A Tetrad Catastrophe: Paraneoplastic Syndrome With Abducens Palsy, Intracranial Hypertension, and Optic Neuropathy in Primary Lung Cancer.

We report a unique case of paraneoplastic syndrome (PS) associated with primary lung cancer. A 57-year-old woman experienced headaches and bilateral visual loss one month after the onset of isolated right abducens palsy. Examination revealed bilateral poor visual acuity (VA), papilledema, and persistent right abducens palsy. Neuroimaging was normal. Lumbar puncture revealed high cerebrospinal fluid (CSF) opening pressure and protein levels. She was started on acetazolamide and pulse methylprednisolone followed by oral corticosteroids. Her abducens nerve palsy resolved, but her VA deteriorated. Anti-Hu and anti-CV2 were positive. A positron emission tomography (PET) scan revealed primary lung cancer, and she died six months after her initial presentation. This case demonstrated that PS poses a diagnostic challenge and may be associated with poor prognosis.