Hemihypertrophy

Hemihypertrophy is a difficult diagnosis due to its rarity and the variety of associated conditions.  Basically, the diagnosis means that one extremity (or one side of the body) is enlarged compared to the other side.  As little as a 5% difference can be diagnostic but usually families seek care when the difference is more notable.  It can be dramatic.  As a hand and upper extremity surgeon, I typically see kids with one arm or one part of the hand which is larger than the other.  There is some information on the web which is useful including this website: http://hemisupport.com  The most commonly associated conditions are listed below (and there are others as well); not all patients will have a syndrome but we do assess for the following conditions.  I have only briefly summarized these conditions with links for more information.

Beckwith- Wiedemman syndrome is one possible diagnosis and its diagnosis is important to make because of possible associated tumors.  http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002168/

Proteus syndrome is an overgrowth condition affecting skin, bones, soft tissues, and other organs.  It may be asymmetrical.  This condition is exceedingly rare (1 in 1,000,000) and is related to a genetic abnormality (not inherited).  http://ghr.nlm.nih.gov/condition/proteus-syndrome

Klippel- Trenaunay Weber Syndrome.  KTW is characterized by port wine stains on the skin, extra bone and soft tissue growth, and varicose veins.  Classically associated with vascular malformations.   http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001205/

Neurofibromatosis is a condition with numerous nerve tumors which may grow rapidly.  Type 1 is more common and is associated with cafe au lait spots on the skin.  http://www.ninds.nih.gov/disorders/neurofibromatosis/neurofibromatosis.htm

 The orthopaedic surgeon or pediatrician often makes the diagnosis of hemihypertrophy but a geneticist is usually involved for full evaluation of the possible associations.  My role in hemihypertrophy is to provide information, refer families to geneticists and other providers, help make the appropriate diagnosis, and arrange referral or testing to rule out the rarely associated tumors (such as Wilms tumor).  Surgery for hemihypertrophy can sometimes be helpful to control growth (by limiting the growth plates) or to debulk enlarged areas.  Sometimes amputations are the best course of action.  Surgery is a difficult decision as our options are not ideal and the effectiveness of surgery is also limited.

One example of hemihypertrophy