The clinicopathological spectrum of trichoepitheliomas: a retrospective descriptive study

Trichoepithelioma (TE) is a benign adnexal neoplasm derived from basal cells in the hair follicle. Solitary TE occurs sporadically as opposed to the multiple familial variant that presents as an autosomal dominant genodermatosis. The solitary variant can be confused with basal cell carcinoma both clinically and histologically. Multiple familial TEs are a cosmetically disfiguring condition with limited satisfactory treatment options.

Skin biopsies diagnosed as TE from January 1, 2001, to December 31, 2011, were retrieved from the archives of the Division of Anatomical Pathology (University of Stellenbosch and National Health Laboratory Service, Cape Town, South Africa). Clinical and demographic data were retrieved from the patient records at Tygerberg Academic Hospital. Data of patients with solitary TE and multiple TE were compared.

Thirty-three biopsy specimens were collected from 30 patients. Twenty patients had solitary TE, nine patients had multiple TEs, and one patient had multiple linear TEs. Multiple TEs started to develop in patients at an average age of 17.3 years. Three patients in the study had tumoral TE with a diameter greater than 20 mm. One patient had TE associated with a basal cell carcinoma. Multiple TEs were commonly misdiagnosed clinically as tuberous sclerosis and showed a cribriform histopathological tumor pattern in 80% of cases as compared to only 10% of solitary TEs.

The current study was confined to a cohort of patients, in the Western Cape Province of South Africa, whose ethnic and geographic origins were not available. The extrapolation of findings from this study to the rest of the South African population may not be valid. A cribriform growth pattern occurs in the majority of cases of multiple TEs.