microvascular proliferation
Pathological increase in small blood vessels with endothelial hyperplasia, a defining feature of glioblastoma.
Full Definition
A histopathological hallmark of glioblastoma characterized by abnormal proliferation of endothelial cells and smooth muscle cells within tumor vasculature, often forming glomeruloid structures or multilayered vessel walls. This feature, along with necrosis, distinguishes glioblastoma from lower-grade astrocytomas in the WHO grading system. The proliferating vessels show increased cellularity, irregular caliber, and may form complex tufted or glomeruloid patterns that contribute to the aggressive nature and poor prognosis of these tumors.
Usage
Usage note: Essential criterion for glioblastoma diagnosis; must be distinguished from reactive vascular changes.
In Context
- "Prominent microvascular proliferation with glomeruloid features confirmed the diagnosis of glioblastoma." — WHO grade IV astrocytoma diagnosis
- "The tumor showed extensive microvascular proliferation throughout, distinguishing it from grade III astrocytoma." — Grading assessment