Meaning of Cowden disease: An inherited condition that scatters benign growths through many organs and raises the lifetime risk of several cancers.

Definition of Cowden disease

Cowden disease is an inherited condition marked by numerous benign growths called hamartomas in the skin, mouth, thyroid, breast, bowel and elsewhere. Most cases trace to a fault in the PTEN gene, which normally restrains cell growth. A large head circumference and small warty bumps around the mouth and nose are typical, and the risk of breast, thyroid, uterine and kidney cancer is increased.

What is going wrong in the cells?

The PTEN gene acts as a brake on a signaling pathway that tells cells to grow and to resist dying. One working copy is inherited from each parent. People with this condition are born with one faulty copy in every cell, so the brake is already half released, and tissues respond by producing disorganized overgrowths. A hamartoma is exactly that: a jumble of the cell types that belong in the organ, growing in the wrong proportion and arrangement, without being cancer. The pattern is inherited in a dominant fashion, meaning a parent with the fault has an even chance of passing it to each child, though a substantial share of cases arise new in an individual.

What does it look like?

FeatureDetail
Skin around mouth and noseSmall warty bumps, present in most adults with the condition
Mouth liningA cobblestone appearance of the gums and tongue
Head sizeLarger than average, often from early childhood
ThyroidGoiter and multiple nodules
BowelMultiple polyps of mixed types

What cancers is it associated with?

The lifetime risk of breast cancer in affected women is substantially raised and cases occur younger than usual. Thyroid cancer, typically the follicular type, is the next best recognized association, and cancers of the uterine lining, kidney and colon occur more often than expected. Because of this, surveillance programs beginning in early adult life are standard practice for people with a confirmed diagnosis, and confirming the gene fault allows relatives to be tested. The condition also overlaps with other PTEN related syndromes described under different names, and all are now grouped together as PTEN hamartoma tumor syndrome.

How is it recognized?

The combination of a large head, the warty facial bumps and a thyroid or breast problem in the same person is the classic trigger for testing. Diagnostic criteria weigh major features such as breast and thyroid disease against minor ones, and a blood test for the PTEN fault confirms it in most but not all people who meet those criteria.

Also known as

Cowden syndromemultiple hamartoma syndromePTEN hamartoma tumor syndrome

Used in a sentence

Genetic testing after multiple thyroid nodules and macrocephaly confirmed Cowden disease.

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Good to know

Cowden disease, Bannayan-Riley-Ruvalcaba syndrome and related conditions are now grouped as PTEN hamartoma tumor syndrome, and a confirmed gene fault has implications for blood relatives.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.