How to Approach Bone Tumors Frank O’Dea December 20, 2002

Introduction If you try to look at hole/abnormality in bone without a system then you will get lost! Once you have a system that works and apply it every time then the diagnosis becomes self apparent or at the very least a rational plan of attack develops.

Don’t think like a shot gun!!!! Think of the age of the patient. Think of where the abnormality is …. or isn’t. Think of the tissue categories of tumors. Think in terms of benign, benign aggressive or malignant.

Tumor Tissue types Metastatic 90% Hematologic (Myeloma, Lymphoma, Leukemia 5%) Primary Mesenchymal Tumors 5%

Primary Bone Tumors Osteogenic Fibrous Chondroid Lipomatous Other *****These are the broad categories******

Osteogenic Benign: Osteoma, Osteoid Osteoma, Bone Islands Benign Aggressive: Osteoblastoma Malignant: Osteogenic Sarcoma

Fibrous Tumours Benign: Fibrous Cortical Defect, Non-Ossifying Fibroma, Fibroma of Bone. Benign Aggressive: Fibromatosis(desmoid), Ossifying Fibroma of bone, Fibrous Dysplasia. Malignant: Malignant Fibrous Histiocytoma of bone, Fibrosarcoma.

Chondroid Benign: Enchondroma, Peri-osteal Chondroma, Osteochondroma. Benign Aggressive: Chondromyxoid Fibroma, Chondroblastoma. Malignant: Chondrosarcoma.

Other Bone Tumors Benign: Bone Cyst, Ganglion, Hemangioma. Benign Aggressive: Giant Cell Tumor, Aneurysmal Bone Cyst, EOG. Malignant: Adamantinoma, Chordoma, Ewings.

Radiographic Features of the Various Tumors Benign: well circumscribed, narrow transition, no reaction, sclerotic border, ‘does one thing’. Benign Aggressive: neocorticalization, expansion, thinning of cortex, usually lytic, +/-reaction, +/- narrow zone of transition. Malignant: ++++reaction, large, permeative, moth eaten, ‘does more than one thing’. Conditions/Mets: more than one bone, symmetry.

Benign Features

Benign Aggressive Features

Malignant Features

Radiographic Tissue Identifiers Bone, Sclerosis, Calcification….. Osteoid. Popcorn, Arc Ring Calcification, Bright on T2, Low on T1….chondroid. Lytic, Low on T2, Low on T1….Fibrous. Lytic, well circumsribed, Bright T2, Dark T1……Cystic fluid. Fluid Fluid Levels….ABC

Sites of Tumors Diaphyseal: Ewings, Osteoid Osteoma, Mets, Adamantinoma, Fibrous Dysplasia Epiphyseal: Chondroblastoma, Clear Cell Chondrosarcoma, GCT, Ganglion of Bone. Metaphyseal: Everything!!!!!!

Age of Tumors 20>…..Osteogenic Sarcoma, Ewings. 40……GCT, Chondrosarcoma, MFH, Lymphoma, Mets. 60……Mets, Myeloma, Chondrosarcoma, late Osteogenic, MFH, Fibrosarcoma.