Fig. 2: Additional morphologic findings.

Most cases had at least one cell with multiple nuclei involving one lacunar space (2A, case 5, ×40) and rare cells had numerous nuclei (2A inset, case 2, ×40). Three cases had easily identifiable mitotic figures (2B, case 9, ×40), and three cases had associated bone formation, suggestive of endochondral ossification (2C, case 8, ×20).