Paraneoplastic Syndromes in the Orbit and Ocular Adnexa: A Comprehensive Review.

Paraneoplastic syndromes are a group of nonmalignant disorders caused by immunologic or nonimmunologic reactions in response to an underlying cancer. In the orbit and ocular adnexa, paraneoplastic syndromes can affect every structure. Early recognition of paraneoplastic syndromes can expedite diagnosis and improve outcomes for patients as they are often the first sign of potentially life-threatening malignancy. The purpose of this review is to characterize the paraneoplastic syndromes as they manifest in the periorbita and orbit.