lesions in her father. One of the lesions biopsied showed characteristic microscopic features of trichoepithelioma. Case courtesy of: Dr. Sanjay D. Deshmukh (Professor of Pathology) & Dr. Vishal A. Indurkar (Associate Professor of Dermatology), Dr. Vithalrao Vikhe Patil Medical College and Hospital, Ahmednagar, India.