A benign bone lesion composed of vascular-like dilated spaces surrounded by compressed fibrotic stroma showing focal interstitial hemorrhage with very
occasional osteoclastic type giant cells. Picture in correlation with radiologic appearance is consistent with aneurysmal bone cyst. No evidence of specific granulomas. No evidence of malignancy.
Right proximal tibia lytic lesion.
Soft tissue and bone fragments collectively measured 7.8x6.5x1.5 cm, the largest measured 3x3x1.5 cm.
Right proximal tibia lyric lesion, biopsy: