Shave biopsy revealed a trichilemmoma. These benign growths were first described more than 50 years ago and present histopathologically as a lobular epidermal neoplasm containing vacuolated cells and course hyaline granules with differentiation toward the outer root sheath of the hair follicle.1 Clinically, trichilemmoma presents as a smooth or verrucoid flesh-colored solitary papule on the face. Some lesions have been linked to infection with the human papilloma virus.2
Multiple trichilemmomas may indicate Cowden disease, a rare familial disease associated with cancers of the breast, thyroid, or gastrointestinal track. This autosomal dominant condition was first identified in 1963.3 Underlying this disorder are mutations of the PTEN tumor suppressor gene.4 As per screening guidelines established by the National Comprehensive Cancer Network,5 individuals with PTEN mutations should have baseline thyroid ultrasound scan, mammography, and endoscopic evaluation, along with genetic counselling and family screening.
Dr Schleicher is director of the DermDox Center for Dermatology, as well as an associate professor of medicine at the Commonwealth Medical College and a Clinical Instructor of dermatology at Arcadia University and Kings College.
- Headington JT, French AJ. Primary neoplasms of the hair follicle. Histogenesis and classification. Arch Dermatol. 1962;86:430-441.
- Rohwedder A, Keminer O, Hendricks C, Schaller J. Detection of HPV DNA in trichilemmomas by polymerase chain reaction. J Med Virol. 1997;51:119-125.
- Lloyd KM 2nd, Dennis M. Cowden’s disease. A possible new symptom complex with multiple system involvement. Ann Intern Med. 1963;58:136-142.
- Stambolic V, Suzuki A, de la Pompa, et al. Negative regulation of PKB/Akt-dependent cell survival by the tumor suppressor PTEN. Cell 1998;95:29-39.
- Eng C. Will the real Cowden syndrome please stand up: revised diagnostic criteria. J Med Genet. 2000;37:828-830.