They include a wide range of congenital (and acquired) anomalies in the development of the lymphatic system, which may feature lymphatic aplasia, hypoplasia, or hyperplasia. Dysplastic anomalies may affect lymphatic vessels and lymph nodes, either individually or in association, thus leading to complex pathological pictures that have recently been grouped into a nosological classification proposed by C. Papendiek, which comprises three different groups of dysplasias:
- LAD I lymphangiodysplasias;
- LAD II lymphadenodysplasias;
- LAAD lymphangioadenodysplasias.
The most important clinical manifestations of anomalies caused by dysplasia are: cystic hygroma, hydrops foetalis, lymphangioma and, more commonly, syndromes due to chylous and/or lymphatic reflux and peripheral lymphedema