Proliferating Trichilemmal Tumor in Uncommon Site

ABSTRACT

The proliferating trichilemmal tumor (PTT) is a rare, usually benign, tumor arising from the outer root sheath of the hair follicle. The usual clinical presentation is in a form of subcutaneous nodule in the scalp of elderly woman. Histopathologically, characteristic proliferation of the outer root sheath epithelium such as trichilemmal keratinization and nodular organization is observed as well as cellular atypia which may lead to impression of malignancy. The author report a case of proliferating trichilemmal tumor arisen in the thigh of a 24-year-old male within duration of 3 months which is quite an unusual clinical presentation.