Malignant Bone And Soft Tissue Tumors Flashcards
Four aspects of a lesion to be examined
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
Multiple myeloma, primary lymphoma of bone (reticulum cell sarcoma) and Ewinh sarcoma
Permeative lesions can also be seen in what benign lesions
Infection and EG
Childhood primary malignant tumors of the bone
Osteosarcoma and Ewing sarcoma
Malignant tumors after age 40
Metastatic disease, myeloma, chondrosarcoma
Malignant bone tumors in ages 30-40
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
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
Treatment of central osteosarcoma
Radical excision
Common location from which parosteal osteosarcoma arise
Posterior femur, near the knee
An avulsion injury that is totally benign but can appear somewhat aggressive and can mimic an early parosteal osteosarcoma
Cortical desmoid
Myositis ossificans may be confused with what malignant tumor
Parosteal osteosarcoma
Permeative lesion in the diaphysis of a long bone in a child
Ewing sarcoma
Area of predilection of Ewing sarcoma
40% in diaphysis, the remainder being metaphyseal, diametaphyseal and in flat bones
What benign lesion is usually incomparable in terms of appearance with chondrosarcoma
Enchondroma
Chondrosarcoma may be considered, if a lesion that looks like enchondroma has what other clinical features
Painful, shows periostitis and cortical destruction
If a soft tissue mass or edema is present in an enchondroma-like lesion, what should be considered, enchondroma or chondrosarcoma?
Chondrosarcoma
Appearance of chondrosarcoma in radiographs
Snowflake or popcorn like amorphous calcification
About how many percent of gcts are malignant
15%
Lytic malignant tumors that do not produce osteoid or chondroid matrix
Malignant fibrous histiocytoma or fibrosarcoma
One of the few malignant tumors that can, on occassion have a bony sequestrum
MFH
A half-grade MFH
Desmoid tumor, aka desmoplastjc fibroma or aggressive fibromatosis
These lesions commonly arise in the soft tissue, when in bone, they are lytic but are usually fairly well defined because of their slow growth. Often have benign periostitis present that has thick spicules or spikes, have multilocular appearance with thick bony septa. Do not metastasize by can exhibit inexorable tumor extension into surrounding soft tissues
Desmoid tumor
Neoplasm that has the same appearance as Ewing sarcoma, except that it occurs in older age group
Primary lymphoma of bone or reticulum cell sarcoma
Only malignant tumor that can involve a large amount of bone while being asymptomatic
Primary lymphoma
Multiple sclerotic foci in a man are most likely from
Prostatic metastases
In a woman with sclerotic foci, it is most likely from
Breast metastases
Only primary tumor that never presents with blastic metastatic disease is
Renal cell carcinoma
Classic differential diagnosis for expansile, lytic metastasis is
Renal cell or thyroid carcinoma
Myeloma frequently involves the
Calvarium
One of the malignant bone lesions that is not characteristically hot on radionuclide bone scan, therefore radiologic bone surveys are performed instead
Myeloma
Pathognomonic feature of synovial osteochondromatosis
Presence of calcific loose bodies
Non ossified loose bodies in synovial osteochondromatosis is undistinguishable in what other condition
Pigmented villonodular synovitis
Typical appearance of pigmented villonodular synovitis in MRI
Low signal intensity of synovium on both T1 and T2 that is typical for hemosiderim deposits
Tumors now labelled as pleomorphic undifferentiated sarcomas
MFH and liposarcoma
Cortical holes occur almost exclusively in
Radiation and soft tissue hemangioma
Commonly associated finding of hemangioma
Presence of phleboliths
Synovial sarcomas are often seen where
Adjacent to joints, very rarely in a joint
Tumors that are typically homogeneously bright on T2 to that extent that they can be mistaken for a fluid collection
Synovial sarcomas and neural tumors
Benign joint lesion that occurs from metaplasia of synovium and leads to multiple calcific loose bodies in a joint
Synovial osteochondromatosis
Benign synovial soft tissue process that causes joint swelling and pain and occassionally, periarticular erosions. It virtually never has calcifications
Pigmented villonodular synovitis
Condition that may mimic PVNS in which there is chronic bleeding in joint
Hemosiderotic arthritis
True permeative pattern of round cell lesions occur in what part of bone
Intramedullary or endosteal part
Pseudopermeative pattern of bone lesion is seen in what part of bone
Cortical
Can present as soft tissue mass, appears homogeneously bright on T2 and often septated, seen around the joint of knee
Atypical synovial cysts such as Baker cysts
