Aneurysmal Bone Cyst : Morphology
Aneurysmal Bone Cyst (ABC) - Microscopic Features: Higher magnification view from a solid focus of an ABC. Numerous osteoclast-type giant cells are present in a background of bland spindle cell proliferation. Mitotic activity is frequently increased (although this field shows no mitoses). There are no atypical mitoses and no cytologic atypia.