Cystic and Non-Cystic Lymphatic Malformations

Abstract

Lymphatic malformation (LM) results from an error in the embryonic development caused by genetic mutation in the lymphatic system at various body sites. Sprouting lymphatics are not linked with the main lymphatics. Lack of their contacts with the lumen of collecting vessels results either in the formation of cystic lesions filled up with lymph-like fluid or local interstitial fluid accumulation creating foci of circumscribed edema. The cystic lesions are found mainly in head, neck, thorax, and abdominal cavity, whereas, the regions with lack of interstitial fluid outflow appear mainly in the soft tissues of lower parts of the body. The cystic malformations are classified as microcystic and macrocystic or large cysts (Fig. 9.1 a, b, c). Upon puncture, lymph-like fluid can be obtained. There is another group of malformation characterized by non-cystic interstitial accumulation of fluid classically called Milroy’s disease. There are no walls separating fluid foci from the adjacent tissue (Fig. 9.1 c, d). Upon puncture, only some few drops of tissue fluid can be harvested. The actual problem in lymphology is whether to include Milroy disease to the malformation group or leave it as has been until now as the so-called “primary lymphedema” This is not only an academic problem, it has practical aspects. Whereas, cystic lesions have to be obliterated or/and be surgically removed, the tissue accumulation of edema fluid should be drained to the sites where it can be absorbed. It can be done either by external compression or formation of flow pathways using surgical methods. Diagnostic differentiation between the two conditions becomes necessary to establish proper therapeutic recommendations.