■肺结节是胸部影像学检查的常见发现,差异包括多个良性实体,但恶性肿瘤通常也是一个问题。计算机断层扫描(CT)和氟脱氧葡萄糖(FDG)-正电子发射断层扫描(PET)扫描改善了肺结节的表征。然而,许多结核仍不确定,需要定期监测。在这里,我们报告了两例结节性肺淀粉样变性病例,这是FDG代谢扩大肺结节的罕见病因。
■案例1:有哮喘病史的75岁女性,肺气肿,支气管扩张,有48包年吸烟史,发现右下叶有亚厘米磨玻璃肺结节(RLL)。随访成像显示,在PET扫描中,与轻度FDG摄取相关的RLL大泡的固体成分增加。CT引导活检显示淀粉样蛋白沉积。案例2:77岁男性有间质性肺病史,石棉暴露,以前的烟草使用,发现胺碘酮治疗的心房颤动有1.6cm的RLL结节。在PET扫描中,随访成像发现与中度FDG摄取相关的间隔增加至2.0cm。经胸活检发现淀粉样蛋白沉积。
■结节性肺淀粉样变性是一种罕见形式的淀粉样变性,可能表现为FDG代谢增加的肺结节,引起对恶性肿瘤的关注。CT引导活检是建立诊断的安全方法。最近的研究表明,结节性肺淀粉样变性与边缘区淋巴瘤之间存在关联,这需要对淋巴增生性疾病的演变进行纵向随访。
UNASSIGNED: Pulmonary nodules are a frequent finding on chest imaging studies, with differential including multiple benign entities, but malignancy is often also a concern. Computed Tomography (CT) and Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET) scans have improved the characterization of pulmonary nodules. However, many nodules remain indeterminate and require periodic monitoring. Here we report two nodular pulmonary amyloidosis cases as a rare etiology of enlarging pulmonary nodules with FDG avidity.
UNASSIGNED: Case 1: 75-year-old woman with a history of asthma, emphysema, bronchiectasis, and a 48 pack-year smoking history was found to have subcentimeter groundglass pulmonary nodules in the right lower lobe (RLL). Follow-up imaging demonstrated an increased solid component of a RLL bulla associated with mild FDG uptake on PET scan. A CT-guided biopsy revealed amyloid deposition. Case 2: 77-year-old man with a history of interstitial lung disease, asbestos exposure, prior tobacco use, and atrial fibrillation treated with amiodarone was found to have a 1.6cm RLL nodule. Follow-up imaging identified an interval increase to 2.0cm associated with moderate FDG uptake on PET scan. Transthoracic biopsy identified amyloid deposition.
UNASSIGNED: Nodular pulmonary amyloidosis is a rare form of amyloidosis which may present as an enlarging pulmonary nodule with FDG avidity, raising concern for malignancy. A CT-guided biopsy is a safe way to establish a diagnosis. Recent studies have demonstrated an association between nodular pulmonary amyloidosis and marginal zone lymphomas, which warrants longitudinal follow-up for evolution to lymphoproliferative disorder.