The most common conjunctival cancers are squamous carcinoma, malignant melanoma, and lymphoma.
Squamous carcinomas are either nodular or diffuse.
These tumors rarely metastasize but they can invade around the eye into the orbit and sinuses. A simple biopsy can determine whether a pigmented conjunctival tumor is a nevus, primary acquired melanosis, or conjunctival melanoma. Both squamous carcinomas and malignant conjunctival melanomas should be removed or destroyed. Lymphomas can also occur in the conjunctiva. These tumors look like salmon-colored patches on the eye and can be a sign of systemic lymphoma.