Marcia F. Blacksin

Synovial sarcoma: frequency of nonaggressive MR characteristics.

PURPOSE Our objective was to examine the MR characteristics of synovial sarcoma and determine the frequency of a nonaggressive imaging appearance. METHOD Fifteen patients with histologically confirmed cases of synovial sarcoma and prior MR examinations were seen. Retrospective analysis of imaging features included assessment of size, margins, homogeneity, internal architecture, T1- and T2-weighted signal intensities, and bone invasion. RESULTS Five of 15 patients (33%) had well circumscribed, homogeneous lesions with a mean length of 4.8 cm. The T1-weighted signal intensity was either isointense to muscle or greater in signal intensity than muscle. The T2-weighted images demonstrated signal intensity equal to or greater than fat. The remaining 10 lesions were larger (mean length of 11.3 cm) with mild to complex levels of inhomogeneity and margins that varied from well circumscribed to infiltrating. CONCLUSION There are two sets of MR features seen with synovial sarcoma. Small lesions of -5 cm can demonstrate a nonaggressive appearance with well circumscribed margins and homogeneous signal intensity. These tumors could be confused with benign lesions, resulting in inappropriate surgical intervention like excisional biopsies through transverse incisions. This would make future surgery more difficult. Larger lesions tend to be more heterogeneous in signal intensity.

Magnetic resonance imaging of intraosseous lipomas: a radiologic-pathologic correlation

Four patients with intraosseous lipomas were studied with magnetic resonance imaging. The imaging features and histology of each tumor were compared. Magnetic resonance imaging was very helpful in establishing a pathologic diagnosis. If a severe degree of involution was present, then the magnetic resonance findings could be ambiguous, making diagnosis more difficult.

Avascular necrosis of bone in human immunodeficiency virus infected patients

The objective of this article was to delineate the causes of avascular necrosis (AVN) in patients with human immunodeficiency virus (HIV). HIV-infected patients with pain in large joints were prospectively screened. Patients had radiographs and magnetic resonance imaging of their affected joints. Serum lipids, anticardiolipin antibody levels (IgG, IgM), and hemoglobin electrophoresis were performed on all patients who had radiographic studies. Medical records were screened for factors known to predispose for AVN. Eight patients completed the protocol, and five patients had AVN in seven joints. No common laboratory abnormality was identified in the patients with AVN. All of the patients with AVN had a history of steroid use; four of five patients having taken steroids for HIV-related diseases. The cause of AVN does not appear to be directly related to the disease, but to steroid treatment for manifestations of the disease.

Computed tomography—Guided aspiration of a ganglion cyst of the anterior cruciate ligament: A case report

This report describes the case of a ganglion cyst of the anterior cruciate ligament in a 26-year-old man who had long-standing intermittent knee pain with locking. The cyst was successfully aspirated under computed tomography guidance, with complete resolution of symptoms. A literature review is presented along with diagnostic and treatment approaches for this uncommon finding.

Internal derangement of the knee after ipsilateral femoral shaft fracture: MR imaging findings

Abstract Objective. This study uses magnetic resonance (MR) imaging to delineate the types and frequencies of injuries seen in the knee after ipsilateral femoral shaft fracture. We also compare the results of the orthopedic knee examination with the MR findings. Design and patients. MR imaging of the ipsilateral knee was performed on 34 patients with closed femoral shaft fractures. Indications for knee MR imaging included knee pain at the time of fracture, soft tissue swelling or an effusion of the knee, or a positive knee examination under anesthesia. The patients had a mean age of 27 years and all were stabilized with intramedullary nails. Imaging was performed a mean time of 2.5 days after surgery. All patients had knee examinations done under anesthesia, and the MR results were compiled and compared with the clinical examinations. Results. Ninety-seven percent of patients demonstrated knee effusions. Twenty-seven percent of patients demonstrated meniscal tears, with the posterior horn of the medial meniscus most frequently torn. The medial collateral ligament was the most frequent site of ligamentous injury (38%) followed by the posterior cruciate ligament (21%). Fifty percent of patients had injuries of the extensor mechanism. Bone bruises were noted in 32% of patients. Articular cartilage injuries were confined to the patella in four cases. One occult tibial plateau fracture and one meniscocapsular separation were seen. Conclusions. There is a common incidence of both ligamentous and meniscal injury to the knee after ipsilateral femoral shaft fracture. MR imaging can be useful in assessing the extent of injury, and may reveal findings unsuspected after clinical examination of the knee.

Osteogenesis imperfecta with joint contractures: Bruck syndrome

Abstract We describe an Egyptian boy with osteogenesis imperfecta who was born with thumb contractures and bilateral antecubital pterygia. He was seen at 16 months of age with femur and tibial fractures, thoracic vertebral compression fractures, scoliosis and Wormian bones. The findings are consistent with a diagnosis of Bruck syndrome.

A Case Report of Intracortical Hemangioma A Forgotten Intracortical Lesion

The differential diagnosis for lytic intracortical lesions consists primarily of osteoid osteoma and Brodies abscess. A third, less-well-known lesion is the intracortical hemangioma. It has an identical appearance to the two aforementioned lesions on bone scan and radiographs. This case report will describe the magnetic resonance imaging appearance of intracortical hemangioma and how it might be differentiated from osteoid osteoma and Brodies abscess.

Cortical chondroblastoma: report of a case and literature review of this lesion reported in unusual locations.

Chondroblastoma is a rare benign tumor occurring in adolescence and young adulthood, almost always involving the epiphysis of long bones. A 24-year-old man presented with a discrete soft-tissue lesion penetrating the cortex of the right distal femoral metadiaphyseal region. Biopsy revealed a chondroblastoma, and the patient subsequently underwent a total curettage of the lesion with cancellous bone graft from the iliac crest.

Nuchal Fibroma of the Shoulder Involving Skeletal Muscle: A Radiographic and Clinicopathological Study. A Case Report*

Nuchal fibromas are rare superficial lesions involving the skin and subcutaneous tissue of the neck. Clinically and radiographically, they may resemble more invasive lesions such as dermatofibrosarcoma protuberans and fibromatosis (extra-abdominal desmoid tumor), which usually involve the skin and the subcutaneous tissue, or they may resemble synovial sarcoma, which involves the deep tissue. We report the case of a patient who had a nuchal fibroma that involved skeletal muscle and peripheral nerves. An athletic fifteen-year-old boy was noted to have a large painless mass over the left shoulder during a routine physical examination. The mass had been present for at least one year, and the patient had no history of trauma. Additional examination revealed a poorly defined, rubbery mass, measuring fifteen by ten centimeters, that displaced the scapula posteriorly and inferiorily. There was no evidence of scoliosis and no history of neuromuscular disease. The remainder of the history and physical examination was unremarkable. Standard radiographs of the shoulder and scapula did not reveal any osseous involvement but confirmed the presence of a soft-tissue mass (Fig. 1). Fig. 1 Anteroposterior radiograph showing the soft-tissue mass (arrowheads) between the left scapula and the rib cage. Magnetic resonance imaging of the shoulder and scapula revealed a septated mass along the posterolateral aspect of the left part of the thorax; the mass …

Bilateral diskoid medial menisci diagnosed by magnetic resonance imaging: a case report.

A diskoid medial meniscus is a rare finding occurring in approximately 0.3% of the general population. Bilateral medial diskoid menisci are even less common, with only three other cases appearing in the literature. This may be the first reported case of bilateral medial diskoid menisci diagnosed by magnetic resonance imaging and verified at arthroscopy.