Objective:

To report a case of gastric leiomyosarcoma (LMS) presenting with acute upper gastrointestinal hemorrhage and to highlight the diagnostic challenges associated with this rare malignancy.

Approach:

• Case Presentation: A 78-year-old female presented with acute upper gastrointestinal hemorrhage, severe anemia, and a submucosal gastric lesion identified through gastroscopy and CT imaging.
• Diagnostic Evaluation: Endoscopic biopsy and imaging were performed, revealing a spindle cell neoplasm, with further surgical resection confirming the diagnosis of gastric LMS.

Key Findings:

• Acute upper gastrointestinal hemorrhage can be the sole initial manifestation of gastric LMS.
• Preoperative imaging and superficial biopsy may underestimate the extent and aggressiveness of gastric LMS.
• Final pathology revealed a significant increase in the Ki-67 proliferation index from 25% to 50% post-surgery.

Interpretation:

The case emphasizes the need for careful diagnostic evaluation and postoperative surveillance in patients presenting with acute gastrointestinal bleeding, as it may indicate underlying malignancies like gastric LMS.

Limitations:

• The rarity of gastric LMS limits the generalizability of findings.
• The case report is based on a single patient, which may not represent broader clinical trends.

Conclusion:

Accurate diagnosis of gastric LMS requires thorough immunohistochemical analysis to differentiate it from gastrointestinal stromal tumors (GISTs), and close postoperative monitoring is essential.