Proliferating trichilemmal tumour: a case report with review of literature.

Proliferating trichilemmal tumour is a solid-cystic neoplasm that shows trichilemmal differentiation similar to that of the isthmus of the hair follicle histologically characteristed by the presence of trichilemmal keratinization. Proliferating Trichilemmal Tumour (PTT) appears mainly in elderly women and is in general a solitary lesion on the scalp. Proliferating trichilemmal tumours generally have a benign clinical course, and a clinical differentiation from squamous cell carcinoma is often difficult. We report a case of PTT in a 30 year old man presenting as a solitary 10x8 cm ulcerated nodule on the scalp since 3 months clinically resembled a malignant tumour. The therapeutic approach is surgical removal with a wide clear margin.

A Case of Trichilemmal Horn / 대한피부과학회지

Trichilemmal horn is a unique, uncommon epidermal tumor that exhibits a hard protruding hyperkeratotic plaque. Histologically, it is characterized by striking orthokeratotic hyperkeratosis and verrucous hyperplasia of the epidermis without the formation of a granular cell layer. The acanthotic epidermis shows an epithelial lobule, composed of pale staining keratinocytes, that is contiguous with the overlying epithelium and extended into the dermis. We herein report a case of trichilemmal horn developing on the right temporal area of a 80-year-old woman, which shows typical clinical and histopathological features.

Two Cases of Proliferating Trichilemmal Cyst / 대한피부과학회지

We report two cases of proliferating trichilemmal cyst in a 61-ear-old woman and a 44-year-old woman who had a solitary tumor, on the left temporal area of the scalp and right flank, respectively. Histologically, the tumors were localized in the dermis and corisised of multilobulated cysts. The cyst walls were composed of liquamous epithelium showing trichilemmhl keratinization. Some of the cells had clear cytoplasm and were positive on PAS staining. Individiial cell keratinization, mild nuclear atypia were also found in the cyst walls. For the treatment, surgical excision was performed with sufficiert margin.

Proliferating Trichilemmal Tumor: Report of four cases

Proliferating trichilemmal tumor is relatively rare, and is generally considered to be a benign tumor that can be histologically mistaken for well-differentiated squamous cell carcinoma. The proliferating trichilemmal tumor is thought to be a tumor with differentiation toward the hair structure because the characteristic trichilemmal keratinization in this tumor is analogous to that of the outer root sheath of anagen hair or the trichilemmal sac surrounding catagen hair. We report four cases of proliferating trichilemmal tumor removed by surgical excision.