Manifestations and natural history of idiopathic hemihypertrophy: a review of eleven cases.

Idiopathic hemihypertrophy is a specific entity which is distinct from the numerous other causes of limb overgrowth. In our investigation of eleven new cases in South Africa and Australia, no genetic or other aetiological factors could be recognised. There were no differences in bone age between the normal and hypertrophied limbs and the pattern of growth through life showed that relative body proportions remained the same. Idiopathic hemihypertrophy is associated with mild mental retardation, genito-urinary anomalies and an oncogenic potential. Regular clinical surveillance for abdominal tumours is recommended.