LYMPHATIC VESSELS IN HUMAN EYELIDS: AN IMMUNOHISTOLOGICAL STUDY IN DERMATOCHALASIS AND CHALAZION

Abstract

We investigated lymphatic morphologyand expression of endothelin (ET-1) axismolecules in human eyelids affected by aninflammatory state (chalazion) and an agerelateddegenerative condition (dermatochalasis).Lymphatics were immunohistologicallydetected by D2-40/LYVE-1 staining.Absorbing lymphatic vessels were localized inpapillary dermis and around skin appendageswith distinctive morphology. In chalazion,D2-40 reactive flattened lymphatic profileswere compressed by inflammatory infiltrate;in dermatochalasis, large fully openedlymphatics were observed, with a significantlywider total area (lymphatic lumina/200x field;p<0.05). The lymphatic density (number/200xfield) in the two groups was within the samerange. Lymphatic dilation is possiblydependent on reduction and fragmentationof the dermal elastic network as well as ofoxytalanic fibers in the papillary dermis ofdermatochalasis, as shown by Weigert’sreaction. Multifunctional peptide ET-1,involved in vasomotion, inflammation andconnective proliferation, was faintly anddiscontinuously localized on lymphatics, aswas its type A receptor. In contrast, theconsistent expression of type B receptorindicates that lymphatic endothelium is aphysiological target for ET-1, whose effectsare modulated by multiple pathophysiologicalconditions. Thus, vasoactive factors play a rolein the physiology of richly vascularized eyelids,and therefore, morphofunctional characterizationof lymphatic vessels may be useful insuggesting treatment options.