<prompt> A 50 year old lady presented with a 3 month history of pain in the lower third of the right thigh. There was no local swelling; tenderness was present on deep pressure. Plain X-rays showed an ill-defined intra medullary lesion with blotchy calcification at the lower end of the right femoral diaphysis, possibly enchondroma or chondrosarcoma. Sections showed a cailaginous tumor. Which of the following histological featuresif seen would be most helpful to differentiate the two tumours?Focal necrosis and lobulationTumor permeation between bone trabeculae at peripheryExtensive myxoid changeHigh cellularity  <response>: High cellularity 