AUTHOR=Luo Yuehao , Wu Ying , Chang Xiaona , Huang Bo , Luo Danju , Zhang Jiwei , Zhang Peng , Shi Heshui , Fan Jun , Nie Xiu TITLE=Identification of a novel FGFR2-KIAA1217 fusion in esophageal gastrointestinal stromal tumours: A case report JOURNAL=Frontiers in Oncology VOLUME=12 YEAR=2022 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.884814 DOI=10.3389/fonc.2022.884814 ISSN=2234-943X ABSTRACT=Background

Gastrointestinal stromal tumours (GISTs) rarely arise in the esophagus. The clinical course and treatment options for esophageal GISTs are poorly understood because of their rarity. In general, the mutation spectrum of esophageal GISTs resembles that of gastric GISTs. Wild-type (WT) GISTs lacking KIT and PDGFRA gene mutations occasionally occur in adults; primary esophageal GISTs are commonly WT.

Case presentation

Herein, we report the case of a 41-year-old female patient who presented with a 1-week history of anterior upper chest pain. Chest computed tomography revealed a 3.7 cm × 2.8 cm × 6.7 cm soft tissue mass in the right posterior mediastinum adjacent to the esophagus. The patient underwent thoracoscopic mediastinal tumor resection and was subsequently diagnosed with an esophageal GIST. Neither KIT nor PDGFRA mutations were detected by Sanger sequencing; however, next-generation sequencing (NGS) identified an FGFR2-KIAA1217 gene fusion in the tumor tissue. No relapse was observed in this patient during the 8-month treatment-free follow-up period.

Conclusion

To the best of our knowledge, this report is the first to describe an FGFR2-KIAA1217 fusion in a patient with a quadruple WT esophageal GIST. When WT KIT/PDGFRA GISTS are suspected, intensive genetic analysis is recommended, and obtaining a better molecular characterization of these tumours might reveal novel therapeutic avenues.