A Serosa-Originated Gastric Stromal Tumor Misdiagnosed by Ultrasonography and Frozen Section Pathology: A Case Report

Lizhong Ren,1,* Hongrong Qian,1,* Junsen Wang,2 Piaopiao Jin,3 Qida Hu,4 Jiajie Yu,5 Xin Zhang,6 Yun Zhang,4 Haifeng Huang5 1Department of Ultrasound, Shengzhou People’s Hospital, Shaoxing 312400, People’s Republic of China; 2Department of Pathology, Shengzhou People’s Hospital, Shaoxing 312400, People’s Republic of China; 3Health Management Center, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, People’s Republic of China; 4Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, People’s Republic of China; 5Department of Surgery, Shengzhou People’s Hospital, Shaoxing 312400, People’s Republic of China; 6Department of Radiology, Shengzhou People’s Hospital, Shaoxing 312400, People’s Republic of China*These authors contributed equally to this workCorrespondence: Junsen WangDepartment of Pathology, Shengzhou People’s Hospital, 666 Dangui Road, Shaoxing 312400, People’s Republic of ChinaTel +86 575 8333 8221Email junsenwang@outlook.comHaifeng HuangDepartment of Surgery, Shengzhou People’s Hospital, 666 Dangui Road, Shaoxing 312400, People’s Republic of ChinaTel +86 575 8333 8570Email 18241425@qq.comAbstract: Gastric gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm, typically arising from the muscularis propria layer of the stomach wall. Serosa-derived GIST is rarely seen and has not been reported yet. A 49-year-old Chinese female was presented with marked abdominal distension. Ultrasonography revealed a retroperitoneal tumor adjacent to the stomach wall with an intact structure of five echo layers, indicating a non-stomach tumor origin. Preoperative radiological studies suggested tight tumor-stomach adjacency, which was confirmed by intraoperative dissection. Initial frozen section indicated a pathological diagnosis of spindle cell tumor, which turned out to be a gastric GIST originated from the serosa layer of the stomach wall. The current case demonstrates the rare occurrence of serosa-derived GIST. This case also suggests difficulties in preoperative diagnosis of gastric GISTs, especially when uncommon pathological conditions like rare tumor origins were presented.Keywords: gastric gastrointestinal stromal tumor, serosa layer, schwannoma, misdiagnosis