desmoplastic

Desmoplastic is an adjective used in pathology and oncology to describe a tissue reaction in which fibrous or connective tissue proliferates around a lesion, especially a tumor. The process, desmoplasia, results in a dense, collagen-rich stroma that is often populated by activated fibroblasts or myofibroblasts and an altered extracellular matrix. The desmoplastic stroma forms a barrier around the neoplasm and is a characteristic feature of certain cancers and other lesions.

Desmoplasia is driven by signaling from tumor cells to stromal cells, notably through transforming growth factor-beta and other cytokines, which recruit cancer-associated fibroblasts and promote extracellular matrix deposition. The resulting tissue often appears firm or “scirrhous” on gross examination and can influence the tumor microenvironment by increasing stiffness and reducing vascularity.

In pathology, desmoplastic tumors are described as having a prominent stromal component. Examples include desmoplastic melanoma, desmoplastic small round cell tumor, desmoplastic infantile ganglioglioma, and desmoplastic forms of pancreatic ductal adenocarcinoma and breast carcinoma. The desmoplastic reaction can affect tumor biology by altering stiffness, diffusion of nutrients and drugs, and interactions with immune cells, and it may influence prognosis and therapeutic response depending on tumor type.

Desmoplastic changes are distinct from scar tissue formed after healing. They reflect an ongoing interaction between tumor cells and the surrounding stroma and are used diagnostically to characterize and differentiate lesions in surgical pathology. The term desmoplastic derives from Greek roots meaning bond or formation.