Pulmonary pleomorphic carcinoma treated with PD‐1 inhibitor: Two case reports

Abstract Pulmonary polymorphic carcinoma (PPC) is a rare and poorly differentiated form of non‐small cell lung cancer (NSCLC), accounting for just approximately 0.1% to 0.4% of all NSCLC cases. Historically, the conventional treatments for PPC have been linked to a grim prognosis. However, with the advent of immune checkpoint inhibitors (ICIs), including PD‐1 inhibitors, for the management of NSCLC, our center has witnessed encouraging outcomes in two PPC patients who underwent PD‐1 inhibitor therapy. The first patient was a 70‐year‐old male who initially came to our attention after the discovery of a lung mass during a routine physical examination. A lung biopsy confirmed the diagnosis of PPC, and further complications included brain metastasis. Surgical intervention was conducted for the brain metastases, while PD‐1 inhibitor therapy was employed for the lung tumors. The second patient was a 60‐year‐old male who was admitted with a history of persistent coughing and hemoptysis, which led to the diagnosis of a left lung tumor. Subsequent postoperative pathology revealed pulmonary adenocarcinoma coexisting with PPC. However, 2 months later, distant metastases were detected during a follow‐up examination. The patient encountered difficulty in tolerating the adverse effects of chemotherapy, prompting the initiation of PD‐1 inhibitor treatment. Notably, both patients underwent one cycle of PD‐1 inhibitor therapy without encountering significant adverse reactions, and their responses proved to be promising during re‐examinations. These findings suggest that surgery combined with immunotherapy PD‐1 inhibitor therapy may represent an effective approach for the treatment of PPC