Background: Lymphoscintigraphy (LS) is the diagnostic test of choice differentiating lymphoedema from other causes of extremity swelling. The LS patterns in normal and congenital lymphoedema in the paediatric population are not well defined. The impact of LS on clinical decision making is also not well reported.

Aims: 1.define normal LS patterns in the pediatric population 2.describe types of abnormality (aplasia, hypoplasia, hyperplasia/ dilated system) 3.describe LS patterns in syndromic lymphatic vascular disease 4.correlate LS with clinical impact on patient management.

Methods: Retrospective review of all paediatric patients who had LS from July 1996–April 2008 was undertaken. Indications, sites of abnormality, LS patterns and clinical outcome were reviewed.

Results: 118 patients (3mths-21yrs, mean 6 yrs) underwent LS. Normal LS patterns and variations were identified in 57 pts (48%). Sixty-one scans (52%) were abnormal showing lymph node aplasia (11%), hypoplasia (17%), mixed-pattern (8%), hyperplasia/ dilated system (4%) and other patterns ie intestinal/ pulmonary lymphangiectasia and vascular lymphatic malformations(11%). Patients with no signs of lymphoedema may still have aplasia or hypoplasia on LS. Dermal back flow is not always seen in lymphoedema. Management impact related to diagnosis and potential for development of lymphoedema in other limbs, differentiation of lymphoedema in patients with other vascular anomalies, stratification for lymphoedema therapy or referral to the dysmorphology clinic.

Conclusion: LS is a valuable tool in the evaluation of lymphoedema in pediatric patients. Recognition of scan patterns in patients with suspected lymphoedema or lymphatic vascular diseases is essential as it plays a major role in the clinical management.