What type of abnormal growth can invade the cornea?

The type of abnormal growth that can invade the cornea is a pterygium. A pterygium is a benign growth of the conjunctiva that extends onto the cornea. It often develops on the nasal side of the eye and can gradually invade the corneal surface. Pterygia are associated with prolonged exposure to UV light, dry eyes, and environmental factors, leading to significant visual disturbances if they grow large enough to affect vision directly.

In contrast, other options represent different structures or conditions. The caruncle is a small, fleshy outgrowth located at the inner corner of the eye and does not invade the cornea. Lipid cysts, which are generally noninvasive and occur in the conjunctival layer, do not typically impinge upon the cornea itself. Adnexal offal refers to tissues associated with the eye, such as eyelids or accessory structures, but it does not describe a growth that invades the cornea. Thus, the pterygium is characterized by its capacity to encroach upon the corneal surface, which makes it the correct answer in this context.