Classification of Lymphatic-system Malformations in Primary Lymphoedema based on MR Lymphangiography

ObjectivesThe study aims to investigate lymphatic-system malformations and proposes a classification of primary lymphoedema based on comprehensive imaging data of both lymph vessel- and lymph-node abnormalities.Materials and methodsA total of 378 patients with primary lymphoedema of the lower extremity were examined with magnetic resonance lymphangiography (MRL) using gadobenate dimeglumine as contrast agent. Lymph vessels and drainage lymph nodes were evaluated, leading to the proposal of the classification of primary lymphoedema and the relative proportions.ResultsA total of 63 (17%) patients exhibited defects of the inguinal lymph nodes with mild or moderate dilatation of afferent lymph vessels. A total of 123 (32%) patients exhibited lymphatic anomalies as lymphatic aplasia, hypoplasia or hyperplasia with no obvious defect of the drainage lymph nodes. The involvement of both lymph vessel- and lymph-node abnormalities in the affected limb was found in 192 (51%) patients. The primary lymphoedema was classified as three major types as: (1) lymph nodes affected only; (2) lymph vessel affected only with three subtypes and (3) both lymph vessel and lymph node affected with subgroups.ConclusionsA comprehensive classification of lymphatic-system malformation in primary lymphoedema is proposed, which clearly defines the location and pathologic characteristics of both lymphatics and lymph node and may lead to further study of the aetiology as well as rational treatment of the disease.