Conjunctival/Corneal Tumors //
Tumors of the conjunctiva and cornea are usually considered together, because lesions from one area will frequently cross over and involve the other. With the exception of pterygia, most are relatively rare. These lesions can be divided into a number of categories:
The most common congenital tumors are corneal/conjunctival dermoids. These are lesions composed of displaced embryonic tissue (i.e., muscle fibers and hair where none normally develop). They are relatively smooth, white, rounded lesions that are most frequently found along the lower or outer edge of the cornea. They are present at birth and tend to enlarge gradually. They do not invade the ocular tissues and as such have no malignant potential. Treatment may range from simple observation to surgical excision.
Non-pigmented conjunctival tumors of the cornea/conjunctiva may be subdivided into those that are completely benign and those that have some malignant potential. Conjunctival cysts (either congenital or acquired) and viral papillomas with a frond-like vascular pattern fit into the former category. Pre-cancerous and cancerous lesions often develop at the junctional zone between the conjunctiva and cornea. This region is called the limbus. The malignant potential of these lesions can not be fully appreciated without a tissue biopsy. Fortunately, even when malignant, these tumors respond well to local therapy and rarely spread beyond the ocular and lid surfaces.
Non-pigmented conjunctival tumors composed of lymph gland cells (lymphocytes) may occasionally be seen. Similarly, metastatic lesions from tumors involving the lung, colon, breast, etc., may occasionally spread to the conjunctiva.
Nevi and freckles are pigmented conjunctival lesions with minimal malignant potential. Many of these are present at birth or develop prior to, or during puberty. Most pigmented lesions need to be careful documented by photographs or drawings since questions often arise as one gets older regarding when these lesions first presented and if they have undergone changes in size or appearance. Lesions that are noted for the first time after the late teens, or those showing unusual growth or change should be excised. Pre-cancerous lesions most frequently originate from these groups. Within this category of lesions, conjunctival malignant melanomas are the lesion of greatest concern since it can cause significant local destruction and is capable of spreading systemically to other parts of the body.