Pathology: simple bone cyst

Cyst with collagenous wall

Spindle-stellate cells with pale amphophilic cytoplasm; monomorphic ovoid nuclei and inconspicuous mitotic activity with abundant interspersed collagenous stroma

Sheets of foamy histiocytes; osteoclast-type giant cells; cholesterol clefts with foreign body giant cells; siderophages and haemosiderin deposition; sheets of hyalinized collagen

Cyst with collagenous wall

Spindle-stellate cells with pale amphophilic cytoplasm; monomorphic ovoid nuclei and inconspicuous mitotic activity with abundant interspersed collagenous stroma

Siderophages and haemosiderin deposition; sheets of hyalinized collagen