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78 Cards in this Set

  • Front
  • Back
Fibrous Dysplasia
Enchonroma and Eosinophilic Granuloma
Giant Cell Tumor
Nonossifying Fibroma
Metastatic Dz and Myeloma
Aneurysmal Bone Cyst
Solitary Bone Cyst
Hyperparathyroidism (Brown Tumors)
Chondromyxoid Fibroma
Fibrous Dysplasia can look like?
Fibrous Dysplasia...mono or polyostotic? Locations of prediliction?
Can be monostotic or polyostotic. Likes the pelvis, prox femur, ribs and skull.
When Fibrous Dysplasia is in pelvis where else is it usually?
Ipsilateral proximal femur is almost always involved. If prox femur is involved though you don't always see pelvic involv.
Fibrous Dysplasia appearance when in the ribs.
It is often expansile, lytic appearing in posterior ribs. Ant ribs it appears sclerotic.
What is the classic description of fibrous dysplasia appearance?
ground glass or smoky matrix...however this can be misleading as fd can also look purely lytic and later become hazy as it calcifies...then look sclerotic. Also other lytic appearing lesions can have a ground glass appearance.
When a lesion is encountered in the tibia that resembles fd this should be considered. Malignant tumor. Resembles fibrous dysplasia. Seen exclusively in tibia and jaw. Rare.
McCune Albright Synd. what is it?
polyostotic fibrous dysplasia with cafe-au-lait spots, precocious puberty.
What is peculiar about the lesion location in Mcune Albright Sx.?
Usually unilateral..also seen in simple polyostotic fd but this characteristic is not used diagnostically.
presence of multiple fibrous dysplasia lesions in the jaw is called?
What is the Brant and Helms discriminator for fibrous displasia?
No periostitis.
Two benign lesions that occur in any bone formed from cartilage?
Enchondroma and Eosinophilic Granuloma.
What to enchondroma and eosinophilic granuloma invariably contain?
(with one exception)
calcified chondroid matrix, except when in the phalanges
What is the most common benign cystic lesion in the phalanges?
Often it is difficult to differentiate what from enchondroma?
bone infarct
What is the typical appearance of a bone infarct and how does this contrast with enchondroma?
Well-defined densely sclerotic serpiginous bordered lesion where an enchondroma does not. Enchondroma often has endosteal scalloping whereas a bone infarct will not....these are not fool proof but help.
It is difficult if not impossible to differentiate an enchondroma from what?
chondrosarcoma. Pain and periositis serves as a discriminator. Histology isn't much help.
What is Ollier dz?
Multiple enchondromas.
A lytic lesion in the phalanges is most commonly what?
Multiple enchondroma's associated with st hemangiomas is called?
Maffuci syndrome.
Does Ollier dz and Mafucci syndrome have increased incidence of malignant degeneration compared with standard enchondroma?
Ollier's does not. Mafucci's does.
What are the descriminators for enchondromas given by Brant and Helms?
1. Must have calcification (except in phalanges)
2. No periostitis or pain.
Eosinophilic Granuloma is a form of what disease and includes what others?
a form of histiocytosis X, the other forms being Leterrer-Siwe dz and hand-Schuller-Christian dz. Thought to be different phases of same dz.
Appearance of EG?
Can have many appearances...lytic or sclerotic, well or ill-defined, might or might not have sclerotic border, might or might not have periosteal response.
What scary thing can EG look like?
Ewing's Sarc as it can present as a permeative lesion.
Discriminating factor for EG is...
Age only...less than 30 and usually less than 20 years of age.
Is EG mono or polyostotic?
usually mono but can be poly.
Giant Cell common are these?
What is their etiology?
Are Giant Cell tumors malignant or benign?
mostly benign...even when "malignant" they met to lungs rarely. 15% "malignant". They have a tendancy to recur even after resection.
Treatment for Giant Cell tumor?
Surgeons curretage and pack them and consider them benign even if they recur. Can recur a second or third time...then start saying "malignant". Histology is useless.
Four criteria that must be met to diagnose a giant cell tumor...
1. onlly in patients with closed physis
2. Lesion must be epiphyseal and abut the articular surface. Can also be metaphyseal but the above criteria must be met unless it is in a flat bone.
3. eccentrically located...difficult when large. This is just a classic rule.
4. Must have sharply defined zone of transition that is not sclerotic. Exception is in flat bones.
Where are two locations that giant cell tumors occur often that the rules dont apply? (2)
Pelvis and calcaneus.
What is the most common bone lesion encountered by radiologists and what is the population it is seen in most?
Non-Ossifying Fibroma. 20% of children. Regress and seen rarely after 30.
Another name for NOF (smaller lesion)?
Fibrous cortical defect if <2cm
Radiographic location and description of NOF?
usually metaphysis of long bone, emenating from cortex (eccentric), thin sclerotic border...a fairly general description that could be any FEGNOMASHIC lesion but fits 75% of NOF's.
When NOF's regress and "heal" what study can be false positive?
they are hot on NM study.
Where is most common site for NOF?
Knee, but can occur in any long bone.
What are the Brant and Helms discriminators for Non Ossifying Fibroma's?
1. <30
2. No periostitis or pain.
3. Cortically based.
Are osteoblastomas common or rare?
Osteoblastomas have two appearances...
1. Look like large osteoid osteoma's and are often called giant osteoid osteoma's. (these are sclerotic lesions not resembling bubbly lytic lesions)
2. They look like ABC's being expansile with soap bubble appearance.
If an ABC is being considered in diagnosis what else should be?
What do osteoblastoma's typically look like and where to they typically appear?
posterior elements of the vertebral bodies. Half have speckled calcifications.
What is a classic definition for an expansile lytic lesion of the posterior elements of the spine?
osteoblastoma, abc, tuberculosis
What is the discriminator for osteoblastoma?
mentioned when ABC is mentioned esp in the posterior elements of the spine.
Osteoblastomas are so uncommon that...
you might see one in your career. They are included to complete the mnemonic...
In a pt over 40 any lytic lesion should have this in the differetnial? CAN appear benign radiographically...although most do not.
How does myeloma usually present?
diffuse permeative process in the skeleton...however it can present as a solitary lesion.
what is the term for a myeloma lesion and what to they look like?
bubbly lytic lesion...plasmacytoma.
In general it is safe to lump all metestatic dz in this age category...
Over 40...almost all are over this age. If less than 40 don't consider.
In general lytic expansile bone mets tends to come from what primaries?
thyroid and renal tumors
What is the bone met that is the only one that is always lytic?
renal cell carcinoma
Virtually any metastatic process can present how?
As a benign appearing lytic lesion...therefore it is useless to try to characterize what type of met it is.
Where is common site for plasmacytoma?
Aneurysmal bone cysts are the only lesion that is named for...
radiographic appearance...virtually always expansile or aneurysmal.
Pt population of people with ABC's
usually under 30 crowd, although occasionally seen in older patients.
What is a finding of ABC's on MR or CT?
fluid levels...non-specific but helps.
Two types ABC's
1. Primary - no known cause (controversial like Giant Cell Tumors in this way)
2. Secondary - occur with other lesions such as Giant Cell Tumors, osteosarcs, and in conjunction with almost any other lesion or from trauma.
Where do ABC's commonly occur?
Can occur anywhere but common in posterior elements of spine like osteoblastoma.
Discriminators for ABC's
1. must be expansile
2. younger than 30
Other names for Solitary bone cysts...
Unicameral bone cyst. simple bone cyst
What are the discriminators for bone cyst
1. must be central always (only lesion in FEGNOMASHIC that has this criteria)
2. less than 30
3. No periostitis
What is a characteristic about bone cyst location compared to other lesions in FEGNOMASHIC?
One of the few that doesn't occur around the knee
Where to bone cysts usually occur?
2/3 to 3/4 occur in prox humerus and femur
Fallen fragment sign is pathognomonic for?
bone cyst.
What appearance do Brown tumors have?
almost any, from purely lytic to sclerotic.
If a brown tumor is to be considered in DDx what else must be looked for?
Other evidence of HPT.
What finding is pathognomonic for HPT?
Subperiosteal bone resorption. This should be searched for in the phalanges and is most commonly seen in radial aspect of middle phalanges)
what does subperiosteal bone resorption look like?
narrowing middle phalanges.
What other sites have subperiosteal bone resorption in HPT?
distal clavicles, medial prox tibia, si joints.
Chondroblastomas are rare/common?
Chondroblastomas are easy/hard to deal with radiologically? Why?
easy...only seen in the epiphysis and in patients < 30
How many chondroblastomas calcify?
Is calcification helpful for dx chondroblastoma?
yes, as long as it's not infection or EG which can occur in the epiphysis. Absence doesn't help.
Classic differential for epiphysial lytic lesion in a pt under 30.
1. infection
2. chondroblastoma
3. giant cell tumor
This encompasses 98% of all epiphyseal lesions in this age group.
Chondromyxoid rare/common
rare, once in a lifetime.
Chondromyxoid fibromas resemble what?
Discriminators for Chondromyxoid fibromas.
1. mention when NOF mentioned
2. no calcified matrix