Ziya Zhao,1,* Hui Gan,2,* Bin-jie Fu,1 Wangjia Li,1 Fajin Lv,1 Zhigang Chu1 

1Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People’s Republic of China; 2Department of Radiology, The Second Affiliated Hospital of Army Medical University, Chongqing, 400016, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Zhigang Chu; Fajin Lv, Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, 1# Youyi Road, Yuanjiagang, Yuzhong District, Chongqing, 400016, People’s Republic of China, Tel +86 23 89012302, Fax +86 23 68811487, Email chuzg0815@163.com; fajinlv@163.com

Purpose: Compared to solid lung adenocarcinomas (LUADs), part-solid LUADs rarely exhibit lymph node metastasis (LNM) and generally have a favorable prognosis. This study aims to comprehensively investigate the clinical, pathological, and CT characteristics of part-solid LUADs with LNM.
Patients and Methods: This study collected 70 pathologically confirmed part-solid LUADs at two centers, including 35 cases with LNM and 35 matched cases without LNM based on size, CT pattern, and pathological subtype. Their clinical, pathological, and CT features were comprehensively analyzed and compared to identify the characteristics of part-solid LUADs associated with a high risk of LNM.
Results: Among the 3,457 IACs manifested as part-solid lesions, a total of 35 (1.01%) cases were found to be associated with LNMs. Clinically, patients with and without LNM were similar. Pathologically, lesions exhibiting predominant micropapillary/solid pattern (11.4% vs 0.0%), and containing micropapillary (48.6% vs 25.7%) or any high-grade histological pattern were all more common in part-solid LUADs with LNM than in those without (each P < 0.05). Radiologically, solid components located at the tumor margins or distributed in a scattered manner (odds ratio [OR] = 4.048, P = 0.038) and consolidation-to-tumor ratio (CTR) > 57.2% (area) (OR = 45.649, P = 0.041) were independent predictors of LNM, with an area under the curve of this model being 0.881, sensitivity of 97%, and specificity of 77.1% (P < 0.001).
Conclusion: LNM in part-solid LUADs is more prevalent in IACs with high-grade patterns, particularly the micropapillary pattern, with these lesions presenting as part-solid lesions that often have a larger CTR or distinct distribution of solid components.

Keywords: lymphatic metastasis, lung neoplasms, adenocarcinoma of lung, tomography, X-ray computed