We present a 62-year-old woman who, after a catarrhal episode, underwent a chest xray and a chest CT, identifying a pleural-based mass in the left lower lobe. This lesion presented a mixed pattern with solid and peripheral ground-glass attenuation, and an air-bronchogram sign. Despite de suspicion of bronchopneumonia, a lung neoplasm like a predominantly lepidic adenocarcinoma could not be ruled. A 18 F-FDG PET/CT showed a focal radiotracer uptake with SUVmax of 5.34 in the pulmonary lesion, supporting the neoplastic etiology. Consequently, a lower lobectomy was performed and histological examination concluded that the final diagnosis was a B lymphoid hyperplasia-type Castleman disease. Castleman’s disease is an uncommon disorder that can be easily misdiagnosed as lymphoma, neoplasm or infection. Unicentric Castleman’s disease (UCD) usually presents a hyaline-vascular histological subtype and is usually asymptomatic. Extranodal involvement is very rare. Only a few cases of solid organ involvement such us spleen or parotid gland have been described. UCD originating in the lung is extremely rare and should be considered in the differential diagnosis of a primary pulmonary malignant tumor.

中文翻译：

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18F-FDG PET / CT用于肺B淋巴样增生型Castleman病。

我们介绍了一名62岁的女性，该女性在发生卡他性发作后接受了胸部X线检查和胸部CT检查，发现左下叶存在基于胸膜的肿物。该病灶表现为混合型，实心和周围玻璃样衰减，并有气管支气管征。尽管怀疑支气管肺炎，仍不能排除肺肿瘤，如主要为鳞状上皮性腺癌。18 F-FDG PET / CT在肺部病变中显示出局灶性放射性示踪剂摄取，SUVmax为5.34，支持了肿瘤的病因学。因此，进行了下叶切除术并进行了组织学检查，结论是最终诊断为B淋巴样增生型Castleman病。Castleman病是一种罕见疾病，很容易被误诊为淋巴瘤，肿瘤或感染。单中心Castleman病（UCD）通常表现为透明血管组织学亚型，通常无症状。结外累及非常罕见。仅描述了少数几个实体器官受累的情况，例如我们的脾脏或腮腺。起源于肺的UCD极为罕见，应在鉴别诊断原发性肺恶性肿瘤时予以考虑。