Fig. 3.

Histopathology slides (H&E, × 100). (A) Cystic spaces of varying sizes are filled with blood lined by plump spindle-shaped mononuclear cells and they are separated by cellular stroma. (B) Cystic vascular spaces are lined by fibroblasts and are devoid of endothelium. (C) Vascular space is lined by fibroblasts and the septa shows few osteoclastic giant cells without any evidence of atypia/necrosis/increased mitosis or granulomata. (D) Clusters of multinucleated osteoclastic giant cells seen admixed with spindle stromal cells. The giant cells are small with 3 to 6 nuclei and are lined along the septa. The above images are suggestive of aneurysmal bone cyst.