20-43: Tumors & Tumor-Like Lesions of Bone

ESSENTIALS OF DIAGNOSIS

GENERAL CONSIDERATIONS

Primary tumors of bone in adults are relatively uncommon in comparison with secondary or metastatic neoplasms. They are, however, of great clinical significance because some grow rapidly and metastasize widely.

Although tumors of bone have been categorized classically as primary or secondary, there is some disagreement about which tumors are primary to the skeleton. Tumors of mesenchymal origin that reflect skeletal tissues (eg, bone, cartilage, and connective tissue) and tumors developing in bones that are of hematopoietic, nerve, vascular, fat cell, and notochordal origin should be differentiated from secondary malignant tumors that involve bone by direct extension or hematogenous spread. Because of the great variety of bone tumors, it is difficult to establish a satisfactory simple classification of bone neoplasms.

CLINICAL FINDINGS

Persistent skeletal pain and swelling, with or without limitation of motion of adjacent joints or spontaneous fracture, are indications for prompt clinical, radiographic, laboratory, and possibly biopsy examination. Radiographs may reveal the location and extent of the lesion and certain characteristics that may suggest the specific diagnosis. The so-called classic radiographic findings of certain tumors (eg, punched-out areas of the skull in plasma cell myeloma (eFigure 20–41), "sun ray" appearance of osteogenic sarcoma (eFigure 20–42), and "onion peel" effect of Ewing sarcoma [eFigure 20–43]), although suggestive, are not pathognomonic. The age of the patient, the duration of complaints, the site of involvement and the number of bones involved, and the presence or absence of associated systemic disease—as well as the histologic characteristics—must all be considered for proper management.