Microvasculature and VEGF expression in cartilaginous tumors

We examined the microvasculature and VEGF expression in 26 cartilaginous le sions (CL) including 5 enchondromas, 9 grade 1 chondrosarcoma (CS), 6 grade 2 CS, 4 grade 3 CS, 1 mesenchymal, and 1 myxoid chondrosarcoma. The degree of neovascularization was measured by counting microvessels on H&E and fac tor VIII related antigen immunostained slides. Vessels were divided into pe ricartilage vessels (PCV) and intracartilage vessels (ICV). PVC comprised v essels around the lobules or invading the lobules but themselves surrounded by noncartilaginous stroma (ie, fibrous stroma); ICV consisted of those ve ssels present inside the tumoral nodules and in direct apposition with mali gnant cells or tumoral stroma. A direct correlation was seen between histol ogical type and grade of CS and pericartilage vessels. In contrast, ICV wer e found only in higher-grade CS, No enchondromas and only 1 of 9 grade 1 CS had ICV. This patient had Oilier's disease. All but 2 of the grade 2 CS sh owed ICV (average, 20.5). The exceptions were predominantly grade 1 CS with focal grade 2 areas and extensive areas of necrosis. All but 1 grade 3 CS had ICV, the exception being a case of metastatic CS to the lung. Malignant chondrocytes of high-grade lesions stained strongly for vascular endotheli al growth factor (VEGF), a potent angiogenic factor. The only high-grade tu mors that did not express VEGF did not show ICV either. Enchondromas and gr ade 1 CS, most without ICV, did not express VEGF. In summary, PCV are prese nt in all categories of tumoral cartilage and the number increases with his tological grade; ICV are found in high-grade lesions, and the exceptions sh ow extensive necrosis; VEGF expression by malignant chondrocytes is seen in high-grade lesions almost exclusively and among these in those lesions tha t showed intracartilage vessels. It is possible that PCV are involved in su pporting tumor growth, whereas ICV might be involved in the acquisition of metastatic potential by cartilage tumors. VEGF expression is strongly assoc iated with the presence of ICV. Copyright (C) 2000 by W.B. Saunders Company .