Benign osteoblastoma.A category of osteoid- and bone-forming tumors other than classical osteoid osteoma, which may be mistaken for giant-cell tumor or osteogenic sarcoma

T SEEMS worth while at this time to delineate I more clearly the pathological nature and appropriate treatment of certain benign tumors of bone of osteoblastic derivation, other than osteoid osteoma and osteoma, so-called.Their recognition is of practical importance in that they may be mistaken for giant-cell tumor or osteogenic sarcoma and, as such, treated more aggressively than is required.T h e writer has had occasion within the past several years to observe material from eleven pertinent instances encountered in long bones, the vertebral column, and other sites that will serve as the basis for discussion.These benign osteoblastic tumors include the ones previously called "osteogenic fibroma" by the writer, as well as those referred to provisionally as "other osteoid-tissue-forming tumors" in his classification of primary tumors of bone.5-7He has come to feel that there is no fundamental difference between these two subgroups and that for all practical purposes they comprise a single category of benign osteoid-and bone-forming tumors, which may be appropriately designated as benign osteoblastoma.With reference to relevant cases previously published under other titles, it seems altogether probable that the unusual neoplasm described by Jaffe and hfayer-' as an "osteoblastic osteoid tissue-forming tumor 01 a metacarpal bone" falls logically into this category.Furthermore, most of the tumors re-