What is hemihyperplasia

Hemihyperplasia, also called hemihypertrophy, refers to overgrowth of one side of the body in comparison with the other. The overgrowth may be limited to a portion of the body, such as the legs, or it may involve several different areas of the body, including the arms, face (causing asymmetry of the nose, eyes or cheeks), tongue, jaw, teeth and ears. All tissue types can be affected, including the bones, skin, muscle, fat and nerves that are connected to the area of overgrowth.

Hemihyperplasia can occur by itself (isolated), or it can be one of several characteristics of Beckwith-Wiedemann syndrome or another genetic syndrome. It can be diagnosed at birth or appear later in childhood, and can follow an irregular growth pattern. At times new growth may be excessive, while at other times it may be modest.


Children with hemihyperplasia may not show any symptoms other than a subtle difference between the two sides of the face. As overgrowth progresses, a greater difference may be seen and the overgrowth may lead to difficulty with eating, chewing seeing and breathing. Appearance-related concerns may arise as the disease progresses.


Hemihyperplasia is diagnosed with clinical examination and supplemented with radiologic studies such as a CT scan or MRI.


Treatment of hemihyperplasia addresses both functional and appearance-related purposes. Procedures performed include suction-assisted lipectomy, excision of excessive skin and subcutaneous tissue, and contouring or reducing facial bones.

The goal of surgery is to preserve as much nerve and muscle function as possible. Surgery can occur on an outpatient basis, or if it is more extensive it will require hospitalization for a one to two day period.

Incisions can vary around the face depending on the area that is hyperplastic but, in general, are hidden in creases, folds, or intraorally. A moderate amount of soft tissue swelling can occur following surgery and eating may be compromised short term following discharge. Swelling will improve over time and any numbness or the like as a consequence of the surgery will generally improve.

Why choose us

CHOP has a long history of treating children with hemihyperplasia. Experts specializing in oncology, plastic, reconstructive and oral surgery and genetics are familiar with the many presentations of this condition and related syndromes, and will work with you to develop an individualized treatment plan for your child’s unique condition.

Reviewed by: Scott Bartlett, MD
Date: March 2014

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