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PTEN- Cowden Syndrome

Cowden syndrome (CS)

CS is characterized by multiple hamartomas and an increased risk of benign and cancerous tumors of the breast, thyroid, and uterus. Most individuals with CS will develop their first symptom before the age of 30. The features most frequently associated with CS are skin or mucosal findings, including small flesh-colored bumps in a hair follicle (trichilemommas), small wart-like growths (papillomatous papules), and acral and plantar keratoses. These features are considered pathognomonic, meaning they are defining characteristics of the condition. CS is also associated with a large head size (macrocephaly) and benign fatty and fibrous tumors (lipomas and fibromas).  There is a 25-50% lifetime chance of developing breast cancer in females with CS. The chance of developing uterine (women) and thyroid (men and women) cancers may be up to 10%. Skin cancers, renal cell carcinoma, and brain tumors as well as vascular malformations affecting any organ are occasionally seen in individuals with CS. Hamartomatous and/or adenomatous polyps of the small and large intestine may also occur. While precise estimates are not available, it is believed that the risk for colorectal cancer is moderately increased. A rare central nervous system tumor, cerebellar dysplastic gangliocytoma (Lhermitte-Dulcos disease), is also found in CS and considered pathognomonic.  Furthermore, learning disabilities, autism or other pervasive developmental disorders can sometimes be associated with CS.

Cowden syndrome is an inherited condition most commonly caused by mutations in the PTEN gene. Mutations in this gene are inherited in an autosomal dominant manner, meaning each first degree relative (parent, child, and sibling) of an individual with this condition has a 50% chance of inheriting the disease causing mutation.

The most serious consequences of Cowden syndrome relate to the increased risk of breast, thyroid, endometrial and to a lesser extent renal cancers. The mucocutaneous features of Cowden syndrome are not usually life-threatening, but should be evaluated regularly for changes in growth.


Genetics Home Reference 

PTEN Hamartoma Tumor Syndrome:  

The Children's Hospital of Philadelphia