Okano Tomohito, Fujimoto Hajime, Ito Toshiyuki, Tomaru Atsushi, Saiki Haruko, Tsuruga Tatsuki, Yasuma Taro, D'Alessandro-Gabazza Corina N, Gabazza Esteban C, Kobayashi Tetsu
Department of Pulmonary and Critical Care Medicine, Faculty and Graduate School of Medicine, Mie University, Tsu, Mie, Japan.
Department of Immunology, Faculty and Graduate School of Medicine, Mie University, Tsu, Mie, Japan.
Am J Case Rep. 2025 Jan 8;26:e945022. doi: 10.12659/AJCR.945022.
BACKGROUND Pembrolizumab, a programmed cell-death protein-1 (PD-1)-targeting antibody, extends survival in cancer patients but may cause lung injury as a side effect. This immunotherapy enhances the immune system's ability to recognize and eliminate cancer cells. However, its immunomodulatory action can sometimes lead to immune-related adverse events, including lung injury. CASE REPORT A 40-year-old female patient, previously managed for malignant melanoma of the left gluteal region with surgery and immune checkpoint inhibitors, was transitioned to pembrolizumab for ongoing cancer treatment. Subsequently, she was referred to our department for further evaluation due to findings on chest imaging revealing multiple nodules in the bilateral lung fields. The patient exhibited neither cough, fever, nor breathlessness. Bronchoscopic examination yielded no abnormalities. Cytological assessments were negative, as were cultures for bacteria, fungi, and acid-fast bacilli. Bronchoalveolar lavage and endobronchial ultrasound-guided transbronchial needle aspiration biopsy of the right lower lobe bronchus B9a were conducted. Pathological analysis identified a combination of acute inflammatory and chronic fibrotic lesions, primarily histiocytic, leading to a diagnosis of pembrolizumab-induced lung injury. Steroid pulse therapy followed by tapering resulted in improvement of the pulmonary shadows. The patient is currently under observation without requiring steroid therapy. CONCLUSIONS This case underscores the importance of vigilance for potential pembrolizumab-induced lung injury in patients undergoing immunotherapy for cancer treatment. Prompt recognition and appropriate management are essential for optimizing patient outcomes. Additionally, this case highlights the challenge of diagnosing lung lesions based solely on imaging, necessitating bronchoscopy with tissue sampling as a critical diagnostic tool.
帕博利珠单抗是一种靶向程序性细胞死亡蛋白1（PD-1）的抗体，可延长癌症患者的生存期，但可能会引起肺部损伤这一副作用。这种免疫疗法可增强免疫系统识别和清除癌细胞的能力。然而，其免疫调节作用有时会导致包括肺部损伤在内的免疫相关不良事件。病例报告：一名40岁女性患者，此前因左臀恶性黑色素瘤接受手术及免疫检查点抑制剂治疗，现转用帕博利珠单抗进行持续的癌症治疗。随后，因其胸部影像学检查发现双侧肺野有多个结节，被转诊至我科作进一步评估。该患者既无咳嗽、发热，也无呼吸急促症状。支气管镜检查未发现异常。细胞学评估为阴性，细菌、真菌和抗酸杆菌培养结果也均为阴性。对右下叶支气管B9a进行了支气管肺泡灌洗及支气管内超声引导下经支气管针吸活检。病理分析发现主要为组织细胞性的急性炎症和慢性纤维化病变并存，从而诊断为帕博利珠单抗所致的肺部损伤。采用类固醇冲击疗法后逐渐减量，肺部阴影有所改善。该患者目前正在接受观察，无需类固醇治疗。结论：本病例强调了在接受癌症免疫治疗的患者中，警惕帕博利珠单抗所致肺部损伤的重要性。及时识别和恰当处理对于优化患者预后至关重要。此外，本病例突出了仅基于影像学诊断肺部病变的挑战，这使得支气管镜检查及组织取样成为关键的诊断工具。
