Friday Pop Quiz #26

skin growthAnswer:C: Classic phenotypic features of this disease include all of the following features except trichoepitheliomas.

This patient has Cowden disease. Biopsy of one of her facial papules was consistent with a trichilemmoma. Cowden disease is part of the PTEN hamartoma tumor syndrome that also includes Bannayan-Riley-Ruvalcaba syndrome, SOLAMEN syndrome (segmental overgrowth, lipomatosis, arteriovenous malformation, and epidermal nevus), and Lhermitte-Duclos disease. Cowden disease is an uncommon tumor syndrome due to an autosomal dominant mutation with incomplete penetrance in the PTEN gene, a tumor suppressor. The skin is involved in almost all cases of Cowden disease.

Cowden disease has many cutaneous findings including trichilemmomas, acral keratoses on the dorsal hands and feet, palmoplantar keratoses, oral mucosal papillomatosis, lipomas, hemangiomas, neuromas, lentigines, sclerotic fibromas and macrocephaly. Cowden disease is associated with multiple tumors including breast carcinoma and fibroadenomas, thyroid carcinoma and benign adenomas, endometrial cancer, ovarian cysts, leiomyomas, renal cell cancer, colorectal cancer and hamartomas and melanoma. Once Cowden disease is recognized it is important to initiate cancer surveillance.

Trichoepitheliomas are pink papules usually on the face that appear clinically similar to trichilemmoma. Trichoepitheliomas are associated with several autosomal dominant disorders including Brooke-Spiegler, Rombo, and Bazex-Dupré-Christol syndrome.


Eng C. PTEN: one gene, many syndromes. Hum Mutat. 2003; 22(3):183-98.

Hobert JA, Eng C. PTEN hamartoma tumor syndrome: an overview. Genet Med. 2009; 11(10):687-94.

Pilarski R. Cowden syndrome: a critical review of the clinical literature. J Genet Couns. 2009; 18(1):13-27.

Pilarski R, Burt R, Kohlman W, et al. Cowden syndrome and the PTEN hamartoma tumor syndrome: systematic review and revised diagnostic criteria. J Natl Cancer Inst. 2013; 105:1607.

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