Primary solitary fibrous tumor of the stomach: A case report and a review of literature.

Rationale: Solitary fibrous tumors (SFTs) are spindle cell tumors that typically occur in the pleura and peritoneum, but very rarely in the stomach. To our best knowledge, there are only 10 cases reported in English literature. We reported a case of primary stomach SFT and summarized the characteristics of all previous cases, suggesting that pathologists and surgeons should include this disease in the differential diagnosis list of primary mesenchymal tumor of the stomach.

Patient Concerns: The patient suffered from epigastric pain for 5 months. Gastroscopy revealed a submucosa mass along the greater curvature centered on the gastric body. A repeat gastroscopy after 6 months showed a slight increase in mass size.

Diagnoses: Endoscopic ultrasound showed the mass in the middle and lower portion of the stomach body, measuring 3.1cm in diameter, with a smooth surface. The patient was initially diagnosed with a gastrointestinal stromal tumor by gastroscopy. However, the pathologic morphology and immunohistochemical staining of resected specimens after surgery support a diagnosis of primary gastric SFT.

Interventions: The patient underwent a laparoscopic gastric mass resection.

Outcomes: The patient returned to hospital after 3 months with no recurrence or postoperative complications. During the 18-month follow-up period, the patient did not experience any tumor recurrence or metastasis.

Lessons: This case teaches us that SFT should be included in the differential diagnoses of gastric primary spindle cell tumors, even though it is very rare in the stomach.