A Case of Leptomeningeal Carcinomatosis Manifesting With Vertigo in the Setting of Intracranial Hypertension.

Leptomeningeal carcinomatosis (LMC) is a rare condition where malignant cells infiltrate the leptomeninges of the central nervous system. We present a case of a 51-year-old male with stage IV adenocarcinoma of the lung who developed recurrent vertigo. The patient initially received a diagnosis of peripheral vertigo, but his symptoms worsened over time and were associated with headache, vomiting, and one episode of seizure. Upon readmission, based on his normal neuroimaging results, normal CSF examination with elevated opening pressure, and papilledema on fundoscopic examination, a diagnosis of pseudotumor cerebri was made. The result of CSF cytology revealed the presence of malignant cells confirming the presence of LMC. This case highlights the importance of considering LMC as a potential cause for unusual neurological symptoms in patients with advanced malignancy, particularly when other conditions like pseudotumor cerebri could obscure its presentation. It is crucial to rule out malignancy through CSF cytology in patients presenting with vertigo and/or other vestibulocochlear symptoms before making an alternative diagnosis that could present similarly.