Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, The Republic of Korea.
Department of Hospital Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, The Republic of Korea.
Thorac Cancer. 2020 Dec;11(12):3463-3472. doi: 10.1111/1759-7714.13674. Epub 2020 Oct 5.
Invasive mucinous adenocarcinoma (IMA) of the lung is a rare and distinct subtype of adenocarcinoma that can appear as airspace opacities on computed tomography (CT). In daily practice, we have occasionally encountered spontaneous regression of airspace opacities (SRAs) without treatment on serial CTs in patients with IMAs, which has not previously been described in the literature. Here, we describe serial CT findings with emphasis on SRAs in relation to clinicopathological features and treatment outcomes in patients with IMAs.
A total of 46 patients with pathologically-confirmed IMAs of the lung from January 2013 to June 2018 were included. Serial CT scans were reviewed and the patients were classified into SRA and no-SRA groups according to the presence of SRA. Radiological features, clinicopathological characteristics, and treatment outcomes were compared between the SRA and no-SRA groups.
A total of 32 patients were included in the no-SRA group and 14 patients in the SRA group. IMAs in the SRA group were mostly pneumonic (P < 0.001), larger (P < 0.001), multifocal (P = 0.001), and showed higher stage (P < 0.001) on initial CT. Of seven patients who died during follow-up, six were from the SRA group (P < 0.001). Mean overall survival for all IMAs was 86.6 months (range, 0-110 months), and the SRA group showed significantly worse overall survival (P < 0.001).
IMAs of the lung showing SRAs on serial CTs are larger and multifocal, and tend to be pneumonic in type on initial CT. Patients present at a higher stage of disease, with higher mortality rate and reduced overall survival.
SIGNIFICANT FINDINGS OF THE STUDY: Invasive mucinous adenocarcinomas (IMAs) of the lung can show spontaneous regression of airspace opacities (SRAs) on serial CTs, without being correlated to the administration of anticancer drugs. IMAs that showed SRAs demonstrated reduced overall survival in patients.
When airspace opacities show regression on CT, IMA should still be included in the differential diagnosis. A more careful application of RECIST 1.1 is needed in the assessment of tumor response of IMAs.
肺浸润性黏液腺癌（IMA）是一种罕见且独特的腺癌亚型，在 CT 上可表现为气腔实变。在日常实践中，我们偶尔会在未经治疗的情况下在连续 CT 上遇到 IMA 患者的气腔实变（SRA）自发消退，这在文献中尚未有描述。在这里，我们描述了与临床病理特征和治疗结果相关的连续 CT 发现，并重点介绍了 IMA 患者的 SRA。
共纳入 2013 年 1 月至 2018 年 6 月期间经病理证实的 46 例肺 IMA 患者。回顾性分析连续 CT 扫描，根据 SRA 的存在将患者分为 SRA 和非 SRA 组。比较 SRA 和非 SRA 组之间的影像学特征、临床病理特征和治疗结果。
共有 32 例患者纳入非 SRA 组，14 例患者纳入 SRA 组。SRA 组的 IMA 大多为肺炎型（P < 0.001）、更大（P < 0.001）、多灶性（P = 0.001）和更高的分期（P < 0.001）。在随访期间死亡的 7 例患者中，有 6 例来自 SRA 组（P < 0.001）。所有 IMA 的总生存时间为 86.6 个月（范围 0-110 个月），SRA 组的总生存时间明显更差（P < 0.001）。
肺 IMA 在连续 CT 上出现 SRA 时更大且多灶性，并且在初始 CT 上倾向于肺炎型。患者处于更高的疾病阶段，死亡率更高，总生存率降低。
本研究的重要发现：肺浸润性黏液腺癌（IMA）可在连续 CT 上出现气腔实变（SRA）自发消退，与抗癌药物的应用无关。出现 SRA 的 IMA 患者的总生存率降低。
当 CT 上的气腔实变出现消退时，仍应将 IMA 纳入鉴别诊断。在评估 IMA 的肿瘤反应时，需要更仔细地应用 RECIST 1.1。
