Objective:To investigate the clinicopathological features and genetic characteristics of congenital cystic adenomatoid malformation (CCAM) of lung and CCAM associated lung cancer in adults.Methods:A total of 13 cases of CCAM of lung in adults, diagnosed from June 2015 to May 2023, were collected from the Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, China. Their histopathological features were correlated with probable development into lung cancer. Next-generation sequencing was performed on the benign and malignant areas of all cases.Results:The pathological classification of all cases were of CCAM of lung type 1. There were 4 male and 9 female cases, age ranged from 18 to 65 years, with a mean age of 41 years. Six cases were accompanied by lung cancer, all of them were mucinous adenocarcinoma. Next-generation sequencing showed no gene mutation in 2 of the 13 cases; KRAS mutations in exon 2 were detected in 7 cases, in which there were 6 cases complicated with lung mucinous adenocarcinoma and no matter in the malignant or benign regions, the same case exhibited the same mutation sites in KRAS gene.Conclusions:CCAM of the lung is a congenital disease, and in adults, type 1 is most commonly found in the pathological classification, and it is often accompanied by cancer. Gene mutations are frequently detected in CCAM of the lung, KRAS being the most recurrent mutation which may play an important role in the carcinogenesis.

Background:Fusobacterium nucleatum (Fn)is a common oral pathogen. Studies have shown that Fn is closely related to the occurrence and development of colorectal cancer,especially the inflammation-related colorectal cancer. Aims:To investigate the mechanism of Fn in forming an inflammatory microenvironment in colon cancer cells. Methods:An inflammation model of Caco-2 cells infected by Fn was constructed,and miRNA sequencing was performed. miR-181b mimics or inhibitor was transfected into Fn infected Caco-2 cells. mRNA and protein expressions of TNF-α were determined by qRT-PCR and Western blotting,respectively,and concentration of TNF-α in supernatant was measured by ELISA, number of lymphocyte penetrating the membrane was measured by Transwell chamber. Results:Compared with control group,mRNA and protein expressions of TNF-α were significantly increased (P < 0. 05),concentration of TNF-α in supernatant was significantly increased (P < 0. 05),and number of lymphocyte penetrating the membrane was significantly increased in Fn group (P < 0. 05). miRNA sequencing and qRT-PCR results showed that expression of miR-181b was significantly decreased in Fn group than in control group (P < 0. 05). Compared with control group,mRNA and protein expressions of TNF-α were significantly decreased in miR-181b mimics + Fn group (P < 0. 05),however,mRNA and protein expressions of TNF-α were significantly increased in miR-181b inhibitor group (P < 0. 05). Bioinformatics tools and Luciferase assay confirmed that TNF-α might be the target gene of miR-181b in Caco-2 cells. Conclusions:Fn can up-regulate the expression of TNF-α by inhibiting miR-181b in Caco-2 cells and recruiting lymphocytes to form an inflammatory microenvironment.