A 67-year-old man presents to the dermatology clinic requesting removal of a growth on his right cheek. The lesion was first noted by the patient several months ago and has slowly increased in size. The patient denies itching or bleeding and has no prior history of skin cancer. He is a cigarette smoker and drinks in moderation. Examination of the lesion reveals a 0.4cm slightly erythematous papule; scattered seborrheic keratoses are noted on his back.
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A biopsy of the lesion revealed a desmoplastic tricholemmoma, an uncommon variant of tricholemmomas that is composed of epidermal tumor lobules containing glycogen-rich clear cells embedded within a fibrous stroma.1
Tricholemmomas are benign neoplasms that most commonly arise on the face of elderly individuals; the lesions tend to appear most often in the zone above the lip and chin.2 Most lesions are solitary and present as flesh-colored to pink dome-shaped papules measuring less than 0.5 cm in diameter.
The appearance of multiple lesions may be a sign of Cowden syndrome, an autosomal-dominant genodermatosis with variable penetrance that is associated with internal malignancies such as breast, thyroid, colon, and renal carcinoma.3 Most cases are associated with a germline mutation of the phosphatase and tensin homolog gene (PTEN), which has been deleted on chromosome 10.
The majority of lesions will stain positive for CD34.4 Lesions most commonly occur in men and may clinically resemble basal cell carcinoma.5
Dermoscopy may aid in the differential diagnosis, revealing peripheral crown vessels with pink and white central structureless areas.6 Malignant transformation of these lesions has not been reported and simple excision is curative.
Stephen Schleicher, MD, is director of the DermDox Dermatology Centers, associate professor of medicine at Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
1. Tellechea O, Reis JP, Baptista AP. Desmoplastic trichilemmoma. Am J Dermatopath. 1992;14(2):107-114. doi:10.1097/00000372-199204000-00004
2. Goldman L, Richfield DF. Tricholemmoma clinical lesions. Arch Dermatol. 1977;113(1):107-108. doi:10.1001/archderm.1977.01640010109019
3. Lopes S, Vide J, Moreira E, Azevedo F. Cowden syndrome: clinical case and a brief review. Dermatol Online J. 2017;23(8):13030/qt0023k3x0.
4. Zhong S, Wang L, Mei XL. Desmoplastic trichilemmoma of the scalp: case report and literature review of immunohistochemical staining features. J Int Med Res. 2019;47(8):3918-3925. doi:10.1177/0300060519859739
5. Sano DT, Yang JJ, Tebcherani AJ, Bazzo LA. A rare clinical presentation of desmoplastic trichilemmoma mimicking invasive carcinoma. An Bras Dermatol. 2014;89(5):796-798. doi:10.1590/abd1806-4841.20143095
6. Colon A, Gillihan R, Motaparthi K, Longo MI. Crown vessels of desmoplastic trichilemmoma: use of dermoscopy with pathological correlation. J Clin Aesthet Dermatol. 2020;13(6):46-47.