Periosteal chondroma at birth.

Periosteal chondroma is a slow-growing, cartilaginous, surface tumor that usually occurs in the second and third decades of life. The youngest reported age at diagnosis is 5 years. Marginal excision is the treatment of choice. We report a case of a periosteal chondroma noted at birth and treated conservatively. This report expands the age range of periosteal chondroma to include neonates and suggests a role for observation in its management.

Giant congenital melanocytic nevus with underlying hypoplasia of the subcutaneous fat.

A 17-week-old boy with a giant congenital melanocytic nevus (GCMN) of the left lower extremity was noted to have a reduction in circumference of the left lower extremity relative to the contralateral side. The skin overlying the GCMN was persistently warm when compared with the surrounding and contralateral skin. Comparative plain radiography, ultrasonography, and magnetic resonance imaging showed fat hypoplasia of the left lower extremity, with bone and muscle appearing unaffected. The possible role of cytokines produced by the nevus in fat hypoplasia in GCMN is discussed.

Treatment of an aneurysmal bone cyst of the spine by radionuclide ablation.

We report the nonoperative treatment of a recurrent, multilevel spinal aneurysmal bone cyst by injection of 32P chromic phosphate colloid into the cyst. The patient was then followed up with serial CT examinations, which showed stabilization and progressive ossification within the lesion. The rationale, alternatives, and possible contraindications to radionuclide ablation of spinal aneurysmal bone cysts are discussed.

The magnetic resonance imaging of musculoskeletal hemorrhage.

Hematomas in the extremities can present clinically as a soft tissue mass. Hematomas can usually be distinguished from neoplasia on MR by the signal patterns of hemoglobin breakdown products, which are dependent on the chemical bonding and oxidation state of hemoglobin iron. Beginning with a discussion of relevant atomic electronic structure, this review will examine how oxyhemoglobin, deoxyhemoglobin, methemoglobin, and hemosiderin, the principal iron compounds occurring in the various stages of a hematoma, affect its appearance on MRI.

Three-dimensional computed tomography in the assessment of congenital scoliosis.

OBJECTIVE: Patients with congenital vertebral anomalies frequently are afflicted with kyphoscoliosis, with the curvatures often being severe and progressive. Spinal fusion almost always is the treatment of choice in such patients. This report examines the use of three-dimensional computed tomography (3D CT) in the preoperative investigation of patients with congenital scoliosis. DESIGN AND PATIENTS: Twelve spinal CT examinations on 11 pediatric patients with congenital scoliosis underwent image processing to produce 3D images. The 3D images were compared with both the axial sections from the CT examinations and multiplanar reformations with regard to the detection of malformations liable to cause progression of scoliosis (i. e., hemivertebrae and unsegmented bars). RESULTS AND CONCLUSIONS: In six of the 12 cases, the 3D images provided improved depiction of the congenital anomalies and their interrelationships compared with planar CT images. This work suggests that 3D CT can be a useful tool in the assessment of patients with congenital scoliosis.

Deletion 1p in a low-grade chondrosarcoma in a patient with Ollier disease.

Ollier disease is an uncommon, nonhereditary developmental disorder affecting enchondral ossification. Cytogenetic analysis of low-grade chondrosarcoma in a patient with Ollier disease (multiple enchondromatosis) revealed an interstitial deletion, del(1)(p11p31.2), as the only chromosome abnormality. This is the first cytogenetic study of a chondrosarcoma in a patient with Ollier disease. Such patients are at risk of developing chondrosarcoma and, because del(1p) is frequent in chondrosarcoma, it is suggested that this cytogenetic finding is associated with early chondrosarcomatous transformation.

Evaluation of an ultrasmall superparamagnetic iron oxide in MRI in a bone tumor model in rabbits.

Ultrasmall superparamagnetic iron oxides (USPIOs) are a class of MRI contrast agents having moderately selective affinity for the reticuloendothelial cells of lymph nodes and bone marrow. This study evaluated a USPIO preparation, Combidex (Code 7227), in MRI of a rabbit bone tumor model. VX2 carcinoma implanted into the tibial marrow of nine subject rabbits was studied. After tumor growth, the subjects underwent MRI of their lesions both before and after intravenous administration of Code 7227. Code 7227 was judged subjectively to conspicuously reduce the signal intensity of normal marrow on some pulse sequences. A hypointense zone outlined the tumor margins on postcontrast imaging, which allowed improved visualization of the soft tissue component of the larger lesions. Accumulation of the contrast agent in a zone of inflammation outside the tumor margin was demonstrated on histologic sections of the lesions. Code 7227 deserves additional study as a potential contrast agent for MRI of bone tumors.

Evaluation of suspected osteoid osteoma.

A technique of computed tomography with intravenous contrast has proven useful in the differentiation between osteoid osteoma and other similar appearing lucent lesions of bone in 6 cases. The clinical evaluation of benign appearing radiolucent lesions of long bones has been greatly improved by the use of modern imaging techniques. The differential diagnosis often is narrowed to osteoid osteoma and osteomyelitis based on plain radiographs, computed tomography, or magnetic resonance imaging. The enhancement of the lucent center of the lesion was plotted against time. The rapid uptake of contrast medium by the osteoid osteoma was in sharp contrast to the much slower enhancement in osteomyelitis. The establishment of a preoperative diagnosis enabled the surgeon to excise the lesion without a biopsy. Histologic review verified the preoperative diagnosis in all cases.

Surgical considerations in a diagnostic imaging evaluation of musculoskeletal masses.

The management of patients with soft-tissue masses necessitates careful assessment and appropriate use of investigational tools to obtain a diagnosis. The interaction among surgeons, radiologists, and pathologists allows adequate staging of soft-tissue tumors and better planning of the definitive treatment. The ability of MR imaging to maximize contrast between normal and tumor tissues in any desired plane makes it usually the best cross-sectional imaging modality in the preoperative staging of soft-tissue masses.

Axial skeletal changes in paralysed patients may mimic ankylosing spondylitis.

Patients with paralysis may develop radiographic changes in the axial skeleton and sacroiliac joints that resemble those seen in ankylosing spondylitis. These similarities can result in confusion when evaluating paralysed patients with back pain. We report on a patient with paralysis secondary to amyotrophic lateral sclerosis who developed back pain, apparent sacroiliac joint fusion, and a 'bamboo spine', leading to the misdiagnosis of ankylosing spondylitis. Serial radiographs of the bony changes in our patient are presented, along with a brief review of the literature on axial skeletal abnormalities in paralysis and a discussion of the subtle changes that distinguish immobilization spondyloarthropathy from ankylosing spondylitis.

Involvement of 10q22 and 11q13 in hibernoma.

A hibernoma studied cytogenetically had the karyotype 46,XY,t(9;10;11)(q34;q22;q13),t(17;19) (q21.3;q13). The findings are discussed and compared with those of the previous case described in the literature.

Imaging of atypical lipomas of the extremities: report of three cases.

Atypical lipomas are soft tissue neoplasms which differ from simple lipomas in that they consist of mature fat cells interspersed with occasional areas containing a variable admixture of multinucleated cells, collagen bundles, and adipocytes with large, hyperchromic nuclei. Although these histopathologic features resemble those of liposarcoma, atypical lipomas occurring in the extremities differ from liposarcoma because they have no tendency for distant metastases. Three patients with atypical lipomas involving the posterior compartment of the thigh are presented. The lipomas were imaged with computed tomography (CT) and magnetic resonance imaging (MRI), using a 0.15-T whole body imager. Although all lesions appeared largely lipomatous, the three lesions simulated liposarcoma on both CT and MRI. On CT, each lesion demonstrated small areas of confluent soft tissue density; these areas were hyperintense with adipose tissue on strongly T2-weighted MRI. We conclude that atypical lipoma of the extremities may not be distinguishable from liposarcoma on imaging and that biopsy is necessary for differentiation.

High-resolution CT of the wrist: initial experience with scaphoid disorders and surgical fusions.

We performed high-resolution CT scans on 30 wrists in 27 patients with either previous surgical intercarpal fusion or known or suspected scaphoid abnormalities. Most examinations used the same protocol: contiguous 1.5-mm axial sections parallel to the long axis of the body of the scaphoid, small reconstruction circle, and bone reconstruction algorithm. Fifteen patients were evaluated for union of previous surgical carpal fusions; eight patients were evaluated for healing of scaphoid fractures; and the other four patients had miscellaneous disorders, including a midcarpal dislocation with a scaphoid fracture. High-resolution CT clearly showed whether the carpal fusions were united. In addition, metallic fixation devices were easy to locate and did not significantly degrade image quality. Osseous union of healing scaphoid fractures was reliably assessed. We conclude that high-resolution CT of the wrist is a useful method for evaluating surgical carpal fusions and various disorders of the scaphoid.