Immune-related aseptic meningitis diagnosed by Cube FLAIR on enhanced magnetic resonance imaging for a lung cancer patient administered atezolizumab: A case report.

Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), such as neurological toxicity. A 46-year-old man was diagnosed with squamous cell lung cancer. Lung cancer recurred 3 years after he experienced left segmental lung rejection. Therefore, he received atezolizumab as fourth-line chemotherapy. He experienced fever, headache, and decreased consciousness 10 days after the first dose of atezolizumab. Plain head computed tomography and cerebrospinal fluid examination showed no significant findings. Magnetic resonance imaging (MRI) with a Gadolinium (Gd)-enhanced Cube fluid-attenuated inversion recovery (FLAIR) sequence showed nodular abnormalities with contrast enhancement. Thus, aseptic meningitis caused by ICIs was suspected. His consciousness level gradually improved with glucocorticoid therapy. Moreover, most nodular abnormalities observed on cerebral MRI disappeared concurrently. Thus, Gd-enhanced Cube FLAIR sequence has the unique ability to reveal immune-related aseptic meningitis.