A tumor is an abnormal growth of any tissue or structure; it can be either benign or malignant. A tumor can affect any part of the eye, such as the eye socket, eyeball, eye muscles, optic nerve, fat, and tissues.

Sebaceous cell carcinoma is a type of tumor that originates in the eyelid glands of elderly individuals. It is relatively rare but still accounts for 1% to 5% of malignant eyelid tumors. These highly malignant tumors may recur, invade the eye socket, or spread to the lymph nodes. The tumor may look like a chalazion or stye, making it difficult to diagnose.

Immediate surgical intervention is usually necessary for this type of tumor. In some cases, radiation therapy may be an alternative or may be used in conjunction with surgery.

(c) 2007 The American Academy of Ophthalmology