Evaluation of the child with a bone or soft-tissue neoplasm.

The prebiopsy evaluation of a child with a musculoskeletal neoplasm is the cornerstone for all subsequent treatment. A better understanding of the natural history of pediatric musculoskeletal tumors and an explosion in the development of sensitive new imaging modalities have significantly advanced the care of the child with a musculoskeletal pathologic condition. This article details the prebiopsy clinical and radiographic evaluation of the child or adolescent with a musculoskeletal neoplasm.

MRI of soft tissue tumors.

Magnetic resonance imaging (MRI) is the only noninvasive method of defining a soft tissue tumor. The extent of the tumor and the question of involvement or noninvolvement of various adjacent tissues and structures can be determined. This information, determination of lymphatic and distant metastatic spread, is invaluable for staging and management of the disease. Whether or not the tumor type can be reliably determined, or even whether the malignant or benign nature of the tumor can be ascertained on MRI examination, is open to question. Review of the literature indicates proponents on both sides of the issue. This review illustrates the imaging features that are relevant to suggesting a histologic diagnosis, and the pitfalls that are encountered in trying to determine the malignancy or benignity of a lesion. The clinical significance of these determinations is also discussed.

MR imaging of periosteal and cortical changes of bone.

The changes seen in the periosteum and cortical bone are fundamental radiographic features of bone disease. The basic radiographic findings used for diagnosis of bone lesions (patterns of cortical destruction and of periosteal new bone formation) can be well identified with magnetic resonance (MR) imaging. The authors used comparative radiographic, computed tomographic, and MR images to illustrate patterns of periosteal reaction (simple, laminated, spiculated, Codman triangle), geographic and permeative cortical destruction, cortical erosion, cortical expansion and continuity, and intraosseous and extraosseous calcification. The only feature not well demonstrated by MR imaging is pattern or extent of soft-tissue calcification. Although MR images are not required for diagnosis of most peripheral bone lesions, when they are obtained, these fundamental diagnostic features should not be ignored.

Case report 650: Grade II chondrosarcoma of the proximal end of the right femur.

A case is presented in which the conventional radiograph was suggestive of avascular necrosis. This impression remained unchanged inspite of an MRI examination that was more suggestive or replacement of marrow. The diagnosis of ischemic necrosis was strongly supported by the patient having previously established avascular necrosis in the opposite hip. The gross pathologic specimen showed only necrotic tumor, which mimicked avascular necrosis on the plain film. The importance of placing proper confidence in the MRI findings is thus emphasized. A classification and brief description of the various types of chondrosarcoma are included in the Discussion.

Idiopathic hypertrophic osteoarthropathy without pachyderma.

There are two types of hypertrophic osteoarthropathy; (a) the secondary type, by far the most common and usually associated with bronchogenic carcinoma; and (b) the idiopathic type, a rare disorder occurring predominantly in males and not associated with any known disease process. Both may be associated with peculiar skin changes known as pachyderma. When idiopathic hypertrophic osteoarthropathy (IHOA) is associated with pachyderma it is called pachydermoperiostosis. In extremely rare instances, IHOA may occur without pachyderma. Three such cases are described.