What is it?

Cowden syndrome is an autosomal dominant inherited condition characterized by benign overgrowths called hamartomas as well as an increased lifetime risk of breast, thyroid, uterine, and other cancers. It is often underdiagnosed due to variability in disease presentation, but 99% of patients report mucocutaneous symptoms by age 20–29. Despite some considering it a primarily dermatologic condition, Cowden's syndrome is a multi-system disorder that also includes neurodevelopmental disorders such as macrocephaly.

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Additional names

This group contains additional names:
- Cowdens Syndrome

Signs & symptoms

As Cowden's disease is a multi-system disorder, the physical manifestations are broken down by organ system:
* Skin- Adolescent patients affected with Cowden syndrome develop characteristic lesions called trichilemmomas, which typically develop on the face, and verrucous papules around the mouth and on the ears. Oral papillomas are also common.
* Thyroid- Two thirds of patients have thyroid disorders, and these typically include benign follicular adenomas or multinodular goiter of the thyroid.
* Female and Male Genitourinary- Females have an elevated risk of developing endometrial cancers, which is highest for those under the age of 50.
* Gastrointestinal- Polyps are extremely common as they are found in about 95% of Cowden syndrome patients undergoing a colonoscopy. They are numerous ranging from a few to hundreds, usually of the hamartomatous subtype, and distributed across the colon as well as other areas within the gastrointestinal tract.
* Breast- Females are at an increased risk of developing breast cancer, which is the most common malignancy observed in Cowden's patients.
* Central Nervous System- Macrocephaly is observed in 84% of patients with Cowden syndrome. It typically occurs due to an abnormally enlarged brain, or megalencephaly. Patients may also exhibit dolichocephaly.


The revised clinical criteria for the diagnosis of Cowden's syndrome for an individual is dependent on either one of the following:
* 3 major criteria are met or more that must include macrocephaly, Lhermitte-Duclos, or GI hamartomas
* two major and three minor criteria.
The major and minor criteria are listed below:
Major criteria:
* Breast cancer
* Endometrial cancer (epithelial)
* Thyroid cancer (follicular)
* Gastrointestinal hamartomas
* Lhermitte-Duclos disease (adult)
* Macrocephaly
* Macular pigmentation of the glans penis
* Multiple mucocutaneous lesions (any of the following):
* Multiple trichilemmomas
* Acral keratoses palmoplantar keratotic pits and/or acral hyperkeratotic papules)
* Mucocutaneous neuromas
* Oral papillomas (particularly on tongue and gingiva), multiple OR biopsy proven OR dermatologist diagnosed

Minor criteria:
* Autism spectrum disorder
* Colon cancer
* Esophageal glycogenic acanthosis
* Lipomas
* intellectual disability
* Renal cell carcinoma
* Testicular lipomatosis
* Thyroid cancer (papillary or follicular variant of papillary)
* Thyroid structural lesions (e.g., adenoma, multinodular goiter)
* Vascular anomalies (including multiple intracranial developmental venous anomalies)


Malignancies that occur in Cowden syndrome are usually treated in the same fashion as those that occur sporadically in patients without a hereditary cancer syndrome. Two notable exceptions are breast and thyroid cancer. In Cowden syndrome patients with a first-time diagnosis of breast cancer, treatment with mastectomy of the involved breast as well as prophylactic mastectomy of the uninvolved contralateral breast should be considered. In the setting of thyroid cancer or a follicular adenoma, a total thyroidectomy is recommended even in cases where it appears that only one lobe of the thyroid is affected. This is due to the high likelihood of recurrence as well as the difficulty in distinguishing a benign from malignant growth with a hemithyroidectomy alone.
The benign mucocutaneous lesions observed in Cowden syndrome are typically not treated unless they become symptomatic or disfiguring. If this occurs, numerous treatment options, including topical agents, cryosurgery, curettage, laser ablation, and excision, may be utilized.

☝️ This is not a substitute for professional medical advice. Please consult with your physician before making any medical decision.

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