desmoplastic reaction
Fibrous tissue response surrounding neuroendocrine tumors, particularly common in small bowel primaries.
Full Definition
Desmoplastic reaction refers to the proliferation of fibrous connective tissue (desmoplasia) that develops around certain neuroendocrine tumors, most characteristically seen with small bowel NETs. This reactive fibrosis can cause significant clinical complications including bowel obstruction, mesenteric fibrosis, and vascular compromise even when the primary tumor is small. The desmoplastic response appears to be mediated by tumor-secreted factors and can be disproportionate to tumor size. Recognition of this phenomenon is crucial for surgical planning and understanding why small bowel NETs may present with obstructive symptoms despite minimal tumor burden.
Usage
Usage note: Most commonly associated with ileal NETs; less frequent in other NET subtypes.
In Context
- "CT imaging revealed extensive desmoplastic reaction in the mesentery despite a 1.2 cm primary tumor." — radiology report
- "The desmoplastic reaction required careful dissection to preserve bowel viability during resection." — operative note