Abstract
BACKGROUND: Gastrointestinal stromal tumors (GISTs) rarely present with predominantly cystic changes. Here, we report a case of giant GIST of the stomach with predominantly cystic changes in a 74-year-old female patient. CASE PRESENTATION: The tumor was 10 cm × 15 cm in size and positive for CD117, H-caldesmon, and DOG-1. Complete surgical resection was performed without regional lymphadenectomy. The patient recovered uneventfully and no recurrence occurred. CONCLUSIONS: The case illustrates that GIST with cystic changes should be considered in the diagnoses of hepatic and pancreatic lesions. Furthermore, immunohistochemistry with CD117, DOG1, and other molecular markers is critical for diagnosis of GIST of the stomach and facilitates optimization of treatments for GIST.