RT Book, Section A1 Randall, R. Lor A1 Ward, Russell A1 Hoang, Bang H. A2 Skinner, Harry B. A2 McMahon, Patrick J. SR Print(0) ID 57813481 T1 Chapter 5. Musculoskeletal Oncology T2 Current Diagnosis & Treatment in Orthopedics, 5e YR 2014 FD 2014 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-159075-4 LK accesssurgery.mhmedical.com/content.aspx?aid=57813481 RD 2024/03/29 AB Musculoskeletal oncology is a field of medicine that involves the diagnosis and management of neoplastic conditions affecting the musculoskeletal system. This not only entails neoplasia of mesenchymal origin (derived from embryonic mesoderm), but also metastatic carcinoma and a variety of pseudotumorous conditions. Mesenchymal tumors are an extremely heterogeneous group of neoplasms including over 200 benign conditions and 90 types of sarcoma, and so the majority of this chapter is dedicated to them. The relative incidence of benign to malignant disease is 200:1. These tumors are classified histomorphologically based on features of differentiation, but there is considerable overlap. It is favorable to consider these separate conditions as points on a continuum, rather than entirely distinct entities. Classification, nevertheless, is important because it may yield insight to the behavior, treatment response, and overall prognosis. Benign disease, by definition, behaves in a nonaggressive fashion and exhibits little tendency to locally recur or metastasize. Sarcomas (malignant tumors of mesenchymal origin), however, can be rapidly destructive, have metastatic potential, and have a tendency to locally recur.