Differential diagnosis of interstitial lung diseases (ILDs) during the COVID-19 pandemic is difficult, due to similarities in clinical and radiological presentation between COVID-19 and other ILDs on the one hand, and frequent false-negative swab results on the other. We describe a rare form of interstitial and organizing pneumonia resembling COVID-19, emphasizing some key aspects to focus on to get the right diagnosis and treat the patient properly. A 76-year-old man presented with short breath and dry cough in the midst of the COVID-19 outbreak. He showed bilateral crackles and interstitial-alveolar opacities on X-ray, corresponding on computed tomography (CT) to extensive consolidations with air bronchograms, surrounded by ground glass opacities (GGO). Although his throat-and-nasopharyngeal swab tested negative, the picture was overall compatible with COVID-19. On the other hand, he showed subacute, rather than hyperacute, clinical onset; few and stable parenchymal consolidations, rather than patchy and rapidly evolving GGO; pleural and pericardial thickening, pleural effusion, and lymph node enlargement, usually absent in COVID-19; and peripheral eosinophilia, rather than lymphopenia, suggestive of hypersensitivity. In the past year, he had been taking amiodarone for a history of ventricular ectopic beats. CT scans, in fact, highlighted hyperattenuation areas suggestive of amiodarone pulmonary accumulation and toxicity. Bronchoalveolar lavage fluid (BALF) investigation confirmed the absence of coronavirus genome in the lower respiratory tract; conversely, high numbers of foamy macrophages, eosinophils, and cytotoxic T lymphocytes with low CD4/CD8 T-cell ratio were detected, confirming the hypothesis of amiodarone-induced cryptogenic organizing pneumonia. Timely discontinuation of amiodarone and initiation of steroid therapy led to resolution of respiratory symptoms, systemic inflammation, and radiographic opacities. A comprehensive analysis of medical and pharmacological history, clinical onset, radiologic details, and peripheral and BALF cellularity, is required for a correct differential diagnosis and management of ILDs in the COVID-19 era.

中文翻译：

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胺碘酮诱发的类似 COVID-19 的机化性肺炎：病例报告


在 COVID-19 大流行期间，间质性肺疾病 (ILD) 的鉴别诊断很困难，一方面是因为 COVID-19 与其他 ILD 之间的临床和放射学表现相似，另一方面是由于拭子结果频繁出现假阴性。我们描述了一种类似于 COVID-19 的罕见间质性和机化性肺炎，强调了需要重点关注的一些关键方面，以便获得正确的诊断并正确治疗患者。一名 76 岁男子在 COVID-19 爆发期间出现呼吸短促和干咳的症状。他在 X 射线上显示双侧裂纹和间质肺泡混浊，与计算机断层扫描 (CT) 上对应的是空气支气管征的广泛实变，周围有毛玻璃混浊 (GGO)。尽管他的喉咙和鼻咽拭子检测结果呈阴性，但图像总体上与 COVID-19 相符。另一方面，他表现出亚急性而非超急性的临床发病。少量且稳定的实质整合，而不是零散且快速发展的 GGO；胸膜和心包增厚、胸腔积液和淋巴结肿大，这些在 COVID-19 中通常不存在；外周血嗜酸性粒细胞增多，而非淋巴细胞减少，提示过敏。去年，他因室性异位搏动病史一直在服用胺碘酮。事实上，CT 扫描突出显示了提示胺碘酮肺部蓄积和毒性的高衰减区域。支气管肺泡灌洗液（BALF）检查证实下呼吸道不存在冠状病毒基因组；相反，检测到大量泡沫状巨噬细胞、嗜酸性粒细胞和细胞毒性 T 淋巴细胞，且 CD4/CD8 T 细胞比率较低，证实了胺碘酮诱导的隐源性机化性肺炎的假设。 及时停用胺碘酮并开始类固醇治疗可缓解呼吸道症状、全身炎症和放射学混浊。在 COVID-19 时代，需要对医学和药理学史、临床发病、放射学细节以及外周血和 BALF 细胞结构进行全面分析，以正确鉴别诊断和管理 ILD。