Multiple Succinate Dehydrogenase-Deficient Gastrointestinal Stromal Tumors of the Stomach: A Case Report

Abstract

BACKGROUND Gastrointestinal stromal tumors (GISTs) are a rare subset of gastrointestinal neoplasms, with approximately 85% of cases being characterized by genetic alterations in either the KIT gene or the platelet-derived growth factor receptor alpha (PDGFRA) gene. In contrast, succinate dehydrogenase-deficient gastrointestinal stromal tumors (SDH-deficient GIST) account for only 5-10% of cases. SDH-deficient GISTs is a rare form of gastrointestinal tumor, predominantly affecting young people and women. It typically presents with multifocal lesions, has a tendency to invade lymph nodes, follows an indolent course, and is poorly responsive to imatinib; sunitinib and regorafenib may be effective against it. For patients with resectable lesions, surgical intervention remains the cornerstone of treatment. CASE REPORT A 26-year-old male patient was admitted with the presenting symptom of melena. Subsequent diagnostic evaluations revealed the presence of multiple gastric neoplasms. He underwent laparoscopic distal gastrectomy for multiple gastric tumors and postoperative pathology was consistent with GIST, SDH-deficient type. Genetic testing for KIT, PDGFRA, KRAS, NRAS, BRAF, SDHA, SDHB, SDHC, SDHD, and NF1 showed no mutations. The patient is still being followed and no evidence of relapse has been found 6 months postoperatively. CONCLUSIONS Although SDH-deficient GISTs generally exhibit indolent biological behavior, clinically significant manifestations such as gastrointestinal bleeding, as observed in this case, occasionally occur. The postoperative resolution of hemorrhagic symptoms in this patient demonstrated the therapeutic efficacy of surgical intervention. This case underscores the importance of timely surgical management while highlighting the need for improved diagnostic precision and optimized treatment algorithms. The present report provides valuable clinical insights for prognostic evaluation and clinical decision-making in SDH-deficient GISTs, while also offering a reference for future investigations into novel targeted therapies.

Figure 1

Radiographic images. Abdominal CT scan showed multiple round masses (arrows) in the gastric body and antrum, with the largest measuring 3.7×2.8 cm. These masses protruded beyond the gastric contour, exhibiting moderate and uneven enhancement in some areas. Additionally, the anterior surface of the pancreas was compressed by the masses.

Figure 2

Digestive endoscopy and endoscopic ultrasound (EUS) images. Gastroscopy revealed 2 small polyps (0.5 cm to 0.6 cm) in the lesser curvature of the stomach, an irregular submucosal elevation (2.0×1.8 cm) with smooth mucosa on the posterior wall of the lower stomach, and a spherical submucosal elevation (3.5×3.0 cm) with a dark red blood clot in the lesser curvature. (A) Gastric antrum; (B) Gastric body (tumors are marked with arrows); (C) Gastric antrum (circles indicate tumors) (EUS); (D) Perigastric lymph node (circles) (EUS).

Figure 3

Tumor of the gastric antrum (circles) (endoscopic ultrasound-elastography).

Figure 4

Pathological images. (A, B) H&E stain ×100 magnification. The tumor tissue exhibits a diffuse distribution with tightly packed cells, occasionally arranged in sheet-like or fascicular patterns. The tumor margins are relatively well-defined, with some areas showing fibrous stromal separation and sparse vascular distribution. (C, D) H&E stain ×400 magnification. The tumor cells are round-to-oval, with mildly eosinophilic cytoplasm. The nuclei are large, with distinct nuclear membranes and visible nucleoli. Nuclear atypia is evident, with irregular chromatin distribution and occasional hyperchromatic nuclei.

Figure 5

Pathological images. Immunohistochemistry showed positivity for CD117 and Dog-1, with negative results for PDGFRA and SDHB. The Ki-67 index was approximately 4%. (A) CD117(+); (B) Dog-1(+); (C) PDGFRA(−); (D) SDHB(−).