Intra-abdominal ectopic bronchogenic cyst with a mucinous neoplasm harboring a GNAS mutation: A case report  

作　　者：Takashi Murakami Hiroaki Shimizu Kazuto Yamazaki Hiroyuki Nojima Akihiro Usui Chihiro Kosugi KiyohikoShuto Shuntaro Obi Takahisa Sato Masato Yamazaki Keiji Koda 

机构地区：[1]Department of Surgery,Teikyo University Chiba Medical Center,Ichihara 299-0111,Chiba,Japan [2]Department of Pathology,Teikyo University Chiba Medical Center,Ichihara 299-0111,Chiba,Japan [3]Department of Internal Medicine,Teikyo University Chiba Medical Center,Ichihara 299-0111,Chiba,Japan

出　　处：《World Journal of Clinical Cases》2022年第24期8709-8717,共9页世界临床病例杂志

摘　　要：BACKGROUND Bronchogenic cysts are congenital cysts caused by abnormal sprouting from the ventral foregut during fetal life.They usually occur in the mediastinum or lung,but there are very rare cases of ectopic bronchogenic cysts that develop in the abdominal cavity.A unique intra-abdominal ectopic bronchogenic cyst with a mucinous neoplasm that was producing carcinoembryonic antigen(CEA),harboring a GNAS mutation,is reported.The present case may contribute to clarifying the mechanism of tumorigenesis and malignant transformation of ectopic bronchogenic cysts.CASE SUMMARY In 2007,a man in his 50s was incidentally found to have an intra-abdominal cystic mass,8 cm in diameter.Surgical resection was recommended,but he preferred to remain under observation.In 2020,his serum CEA level increased to 26.7 ng/mL,and abdominal computed tomography showed a 15 cm×12 cm,multifocal,cystic mass located predominantly on the lesser curvature of the stomach.Since malignancy could not be ruled out,he finally underwent surgical resection.Histologically,the cystic wall was lined by ciliated columnar epithelium,accompanied by bronchial gland-like tissue,bronchial cartilage,and smooth muscle.Part of the cyst consisted of atypical columnar epithelium with an MIB-1 index of 5%and positive for CEA.Moreover,a GNAS mutation(p.R201C)was detected in the atypical epithelium,leading to a diagnosis of an ectopic bronchogenic cyst with a low-grade mucinous neoplasm.The patient is currently undergoing outpatient follow-up without recurrence.CONCLUSION An extremely rare case of an abdominal bronchogenic cyst with a low-grade mucinous neoplasm harboring a GNAS mutation was reported.

关 键 词：Congenital hereditary and neonatal diseases and abnormalities Ectopic bronchogenic cyst Abdominal neoplasms GNAS mutation Carcinoembryonic antigen Case report 

分 类 号：R735[医药卫生—肿瘤]