Proliferating Trichilemmal Tumor of the Auricula: A Very Rare Locus

Abstract

Proliferating trichilemmal tumor (PTT) is a rare but morphologically characteristic tumor, derived from the external root sheath. They are commonly localized as a solitary lesion on the scalp. They rarely occur in other regions. PTTs generally behave in a benign fashion, up to 20% of the lesions may undergo malignant transformation into squamous carcinoma. We present an elderly woman with a cystic swelling on the crus of auricular helix diagnosed as PTT. To our knowledge, this is the first case in the English literature, of PTT of the auricula.