Opsoclonus as a suspected paraneoplastic syndrome of endometrial cancer.

Paraneoplastic opsoclonus is well described in neuroblastoma. In the adult oncologic population, opsoclonus is seen usually within the context of opsoclonus-myoclonus ataxia and is associated most strongly with small-cell lung cancer. Patients with paraneoplastic opsoclonus are often seronegative. Patients with gynecologic malignancies are known to be predisposed to paraneoplastic syndromes; however, we describe the first case of paraneoplastic opsoclonus in association with endometrial cancer.