Multiple tumour presentation of trichilemmal carcinoma.

Trichilemmal carcinoma is a rare skin tumour occurring in the sun-exposed areas of the elderly. It originates from the external root sheath of the hair follicle and is the malignant form of the trichilemmoma. Clinically, it may be mistaken for a squamous cell carcinoma, basal cell carcinoma, nodular melanoma or keratoacanthoma. It is distinct from the proliferating trichilemmal tumour. Trichilemmal carcinoma is usually a solitary lesion and an extensive literature search revealed no previously reported cases of multiple tumour presentation. We describe a case of trichilemmal carcinoma arising from three distinct sites in the same patient and discuss the differential diagnoses, histological features and probable aetiology of this rare tumour. Copyright 1999 The British Association of Plastic Surgeons.