A Rapid Progressive Submucosal Tumor Diagnosed as an Idiopathic Pseudoaneurysm in the Subserosal Gastric Wall: A Case Report.

INTRODUCTION

The classic differential diagnosis of a progressive gastric submucosal tumor (SMT) includes gastrointestinal stromal tumor (GIST), lymphoma, and leiomyoma. But idiopathic pseudoaneurysm is seldom seen. We report the first case of a gastric idiopathic pseudoaneurysm that could not be diagnosed preoperatively.

CASE PRESENTATION: An 83-years-old female was referred to our department (Center of Gastroenterology and Oncology, IMS Ota Chuo General Hospital) due to a 39 mm gastric mass accidentally found by CT scan. This mass had rapidly increased in size from 26 to 39 mm in 4 months. She had been seeing cardiology for atrial fibrillation on direct oral anticoagulant drug (DOAC) and chronic heart failure. Diffusion weight image (DWI) of MRI showed a high-intensity area in this mass. We diagnosed rapid progressive SMT and performed distal gastrectomy. The pathological finding was a pseudoaneurysm in the subserosal layer. Since she had no history of trauma or vasculitis, we diagnosed it as an idiopathic pseudoaneurysm. DOAC might contribute to the formation of this pseudoaneurysm. She had no recurrence in 3 years of follow up. To the best of our knowledge, this is the first reported case.

CONCLUSIONS

Gastroenterologists should consider pseudoaneurysm in the differential diagnosis of rapid progressive SMT.