ABSTRACT
This chapter is concerned with the pathological aspects of benign and primary malignant bone neoplasms. Developmental or tumour-like lesions will only be mentioned in the differential diagnoses. Recently, the historical distinction of gross tissue dysplasias and hamartomas from neoplasms has become progressively blurred. The classification of certain mass-forming cellular proliferations as gross tissue dysplasias and hamartomas was based on gross and microscopic morphology, but in large part due to the advent of molecular biological technologies the genetic bases of these lesions have been
discovered causing many of them to be reconsidered as neoplastic processes. In particular, the discovery of specific mutations and the demonstration of monoclonality in lesions such as aneurysmal bone cyst, fibrous dysplasia and osteochondroma support the view that these are all true neoplasms rather than the variably held historical views that these were developmental abnormalities, dysplasias and hamartomas respectively. As such, these lesions will be considered in this chapter as true neoplasms. This chapter will only consider primary bone tumours, and will not concern itself with the clinically important field of metastatic bone disease. Detailed discussion of treatment options is discussed in subsequent
chapters. This chapter is limited to the pathology of the more common benign and malignant primary bone tumours. Table 81.1 lists the bone tumour classification accepted recently by the World Health Organization (WHO).1 The tumours that are discussed in this chapter are marked with an asterisk. Before specific entities are described, brief overviews of the epidemiology, clinical presentation and radiological features and staging of bone tumours is merited, as well as a consideration of the histology of bone structure and remodelling.
