Imaging and clinicopathological features of a high-risk gastric stromal tumor: a case report

To report upon the imaging and clinicopathological characteristics of a high-risk gastric stromal tumor (GST).

A patient diagnosed with a GST at Shanghai Xuhui District Dahua Hospital and Shanghai Eighth People's Hospital in November 2021 was retrospectively analyzed. Clinical data, pathological features, immunohistochemical markers, c-kit/PDGFRA gene mutation status, and CT/MRI findings were collected.

A 70-year-old male with a long history of smoking and alcohol use was diagnosed with a GST during a routine physical examination. The tumor exhibited high-risk features: a diameter of 7 cm, a mitotic count of 8/50 high-power fields, and location involving the submucosa and muscular layer. Immunohistochemistry revealed strong positivity for CD117 and CD34, positivity for DOG1, and a Ki-67 index <10%. Gene mutation analysis identified a heterozygous mutation in exon 11 of the c-kit gene (c.1676T>A p.Val559Asp), with no mutations detected in PDGFRA. Histologically, the tumor showed marked atypia with solid and cord-like growth patterns and conspicuous mitotic figures. Imaging demonstrated heterogeneous enhancement, ill-defined borders, irregular gastric wall thickening, calcification, and cystic/hemorrhagic changes. Notably, the patient remained recurrence- and metastasis-free for 4 years following surgical resection and adjuvant imatinib therapy.

This case highlights the integration of pathological features, c-kit exon 11 mutation status, and imaging findings in the diagnosis and management of high-risk GSTs. The 4-year recurrence-free survival confirms the effectiveness of risk-stratified adjuvant therapy with imatinib.