=Asymmetric overgrowth of one limb, or one side of the body, or just one side of the face.

Can be associated asymmetric overgrowth of internal organs.

Can be an isolated finding (of unknown cause) or associated with syndromes such as Beckwith-Wiedmann, Klippel-Trenaunay-Weber, or McCune-Albright syndromes.

Essentially a cosmetic problem. But increased risk of tumours, including Wilm’s tumour, adrenal cell carcinoma, hepatoblastoma and small bowel sarcoma.

Risk of tumour development in isolated hemihyperplasia is about 1 in 20 or approximately 5%. Given that oldest reported case was 6yrs and shortest interval between tumour presentation and ultrasound was 5 months, suggested hat till age of 6 years these children should have abdominal ultrasound scans at three monthly intervals.