Biomedical subjects
Publications and source records attributed to Murali Sundaram.
OBJECTIVE: The objective of this article is to define the imaging characteristics of spindle cell lipoma on MRI and CT. CONCLUSION: The diagnosis of spindle cell lipoma should be suggested when a well-defined complex fatty mass is found in the subcutis of a middle-aged man, especially if the mass is localized to the posterior neck. Intense enhancement of the nonadipose component further supports this diagnosis.
Explore the source record for details and available documents.
Accurate diagnosis of posterior shoulder dislocation requires a high index of suspicion in shoulder trauma patients and proper radiographic evaluation. This case highlights the importance of obtaining axillary views in shoulder trauma cases.
Explore the source record for details and available documents.
Sarcomas--like leukemias, which are also mesodermal malignancies--carry biological significance disproportionate to their clinical frequency. Identification of mutations and translocations associated with these tumors has illuminated aberrant signaling pathways that cause these diseases, determine their behavior, and are therapeutic targets. Activated receptor-associated tyrosine kinase c-kit, mutated in most gastrointestinal stromal tumors, has proven a clinically effective target for enzyme inhibition. A translocation involving a single gene family, consisting of EWS and related genes, has been identified in five different sarcomas, and its chimeric protein products could prove similarly amenable to inhibitors. Resolution of the histopathological complexity is being aided by data from molecular and chromosomal characterization. Improvements in imaging, definition of prognostic factors, and surgical and radiotherapeutic treatment have resulted in improved local control. Continued progress will depend on further adapting the rapidly evolving technologies of genomics and proteomics. It will also depend upon accurate histopathological diagnosis based on validated reagents and consistent methodologies applied to adequate tissue samples derived from patients with complete clinical data. Finally, multicenter, coordinated trials, such as those that occurred with assessment of imatinib mesylate in metastatic gastrointestinal stromal tumors, will assure the most rapid reductions in morbidity and mortality.
OBJECTIVE: To determine the age distribution, gender, incidence, and imaging findings of vertebral chondroblastoma, and to compare our series with findings from case reports in the world literature. DESIGN AND PATIENTS: Case records and imaging findings of nine histologically documented vertebral chondroblastomas were retrospectively reviewed for patient age, gender, vertebral column location and level, morphology, matrix, edema, soft tissue mass, spinal canal invasion, and metastases. Our findings were compared with a total of nine patients identified from previous publications in the world literature. The histologic findings in our cases was re-reviewed for diagnosis and specifically for features of calcification and secondary aneurysmal bone cyst (ABC). Clinical follow-up was requested from referring institutions. RESULTS: Nine of 856 chondroblastomas arose in vertebrae (incidence 1.4%; thoracic 5, lumbar 1, cervical 2, sacral 1). There were six males and three females ranging in age from 5 to 41 years (mean 28 years). Satisfactory imaging from seven patients revealed the tumor to arise from the posterior elements in four and the body in three. All tumors were expansive, six of seven were aggressive, and the spinal canal was significantly narrowed by bone or soft tissue mass in six. In one patient canal invasion was minimal. Calcification was pronounced in two and subtle in four. The sole nonaggressive-appearing tumor was heavily mineralized. Bony edema and secondary ABC were not seen on MR imaging. None of the cases had microscopic features of significant secondary ABC. Calcification, and specifically "chicken wire" calcification, was identified in two patients. Pulmonary metastases occurred in none. CONCLUSIONS: Vertebral chondroblastoma is a rare neoplasm that presents later in life than its appendicular counterpart. On imaging it is aggressive in appearance with bone destruction, soft tissue mass, and spinal canal invasion. The lesions contain variable amounts of mineral. Secondary aneurysmal cyst bone formation was not a feature in our study group.
Oncogenic osteomalacia is a rare paraneoplastic syndrome caused by bone and soft tissue tumors. The characteristic clinical, metabolic, and imaging findings are reviewed, as is the radiologist's role in evaluation and diagnosis. New insight into the pathophysiology of oncogenic osteomalacia is also presented.
Angiosarcoma is an extremely rare bone tumor. The authors report two cases of patients with angiosarcoma that developed adjacent to a stainless steel plate used for fixation of a femur fracture. In both patients, the interval between fracture treatment and the development of the neoplasm was more than 40 years. A review of the literature found 36 previously reported cases of malignancy arising adjacent to an orthopaedic implant. Despite any evidence directly linking these implants to the development of cancer, continued vigilance is warranted.
Explore the source record for details and available documents.
Glenolabral articular disruption lesions are an unusual source of anterior shoulder instability and pain. They may be difficult to diagnose clinically and often require surgical repair. Magnetic resonance arthrography is superior to other imaging techniques, including conventional MRI, in the evaluation of shoulder instability.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Arthroscopic abrasion arthroplasty, subchondral drilling, and microfracture continue to be performed with some frequency in younger patients with focal chondral defects and occasionally for patients with moderate degenerative knee arthritis. The plain radiographic appearance after those procedures may mimic avascular necrosis, but MRI is a sensitive method used to exclude the diagnosis of avascular necrosis and evaluate the extent to which fibrocartilaginous repair tissue has formed. When combined with an appropriate clinical history, dedicated articular cartilage imaging sequences improve the sensitivity and specificity that MRI provides in these patients with chondral knee injuries.
Intraosseous lipomas are uncommon lesions of bone most often diagnosed incidentally. They typically manifest a classic radiographic appearance, but CT or MRI may be useful in diagnosing lesions that are atypical or incompletely defined radiographically and avoid an unnecessary biopsy.
Over the past decade, magnetic resonance (MR) imaging has been established as the most widely used examination for the detection of a suspected soft tissue mass and often for depiction of the extent and the characterization of the mass. Sensitivity of the examination for the detection of soft tissue masses is high but specificity is limited. With experience accrued over the past decade, radiologists are increasingly able to predict the histology of lesions based on MR imaging criteria. However, because of the overlap of morphologic features of benign and malignant soft tissue masses, a benign-appearing mass should not be considered benign unless the tumor can be specifically named and its histology predicted by well-established MR imaging features. When a mass is not thought to be an overt sarcoma and there is uncertainty as to whether it is benign or malignant, the tumor should be characterized as indeterminate and approached as a sarcoma until proven otherwise. This article reviews MR imaging in diagnosing and staging soft tissue masses and briefly discusses the radiologistÕs approach to percutaneous biopsy of indeterminate soft tissue masses.
Up to 11% of chondrosarcomas may undergo regional anaplastic change, resulting in a high-grade noncartilaginous sarcoma arising within a typically low-grade chondrosarcoma. Known as dedifferentiated chondrosarcomas, these tumors are highly malignant with a very poor prognosis. The most important factor affecting survival is an accurate preoperative diagnosis. Therefore, the ability to predict the possibility of dedifferentiation in a malignant cartilage tumor on the basis of imaging findings is critical to ensure adequate tumor sampling at the time of biopsy. Imaging findings at radiography, computed tomography (CT), and magnetic resonance (MR) imaging in 174 patients with dedifferentiated chondrosarcoma were reviewed to determine whether there are radiologic features that can help predict dedifferentiation. On approximately one-third of the radiographs, one-third of the MR images, and one-half of the CT scans, the tumors demonstrated bimorphic features (ie, distinctly different tumor features juxtaposed within the lesion), most frequently a dominant lytic area adjacent to a mineralized tumor at radiography and a large, unmineralized soft-tissue mass associated with an intraosseous chondroid-containing tumor at CT and MR imaging. In the initial evaluation of patients with a primary bone tumor, thorough evaluation of the radiologic features of the entire tumor is critical.