Case Number : Case 1318 - 13 July Posted By: Guest

Verrucous trichilemmal cyst with epithelial proliferation. I will ask for serial sections to verify possible dysplastic changes.

Squamous cell carcinoma arising in a proliferating pilar (trichilemmal) cyst.

Proliferating trichilemmal tumor.

Here's my diagnosis:

[b]-- PROLIFERATIVE TRICHOLEMMAL CYSTIC CARCINOMA[/b]
[indent=1][b]COMMENT:[/b] The differential diagnosis is with proliferative tricholemmal cystic acanthoma, the benign analog to this lesion. Some use the term proliferative tricholemmal cyst to refer to these types of lesions, but I think that designation really doesn't capture the broad spectrum of changes that can occur in these lesions. Most of them tend to act like low grade carcinomas, but some of them have been more aggressive and published in the literature (see references below). In any event, I don't see any evidence of the lesion involving the margins of resection, and adipose tissue is identified deep.[/indent]


[indent=1]1. Sau P, Graham JH, Helwig EB. Proliferating epithelial cysts. Clinicopathological analysis of 96 cases. J Cutan Pathol. 1995 Oct;22(5):394-406. PubMed PMID: 8594071.[/indent]

[indent=1]2. Ackerman AB, Mones JM. Proliferating tricholemmal cystic carcinoma (Revision of chapter XXV of the volume titled Neoplasms with Follicular Differentiation, 2nd edition by Ackerman, Reddy, and Soyer, Ardor Scribendi, Ltd., 2001). In: Dermatopathol Pract Concept 2006; 12:2.[/indent]