Pathology: osteoblastoma

Osteoblastoma

  • Fibrous-osseous neoplasm

  • Anastamosing trabeculae of woven bone with prominent osteoblastic rimming

  • Polygonal-epithelioid cells with abundant eosinophilic cytoplasm; ovoid nuclei with small nucleoli, minimal pleomorphism, and inconspicuous mitotic activity

  • Interspersed osteoclast-type multi-nucleated giant cells

  • IHC: SATB2

Prior history of "osteoid osteoma" treated by radiofrequency ablation

Osteoblastoma

  • Fibrous-osseous neoplasm

  • Anastamosing trabeculae of woven bone with prominent osteoblastic rimming

  • Polygonal-epithelioid cells with abundant eosinophilic cytoplasm; ovoid nuclei with small nucleoli, minimal pleomorphism, and inconspicuous mitotic activity

  • Interspersed osteoclast-type multi-nucleated giant cells

  • IHC: SATB2