Contributor: Gordon K. Klintworth
Many different types of cysts with different derivations occur in the eye and its adnexa. The lining and contents of the various cysts vary considerably and are characteristic for each type of cyst. Cysts occur in the orbit [cyst - orbit], cornea [cyst - cornea], anterior chamber [cyst - anterior chamber], iris [cyst - iris], ciliary body [cyst - ciliary body], retina [cyst - retina], subretinal space and optic nerve [cyst - optic nerve]. Some are implantation cysts [cyst - implantation]; others are related to tumors (medulloblastoma), parasites (cysticercosis, hydatid disease) or developmental anomalies (microphthalmos with cyst, mucocele, dermoid cyst, choristomatous cyst). Cysts of the eyelids and periocular skin include epidermal inclusion cysts [cyst - inclusion], milia, eccrine hidrocystoma and apocrine hidrocystoma and dermoid cyst. In multiple myeloma cysts are sometimes found in the ciliary body between the pigmented and non-pigmented epithelia. They appear white after formalin fixation due to the precipitation of plasma proteins within them. Epithelial inclusion cysts may develop spontaneously in the anterior chamber or they follow trauma or surgery. Cysts also occur in many parts of the body including the kidney [cyst - kidney], pancreas [cyst - pancreas], ovary [cyst - ovary], liver [cyst - liver], bone [cyst - bone], and epididymis [cyst - epididymis].