Osteoblastoma: a study of 12 cases.

This study comprises of 12 cases of osteoblastoma. There were 8 males and 4 females, with a mean age of 17.8 years. The vertebral column, including the sacrum was the most frequent site (10 of 12 cases). Radiologically the lesions were lytic, well circumscribed and expansile. The histology consisted of intercommunicating osteoid seams lined by plump osteoblasts with numerous intervening ectatic stromal vessels. Despite these characteristic features, the distinction of osteoblastoma from osteoblastic osteosarcoma can at times be very problematic. The lack of lace-like osteoid or sheets of osteoblasts, and inconspicuous mitotic activity are useful distinguishing features. The purpose of this communication is to highlight the microscopic features for the correct recognition of osteoblastoma and its distinction from other osteoid forming bone lesions.