What happened, in summary

A 75-year-old man was being followed for pleural thickening that was ultimately diagnosed as IgG4-related disease. During that evaluation, doctors also found squamous cell carcinoma in the lower lobe of the left lung. The coexisting inflammatory disease made accurate lung-cancer staging difficult. Surgery was not feasible because his lung function remained poor, so he began carboplatin plus nab-paclitaxel in January 2017. After 5 cycles, the lung nodule shrank and remained controlled for about 2 years. By July 2019, the lung lesion and mediastinal nodes had clearly grown again. Testing showed PD-L1 expression of 65%, and nivolumab was started in November 2019. He was able to continue immunotherapy for 15 months without a major flare of the IgG4-related disease or serious immune toxicity. Nivolumab was eventually stopped because the cancer progressed. He died from progressive lung cancer 17 months later.