Stage IV lung cancer presenting with a paraneoplastic neurologic syndrome and mixed tumor features

What happened, in summary

A 45-year-old man in Tanzania developed loss of taste in May 2023, followed over several weeks by left-sided numbness, slurred speech, involuntary movements, insomnia, and an unsteady gait. Brain imaging showed multiple small areas of bleeding, but early scans did not identify a clear primary cancer. With infectious and autoimmune testing unrevealing, he was treated with steroids for a suspected cancer-related neurologic syndrome, and his condition stabilized temporarily.

Later imaging found an active lesion in the right lower lung and abnormalities in the spine. A biopsy from the T10 vertebra showed metastatic cancer consistent with a lung primary. The cancer had spread to the spine, making it Stage IV. PD-L1 was 0%.

He then received 4 cycles of carboplatin plus pemetrexed. His neurologic symptoms improved temporarily during treatment. Follow-up imaging still showed a right lower-lung mass, while brain imaging showed more small areas of bleeding. A later bronchoscopy found a tumor with mixed glandular and squamous features, suggesting that the lung cancer had developed more than one tumor pattern.

His condition then worsened rapidly, with severe confusion, difficulty speaking, generalized weakness, and breathing problems. He died before the later biopsy results could be discussed with his treating team.