A Case of MRI-Negative Leptomeningeal Disease From Non-small Cell Lung Cancer

Leptomeningeal disease (LMD) is a rare complication of advanced non-small cell lung cancer (NSCLC), associated with a poor prognosis. We report the case of a 55-year-old man, who presented with a metastatic NSCLC with limited brain and abdominal metastases. He was treated with both chemoimmunotherapy and stereotactic radiotherapy (SRT) to the brain. Despite treatment, the patient experienced progressive neurological symptoms not in keeping with the extent of disease seen on imaging of the brain. Due to this incongruence between symptoms and radiologic findings, he underwent a lumbar puncture, which had positive cytology for LMD. He had a rapid progression of symptoms and died six days after the discovery of LMD. We review the available literature regarding the prevalence of MRI-negative LMD from a solid primary malignancy.