A usually aggressive malignant neoplasm arising from the small intestine. It is characterized by the presence of spindle-shaped fibroblasts and collagenous stroma formation in a herringbone growth pattern. The disease is MONDO_0004028 (small intestinal fibrosarcoma). Also known as: fibrosarcoma of small bowel, fibrosarcoma of small intestine, fibrosarcoma of the small bowel, fibrosarcoma of the small intestine, fibrosarcoma, small intestine, small bowel fibrosarcoma, small intestine fibrosarcoma, small intestine fibrosarcoma (disease).