Hemihypertrophy in Children

What are the signs and symptoms of hemihypertrophy?

The most noticeable sign of hemihypertrophy is that one side of the body is larger than the other. Many times, a leg or an arm will be longer or larger in circumference than the other. However, it isn't always obvious. Sometimes hemihypertrophy is hard to notice unless your child is laying down flat – this is called the "bed test" In other instances, you may notice a difference in their posture or gait (how they walk).

What tests are used to diagnose hemihypertrophy?

Hemihypertrophy is often associated with overgrowth syndromes such as Beckwith-Wiedemann syndrome, proteus syndrome, neurofibromatosis Type 1 and mosaic trisomy 8. It is also associated with vascular malformations such as Klippel-Trenaunay syndrome and megalencephaly-cutis marmorata telangiectatica congenital (CMTC).

At Children's Hospital Colorado, we first do genetic testing to identify if the condition is associated with another disease. For the test, we will need to get a DNA sample by swabbing the inside of the cheek or by taking a blood sample. Further testing and treatment will differ depending on if there is a second disease found during the genetic test.

Screening for tumors related to hemihypertrophy

Due to the increased risk of tumors, we also recommend screening for all children with hemihypertrophy. For tumor screening, we use imaging tests such as ultrasounds and magnetic resonance imaging (MRI).

If the genetic testing reveals no other associated syndromes, but your child's doctor still observes asymmetrical growth, they will most likely be diagnosed with isolated hemihypertrophy.

How is hemihypertrophy treated?

Although children with hemihypertrophy can develop problems in their bones and joints, most of the treatment focuses on combating the increased risk of tumors.

Wilms tumors are one of types of tumors that are more commonly linked to hemihypertrophy. The Wilms tumor usually develops before the age of 5, but some children can develop them later.

Children with hemihypertrophy also have an increased risk of developing a liver cancer called hepatoblastoma. Most hepatoblastomas develop by 2 years old.

The importance of regular cancer screenings

Given the importance of early detection, all children with hemihypertrophy should receive cancer screenings, which consists of an abdominal ultrasound every 3 to 4 months until the age of 10.

If we detect a developing Wilms tumor, we usually start treatment with a low dosage of chemotherapy to slow the tumor's growth. This treatment is followed by a partial nephrectomy in which we remove the affected part of the kidney, taking care to save as much of the kidney as possible.

Why choose us for treatment of hemihypertrophy?

Children's Colorado has medical specialists experienced in treating all types of tumors related to hemihypertrophy. From our Surgical Oncology Program that diagnoses, monitors and treats hemihypertrophy-related tumors, to our Genetics and Inherited Metabolic Diseases Program that helps to diagnose related genetic diseases, we work in close collaboration to care for every one of your child's needs. We also work closely with our Vascular Anomalies Center if the particular case of hemihypertrophy is related to a vascular malformation. Having a multidisciplinary team in one location helps us treat this complex condition while easing the burden on you and your child.

• The Beckwith Wiedemann Support Group provides information and support to families of children with Beckwith-Wiedemann syndrome and hemihypertrophy.
• Global Genes, Allies is Rare Diseases is a group of friends, family and supporters of patients who are affected by rare disease. Members of the group seek to connect, empower and inspire the rare disease community.