

Definition
Lateralized overgrowth - asymmetry between left and right side of body
May affect
- cranium
- face
- trunk
- limbs
- +/- affect viscera
Types
Idiopathic - isolated hemihypertrophy / hemihyperplasia
Syndromic
- Beckwith- Weidmann syndrome
- Neurofibromatosis
- Klippel-Trenaunay-Weber syndrome - hemihypertrophy + vascular malformations
- Proteus syndrome - vascular + lymphatic malformations + lipomas
Issue
Incidence of tumour development in children
Idiopathic
Hoyme et al Am J Med Genetic 1998
- 168 idiopathic hemihypertrophy
- tumour incidence 6%
- Wilms tumor, hepatoblastoma, adrenal cell carcinoma, leiomyosarcoma small bowel in one case
Beckwith-Weidermann syndrome
Predisposition for embryonal tumors (Wilms)
- 3 - 5% in early childhood