Table 1_Diffuse panbronchiolitis as a rare complication of thymectomy and radiation therapy in a patient with thymoma: a case report.docx

BackgroundDiffuse panbronchiolitis (DPB) is an uncommon respiratory disorder characterized by the presence of respiratory bronchiolitis and persistent inflammation in adjacent tissues, which can be effectively treated with early diagnosis and intervention. DPB is a rare complication associated with thymoma that remains poorly understood, especially when it occurs in conjunction with acquired cellular immune deficiency.
Case presentationWe present a case of DPB in a patient with thymoma following thymectomy and radiation therapy. A 47-year-old Chinese man underwent thymectomy due to the presence of a mediastinal mass, and pathological examination confirmed a type B2 thymoma. He also underwent 25 sessions of radiation therapy. The patient’s respiratory symptoms, including cough, expectoration, and shortness of breath, worsened significantly after radiation treatment. Immune dysfunction, marked by CD4+ T cell immunodeficiency with normal immunoglobulin levels, was observed. Chest computed tomography revealed diffuse nodules with tree-in-bud signs and new consolidation within the irradiated area, leading to a diagnosis of combined DPB and radiation pneumonitis. The patient’s symptoms and lung imaging findings significantly improved after the initiation of low-dose oral azithromycin for DPB and low-dose glucocorticoid therapy for radiation pneumonitis.
ConclusionsClinicians should consider DPB in patients with thymoma and cellular immunodeficiency. Both thymectomy and radiation therapy can contribute to the development of DPB. Early treatment with macrolides can improve patient prognosis.

背景：弥漫性泛细支气管炎（Diffuse Panbronchiolitis，DPB）是一种少见的呼吸系统疾病，以呼吸性细支气管炎及邻近组织持续性炎症为特征，早期诊断与干预可实现有效治疗。DPB是与胸腺瘤（thymoma）相关的罕见并发症，目前对其认知仍较为不足，尤其当它与获得性细胞免疫缺陷同时出现时。
病例报告：我们报告1例胸腺瘤患者在胸腺切除术后接受放射治疗后并发DPB的病例。该患者为47岁中国男性，因纵隔肿物接受胸腺切除术，病理检查证实为B2型胸腺瘤（type B2 thymoma），随后完成25次放射治疗。患者在放疗后出现咳嗽、咳痰、气短等呼吸道症状显著加重。检查发现其存在免疫功能异常，表现为CD4+ T细胞（CD4+ T cell）免疫缺陷但免疫球蛋白水平正常。胸部计算机断层扫描（computed tomography，CT）显示照射野内出现弥漫性结节伴树芽征（tree-in-bud signs）及新发实变（consolidation），据此确诊为DPB合并放射性肺炎。患者接受针对DPB的口服小剂量阿奇霉素（azithromycin）及针对放射性肺炎的小剂量糖皮质激素（glucocorticoid）治疗后，症状及肺部影像学表现均得到显著改善。
结论：临床医师对于合并细胞免疫缺陷的胸腺瘤患者，应将DPB纳入鉴别诊断范畴。胸腺切除术与放射治疗均可能诱发DPB的发生。早期使用大环内酯类（macrolides）药物治疗可改善患者预后。