Pathology of eyelid tumors.

The eyelids are composed of four layers: skin and subcutaneous tissue including its adnexa, striated muscle, tarsus with the meibomian glands, and the palpebral conjunctiva. Benign and malignant tumors can arise from each of the eyelid layers. Most eyelid tumors are of cutaneous origin, mostly epidermal, which can be divided into epithelial and melanocytic tumors. Benign epithelial lesions, cystic lesions, and benign melanocytic lesions are very common. The most common malignant eyelid tumors are basal cell carcinoma in Caucasians and sebaceous gland carcinoma in Asians. Adnexal and stromal tumors are less frequent. The present review describes the more important eyelid tumors according to the following groups: Benign and malignant epithelial tumors, benign and malignant melanocytic tumors, benign and malignant adnexal tumors, stromal eyelid tumors, lymphoproliferative and metastatic tumors, other rare eyelid tumors, and inflammatory and infections lesions that simulate neoplasms.