Pathologic neovascularization in cartilage tumors.

Tumor-induced angiogenesis is necessary to sustain radial growth of tumors. Increased microvascularity has been correlated with increased metastatic potential in breast, gastrointestinal, and gynecologic tumors, but has not been well studied in cartilaginous tumors. Grade II and Grade III chondrosarcomas have increased metastatic potential compared with Grade I tumors. One reason for this may be pathologic neovascularization. The purpose of the current study was to quantify the microvessel density of cartilage tumors. Seven Grade III, 17 Grade II, and eight Grade I chondrosarcomas, and 22 benign cartilage tumors were examined. Specimens were stained with antiCD34 antibody. Microvessel densities then were determined by direct counting and estimated using the Chalkley technique. Microvessel densities for Grade III and Grade II chondrosarcomas were 45.9 and 46.2 per high-power field and for Grade I and benign tumors the microvessel densities were 9.3 and 10.3. Microvessel densities of the aggressive tumors (Grades III and II) were greater than the microvessel densities of the nonaggressive tumors (Grade I and benign). Chalkley estimates confirmed the results. Microvascularity in cartilage tumors correlates with their biologic aggressiveness and seems promising as a variable to help with histopathologic grading and as a target for new treatment modalities.