Cowden syndrome Q87.86

Autosomal-dominantly inherited genodermatosis(PTEN-hamartoma tumor syndrome/ PTEN= phosphatase and tensin homologue) with pathognomic mucocutaneous changes such as:

• facial tricholemmomas
• oral papillomatosis
• acral keratoses
• hamartous tumors of the mamma and thyroid gland
• polyps in the gastrointestinal tract.

The main diagnostic criteria include thyroid carcinomas, mammary and endometrial carcinomas, dysplastic gangliocytoma of the cerebellum, and macrocephaly(Lhermitte-Duclos syndrome).

Mutations of the PTEN1 tumor suppressor gene (phosphatase and tensin homolog gene) mapped to gene locus 10q23.3, with consecutive suppression of protein tyrosine phosphatase (PTEN), a protein that physiologically supports the onset of cell death. Suppression of PTEN protein thus stimulates cell proliferation and hamartoid growth.

Related syndromes in which PTEN germline mutations have also been found are Bannayan-Riley-Ruvalcaba syndrome and Proteus syndrome.

Main dermatological symptoms: Papular, centrofacial and acral lesions. Perioriferal and acral lentigines, pronounced papillomatosis of the oral mucosa and intestinal tract. Tricholemmomas, trichoepitheliomas of the face. More frequent lipomas, hemangiomas and vitiligo.

Extracutaneous manifestations: avian face, microstomy, hypoplasia of the upper and lower jaw, narrow nose, antimongoloid eyelid axis. Lingua plicata, tooth position anomalies. Multiple cysts in hyperplastic mammae, liver, thyroid gland and bones.

1. Bruce H et al (2009) Cutaneous manifestations of internal malignancy. Cancer J Clin 59: 73-98
2. Canadas LMC et al (2006) Multiple oral fibropapillomatosis as an initial manifestation of Cowden syndrome. Case report. Oral Medicine and Pathology 11: 319-324
3. Fistarol SK et al (2002) Cowden disease or multiple hamartoma syndrome--cutaneous clue to internal malignancy. Eur J Dermatol 12: 411-421
4. Fritsch P et al (1981) The multiple hamartoma syndrome (Cowden syndrome). Dermatologist 32: 285-291
5. Happle R et al (2002) Radiation-induced cutaneous hamartoma in a patient with Cowden syndrome. Clinical evidence for heterozygosity. dermatologist 53: 47-49
6. Lloyd KM, Dennis M (1963) Cowden's disease: A possible new symptom complex with multiple systemic involvement. Ann Internal Med 58: l36-142
7. Schaller J et al (2003) Identification of human papillomavirus DNA in cutaneous lesions of Cowden syndrome. Dermatology 207: 134-140
8. Vega A et al (2003) A Novel Loss-of-Function Mutation (N48K) in the PTEN genes in a Spanish patient with Cowden Disease. J Invest Dermatol 121: 1356-1359