Malignant Bone And Soft Tissue Tumors Flashcards
Four aspects of a lesion to be examined
CPOZ
- Cortical destruction,
- periostitis,
- orientation or axis of the lesion,
- zone of transition
Aspect of lesion that is accurate in detecting malignancy 90% of the time
Zone of transition
Periosteal reaction of most benign type
Callus formation
Slow-growing benign tumor will cause what appearance of periostitis because it is a low grade chronic irritation that gives the periosteum time to lay down thick new bone and remodel into more normal cortex
Thick, wavy, uniform or dense periostitis
Appearance of malignant periostitis
Lamellated (onion-skinned) of amorphous or even sunburst-like
The only way a benign periostitis can occur in a malignant lesion is if there is a
Concomitant fracture or infection
Zone of transition is defined as
Border of the lesion with the normal bone
Zone of transition is narrowed, if it appears
Well-defined
Zone of transition is wide, if it appears
Imperceptable and cannot be clearly drawn at all
Permeative lesions are often seen in what malignant tumors (3)
MPE
- Multiple myeloma,
- primary lymphoma of bone (reticulum cell sarcoma) and
- Ewing sarcoma
Permeative lesions can also be seen in what benign lesions (2)
Infection and EG
Childhood primary malignant tumors of the bone (2)
Osteosarcoma and Ewing sarcoma
Malignant tumors after age 40 (3)
MMC
- Metastatic disease,
- myeloma,
- chondrosarcoma
Malignant bone tumors in ages 30-40 (4)
GPMF
- GCT,
- parosteal sarcoma,
- malignant fibrous histiocytoma,
- first degree lymphoma of bone
Almost all malignant tumors in MRI will present as
Low signal in T1, high signal on T2
Most common malignant primary bone tumor
Osteosarcoma
Osteosarcoma in the 6th decade are probably because of (2)
Secondary osteosarcoma in Paget disease and because of prior radiation
Lytic form of osteosarcoma
Telangiectatic osteosarcoma
General appearance of osteosarcoma in MR
Large soft tissue component with heterogeneous high and low signal intensities on both T1 and T2
Form of osteosarcoma that originates from the periosteum of bone and grows outside the bone
Parosteal sarcoma
Form of osteosarcoma that often wraps around the diaphysis without breaking through the cortex at all
Parosteal osteosarcoma
Treatment of parosteal osteosarcoma
Shaving the tumor off the bone or wide bloc excision
Parosteal osteosarcoma are more common in the young or older
Older age group
Characteristic of parosteal osteosarcoma that if present, will be considered as aggressive as the central osteosarcoma
If it violates the cortex of adjacent bone