肺弥漫性淋巴组织增生（DLH）是一种非肿瘤性淋巴增殖性疾病（LPD），非常罕见，目前尚未报告肺DLH的PET / CT表现。我们观察到一名51岁无症状男性右下叶存在缓慢扩张的不规则浸润阴影，并出现了18F-FDG的积聚（SUVmax为3.64）。患者进行了经视频辅助的胸腔镜活检，以怀疑恶性病变。组织学检查显示没有肿瘤细胞存在，病变与DLH一致。六个月后，患者患上了类风湿性关节炎。即使没有已知的免疫异常，应考虑DLH在PET阳性不规则阴影的鉴别诊断中。版权所有©2023 Wolters Kluwer Health，Inc.保留所有权利。

Pulmonary diffuse lymphoid hyperplasia (DLH), a nonneoplastic lymphoproliferative disorder (LPD), is extremely rare, and no PET/CT findings have been reported for pulmonary DLH. We observed slowly expanding irregular opacities with 18F-FDG accumulation (SUVmax, 3.64) in the right lower lobe of a 51-year-old asymptomatic man. The patient underwent video-assisted thoracoscopic biopsy on suspicion of malignant lesions. Histologically, no neoplastic cells were present, and the lesion was consistent with DLH. Six months later, the patient developed rheumatoid arthritis. DLH should be considered in the differentiation of PET-positive irregular opacities, even in the absence of known immune abnormalities.Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.