- Osteoid Osteoma: CT Findings
-Nidus surrounded by variable amount of sclerosis
-Nidus may enhance on contrast enhanced CT
-Periosteal reaction common
-CT can be used as a guide for RF ablation of the lesion - Osteoid Osteoma: Facts
-Age 5-25 yrs is 90% of cases
-M:F is 2-1
-Local pain usually worse at night
-Common locations include proxiaml femur, hands and feet
-Classic finding is nidus which is 1.5 cm or less - Extraosseous Myeloma: Sites of Involvement
- Spleen
- Liver
- Kidneys
- Small bowel
- Lymph nodes
- Pulmonary nodules
- Pleural implants "Extraosseous myeloma can affect virtually any organ, and the imaging findings of extraosseous myeloma are nonspecific and can mimic other disorders." Imaging of Extraosseous Myeloma: CT, PET/CT, and MRI Features
Hall MN et al.
AJR 2010; 195:1057-1065 "The presence of radiologically detectable extraosseous myeloma is associated with a poor prognosis and thus is an important factor in the initial workup and follow-up evaluation" Imaging of Extraosseous Myeloma: CT, PET/CT, and MRI Features
Hall MN et al.
AJR 2010; 195:1057-1065 "Extraosseous myeloma may affect any organ and can mimic other malignancies. The objective of this article is to describe the clinical relevance of extraosseous myeloma and to present the diverse imaging findings of extraosseous myeloma." Imaging of Extraosseous Myeloma: CT, PET/CT, and MRI Features
Hall MN et al.
AJR 2010; 195:1057-1065 - Secondary Osteosarcoma: facts
- Tumor arises in preexisting condition in bone like;
- Pagets disease
- Prior radiated bone
- Dedifferentiated chondrosarcoma
- Bone infarct - Osteosarcoma: Differential Dx includes
- Ewing sarcoma
- Chondrosarcoma (clear cell)
- Fibrous dysplasia
- Metastases
- Aggressive osteomyelitis - Osteosarcoma: Facts
- Most common primary bone tumor in children and young adults
- Occurs in metaphysis of long bones in 80% of cases 55% of cases occur around the knee
- 20% of cases occur in flat bones and spine
- Aggressive periosteal reaction with sunburst appearance - Classic Osteosarcoma: facts
- Origin in metaphysis
- Most common in long bones (70-80%) and especially around the knee
- Usually has aggressive periosteal reaction with new bone formation
- CT shows osteoid component of the tumor very nicely - Osteosarcoma: Facts
- Most common primary bone tumor in childhood and young adulthood
- 2nd most common primary bone tumor
- High grade intramedullary osteosarcoma makes up 75% of cases - Clinical presentation
- Lower back pain
- Sensory loss
- Gait disturbances
- Bladder and bowel dysfunction - Extradural Sacral Myxopapillary Ependymoma: Factoids
- Patients in 3rd or 4th decade
- Slow, insidious onset - Differential Dx
- Chordoma-age 60-70
- Metastases-usually >40
- Myeloma or plasmacytoma-age >40
- Giant cell tumor
- Aneurysmal bone cyst-age 10-20
- Neurogenic tumor - Extradural Sacral Myxopapillary Ependymoma
- Myxopapillary Ependymoma almost always occurs in the region corresponding to the filum terminale or cauda equina
- May be extradural in the presacral space or within the sacrum
- Although primarily suggesting a bone tumor on imaging a presacral mass is not uncommon
- These are slow growing tumors with local recurrence common - Extradural Sacral Myxopapillary Ependymoma
- Ependymomas represent 4-6% of primary CNS lesions
- Ependymomas make up 63% of intraparenchymal lesions of the spinal cord
- Myxopapillary ependymoma account for 25% of all ependymomas (most common type) - “Whole body MDCT leads to a significantly lower detection rate and staging in patients with multiple myeloma.” Whole Body MRI Versus Whole Body MDCT for Staging of Multiple Myeloma
Baur-Melnyk A et al.
AJR 2008; 190:1097-1104
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