Postoperative polymyalgia rheumatica after lung cancer resection in the absence of immune checkpoint inhibitors: A case report and literature review

The present case report describes the development of polymyalgia rheumatica (PMR) in a 73-year-old male patient following lung cancer resection in the absence of prior exposure to immune checkpoint inhibitors (ICIs). Following a left upper lobectomy, the patient presented with a persistent fever and diffuse myalgia and arthralgia, which was unresponsive to antibiotic therapy. Subsequently, the patient was treated with non-steroidal anti-inflammatory therapy, which led to rapid clinical improvement and complete resolution of PMR-associated symptoms during the 6-month follow-up. Unlike the well-recognized ICI-associated PMR, the present case highlights a distinct postoperative presentation, suggesting that tumor-associated inflammation and surgical stress may act as independent triggers. Through a literature review, the present study further explores the potential mechanistic links between lung cancer and PMR, including the role of pro-inflammatory cytokines such as interleukin-6. These findings provide additional insight into PMR pathogenesis beyond immunotherapy-related mechanisms and may aid in the differential diagnosis of an unexplained fever and musculoskeletal symptoms in postoperative patients with cancer.