%0 Journal Article %T Vitreous Diagnosis in Neoplastic Diseases %A M¨®nica Asencio-Duran %A Jos¨¦ Luis Vallejo-Garcia %A Natalia Pastora-Salvador %A Agust¨ªn Fonseca-Sandomingo %A Mario R. Romano %J Mediators of Inflammation %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/930704 %X Vitreous body is an intraocular structure, origin of diverse pathologies, but is also the place where cells and inflammatory mediators are released coming from several pathologic processes. These inflammatory reactions can happen in any other ocular location like choroid, retina, optic nerve, or ciliary body and vitreous humor constitutes a stagnant reservoir for these resulting substances and debris. Through the recent techniques of vitreous collecting, handling, and analysis, increasingly more sophisticated and with fewer complications, cellularity and molecules in the vitreous of challenging pathologies for the ophthalmologist can now be studied. The most usefulness for vitreous diagnosis would be the masquerade syndromes, and the best exponent in this group is the primary vitreoretinal lymphoma (PVRL), in which cytology and an IL-10/IL-6 ratio more than 1 is fundamental for the diagnosis. 1. Introduction Vitreous body is the clear gel that fills the vitreous chamber or posterior chamber (PC) of the eyeball, the space between the lens and the eyewall, whose inner layer is the neurosensorial tissue that receives and transmits the image to the central nervous system called the retina. Its functions are to give volume to the eye, to support the retina attached, and to maintain its transparency to allow light beams to reach onto the retina. Unlike the fluid in the anterior segment of the eye (aqueous humour), which is continuously replaced, vitreous humor is stagnant, and its composition remains quite constant throughout life. The vitreous gel is avascular, composed mainly of water (98-99%), and 0.9% of inorganic salts (sodium, potassium, and chloride). The remaining 0.1% is divided between protein, polysaccharide components, and ascorbic acid. Most of the protein is forming fibrils composed of a small collagen type V/XI core wrapped in a thick layer of collagen type II (75% of the fibril by mass) [1, 2]. It also contains very few cells, mostly phagocytes, whose function is to remove undesired cellular debris from the visual field, as well as hyalocytes of the surface of vitreous, which act as macrophages [3, 4]. The vitreous is feebly antigenic and is characterized by the absence of gamma-globulins and immunocompetent cells [5]. Because it only exhibits phagocytosis, this represents an incomplete and primitive immunological system, reacting like an embryonic tissue. The immune privilege, also, a physiologic mechanism characteristic of the internal compartments of the eye, is designed to provide protection against pathogens, protecting the delicate %U http://www.hindawi.com/journals/mi/2012/930704/