PTEN Mutation Hamartoma Tumor Syndrome

PTEN Mutation Hamartoma Tumor Syndrome (PHTS) is caused by a genetic abnormality that leads to uncontrolled growth of different tissues in various parts of the body. It is better known by one of the clinical syndromes described before the gene mutation was discovered: Cowden syndrome or Bannayan-Riley-Ruvacalba syndrome.

Signs and Symptoms

Characteristics may include:

• Macrocephaly (large head circumference)
• Malformed or abnormal blood vessels (vascular anomalies)
• Skin tags
• Freckles on the glans of the penis for boys
• Developmental delay or learning disabilities
• Thyroid nodules
• Colon polyps
• Predisposition to develop cancer at early age (thyroid, breast, uterine, endometrial, colon cancer etc.)

Common problems may include:

• Pain of the area affected by the vascular anomaly
• Limitation of mobility due to the vascular anomalies
• Bleeding from colon polyps
• Specific presentations related to each type of cancer

Genetics

The syndrome is caused by a mutation or deletion of PTEN gene. This can be identified from a blood sample of the patient. It is a germline mutation meaning that it is transmitted from generation to generation within the family. We usually recommend and offer genetic testing and counseling to the siblings and parents at least.

Diagnosis and Tests

Diagnosis and tests may consist of:

• Physical exam
• Blood work
• Colonoscopy for colon polyps
• Imaging
  • Doppler ultrasound to see if there are problems with the blood vessels and to screen for thyroid nodules

• Magnetic Resonance Imaging (MRI) for better visualization of vascular anomalies and of benign tumors that may develop
• Mammography starting at an earlier than usual age to detect early signs of breast cancer

Treatment

Management of PTEN Mutation Hamartoma Tumor Syndrome involves a multidisciplinary team.  Treatment goals include reducing the symptoms and providing cancer screening for the commonly associated cancers.

Care may include:

• Sclerotherapy or embolization – a solution is injected into the abnormal vessels to help make them shrink
• Surgical intervention to remove cosmetically or functionally disturbing benign growths (from the skin and occasionally from the mouth)
• Medical therapy with sirolimus – a medication that works on the genetic pathway that is not properly controlled due to the PTEN mutation
• All cancer management, if needed
• Psychology counseling – chronic condition with a high risk of cancer development early in life

Cancer Predisposition Screening

• Ultrasounds of the thyroid gland and biopsy of the nodules that become too large or suspicious of malignant transformation
• Screening for iron deficiency anemia caused by repeated bleeding from the colon polyps. If polyps are identified, colonoscopy may be performed at set intervals of time for monitoring and biopsy of large or atypical polyps
• Breast exam and early recommendation of mammograms for girls