Exogastric leiomyosarcoma with ultrastructural analysis

A 50-year-old man was found to have a large exogastric leiomyosarcoma during exploratory laparotomy for a bleeding duodenal ulcer. Although the tumor appeared grossly malignant and was associated with small bowel metastases, its light microscopic appearance was relatively benign. Electron microscopy helped to established the diagnosis of gastric leiomyosarcoma.