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Musculoskeletal
Bone Tumors
Mohamed Zaitoun
Assistant Lecturer-Diagnostic Radiology Department , Zagazig University Hospitals
EgyptFINR (Fellowship of Interventional
Neuroradiology)[email protected]
Knowing as much as possible about your enemy precedes successful battle
and learning about the disease process precedes successful management
Introduction-Benign Criteria of Bone Tumors :1-Well defined margin2-Sclerotic rim3-Expanding lesion4-No periosteal reaction5-No extraosseous soft tissue component6-Narrow zone of transition
-Malignant Criteria of Bone Tumors :1-ill defined margins2-Cortical destruction3-Periosteal reaction4-Extraosseous extension5-Intra-articular invasion6-Neurovascular bundle affection7-Wide zone of transition
-Location Within Anatomic Regions :a) Epiphysis :1-Chondroblastoma2-Infection3-Geode4-GCTb) Metaphyseal :-Lesions of different causes : neoplastic ,
inflammatory and metabolic
c) Epiphyseal / Metaphyseal :-GCTd) Diaphysis :-After the 4th decade of life , most solitary
diaphyseal bone lesions involve the bone marrow
Bone Tumors(i) Bone Forming Tumors(ii) Cartilage Forming Tumors(iii) Fibrous Lesions(iv) Bone Marrow Tumors(v) Other Bone Tumors(vi) Metastases(vii) Miscellaneous
(i) Bone Forming Tumors :a) Benign :1-Bone Island2-Osteoblastoma3-Osteoma4-Osteod Osteomab) Malignant :-Osteosarcoma
a) Benign :1-Bone Island2-Osteoblastoma3-Osteoma4-Osteod Osteoma
1-Bone Island : (Enostosis)a) Incidenceb) Locationc) Associations d) Radiographic Features
a) Incidence :-Common and benign bone lesions that are
usually seen as an incidental findings-They constitute a small focus of compact
bone within cancellous bone-N.B. : All the tumors are osteolytic except :1-Bone Island2-Osteoma
b) Location :Bone islands may occur anywhere in the
skeleton although there is some predilection for pelvis , long bones , spine and ribs
c) Associations :-Osteopoikilosis : multiple bone islands
Osteopoikilosis
Osteopoikilosis
d) Radiographic Features :-They are commonly seen as small round or oval
foci of dense bone within the medullary space-The appearance of radiating spicules at the
margins that blend with the surrounding trabeculae is pathognomonic
-The size of a bone island is typically less than 1cm , although large ones may occur particularly in the pelvis and are termed giant bone islands
-MRI : Low signal intensity on all sequences
2-Osteoblastoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Rare benign primary bone tumor -Young age-It is histologically similar to an osteoid
osteoma except that it is much large
b) Location :-Transverse process of vertebrae-Sacrum
c) Radiographic Features :-Lesions are predominantly lytic > 2 cm with
a rim of reactive sclerosis-Expansile well-circumscribed lesion similar
to ABC-Variable central calcification and matrix
3-Osteoma :a) Location b) Radiographic Features
a) Location :-Skull & PNS-When multiple consider Gardner’s
syndrome
b) Radiographic Features :-Osteoma appears as very radiodense
lesions
4-Osteod Osteoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Benign bone tumor that typically occur in children
(particularly adolescents)-They have characteristic appearances and
classically cause night pain that is relieved by the use of Aspirin
b) Location :-Long bones of the limbs , femur (especially neck)
and mid-tibia (close to the cortex)-Hand & Feet (navicular bone)
c) Radiographic Features :-Radiolucent nidus <2 cm in diameter (may
contain bone matrix)-Nidus surrounded by sclerosis
b) Malignant :Osteosarcomaa) Incidenceb) Locationc) Types d) Radiographic Features
a) Incidence :-Malignant bone forming tumor and the
second most common primary bone tumor after multiple myeloma
b) Location : eccentric-Around knee (Femur & Tibia)-Humerus (less common)
c) Types :1-Primary osseous OSA (95%) 2-Juxtacortical OSA 3-Secondary OSA : to Paget’s disease
d) Radiographic Features :-Malignant criteria-Aggressive periosteal reaction :1-Sunburst type2-Codman triangle
With pathological fracture
With Paget’s Disease
Sunburst
Sunburst
Codman triangle
(ii) Cartilage Forming Tumors :a) Benign :1-Chondroblastoma2-Enchondroma3-Enchondromatosis4-Maffucci’s Syndrome5-Osteochondroma (Exostosis)6-Hereditary Multiple Exostoses7-Chondromyxoid Fibromab) Malignant :-Chondrosarcoma
a) Benign :1-Chondroblastoma2-Enchondroma3-Enchondromatosis4-Maffucci’s Syndrome5-Osteochondroma (Exostosis)6-Hereditary Multiple Exostoses7-Chondromyxoid Fibroma
1-Chondroblastoma :a) Locationb) Radiographic Features
a) Location : Epiphyseal lesion-Chondroblastoma most frequently arise in
the epiphyses of long bones with 70% occurring in the humerus (most frequent) , femur and tibia
b) Radiographic Features :-Chondroblastoma is seen as well defined
lytic lesion with either smooth or lobulated margins with a thin sclerotic rim
2-Enchondroma :a) Associationsb) Locationc) Radiographic Features
a) Associations :1-Ollier disease2-Maffucci syndrome
b) Location :-Small tubular bones of the hands and feet :
50 %, more in the proximal phalanges
c) Radiographic Features :-Benign Features-Lytic lesion in bones of the hand or foot ,
expansile-Chondroid calcifications : rings and arcs
pattern (O and C)
3-Enchondromatosis : (Ollier disease)-Is multiple enchondromas-Multiple radiolucent expansile masses in
hand and feet-Hand and foot deformity-Tendency for unilaterality
4-Maffucci’s Syndrome :-Enchondromatosis and multiple soft tissue
hemangiomas-Unilateral involvement of hands and feet-Malignant transformation is much more
common than in Ollier disease
5-Osteochondroma (Osteocartilaginous Exostosis) :
a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Most common benign -Young age
b) Location :-Knee-Humerus
c) Radiographic Features :1-Plain Radiography & CT : 5C-Continuous with parent bone-Uninterrupted cortex-Continuous medullary bone-Calcification in the chondrous portion of cap
, may be cauliflower-like-Metaphyseal location (cartilaginous origin)-Lesion grows away from joint
2-MRI :-MRI demonstrates cortical and medullary continuity
between the osteochondroma and the parent bone-The cartilage cap of osteochondroma appears the same
as cartilage elsewhere with intermediate to low signal on T1 and high signal on T2
-A cartilage cap of over 1.5 cm in thickness is suspicious for malignant degeneration
-With intravenous gadolinium administration , enhancement of benign lesions is normally seen in the tissue that covers the cartilaginous cap which is fibrovascular in nature , however the cartilaginous cap itself should not enhance
6-Hereditary Multiple Exostoses :-Multiple osteochondromas
7-Chondromyxoid Fibroma :-Eccentric position in the metaphysis of the long
bones (50 % around the knee)-Often seen as a lobulated eccentric radiolucent
lesion-Long axis parallel to long axis of long bone-No periosteal reaction (unless a complicating
fracture present)-Geographic bone destruction : almost 100%-Well defined sclerotic margin
b) Malignant :-Chondrosarcomaa) Incidenceb) Locationc) Typesd) Radiographic Features
a) Incidence :-Malignant cartilaginous tumors that account for
20-27% of all primary malignant bone tumors-Typical presentation is in the 4th and 5th decades
b) Location :-Long bones : 45%, femur-Flat bone (Ribs, clavicle & scapula)
c) Types :1-Primary2-Secondary :-Enchondroma-Osteochondroma
d) Radiographic Features :-Malignant criteria (Lytic lesion) + Calcifications
(rings and arcs calcification or popcorn calcification)
Chondrosarcoma , sphenoid wing
(iii) Fibrous Lesions :a) Benign :1-Fibrous Cortical Defect (FCD) & Non-Ossifying Fibroma
(NOF)2-Fibrous Dysplasia3-Ossifying Fibroma4-Desmoplastic Fibroma5-LipoSclerosing MyxoFibrous Tumor (LSMFT)b) Malignant :1-Malignant Fibrous Histiocytoma2-Fibrosarcoma
a) Benign :1-Fibrous Cortical Defect (FCD) & Non-
Ossifying Fibroma (NOF)2-Fibrous Dysplasia3-Ossifying Fibroma4-Desmoplastic Fibroma5-LipoSclerosing MyxoFibrous Tumor
(LSMFT)
1-Fibrous Cortical Defect (FCD) & Non-Ossifying Fibroma (NOF) :
a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-FCD typically occur in children (usually 2-15 yrs)
and indeed are one of the most common benign bony lesions which combined with NOF are seen in up to 30-40% of skeletally immature children / adolescents
b) Location :-Tibia and fibula are most commonly affected
(90%)
c) Radiographic Features :-Oval radiolucent defect, small (< 2-3 cm) in
FCD and larger in NOF with sclerotic margins
FCD
FCD
NOF
NOF
NOF
NOF
NOF
2-Fibrous Dysplasia :a) Incidenceb) Typesc) Radiographic Featuresd) Variants
a) Incidence :-Benign developmental anomaly in which the
medullary cavity is replaced with fibrous material, woven bone and spindle cells
-Fibrous dysplasia is found predominantly in children and young adults with 75% of patients presenting before the age of 30 years (highest incidence between 3 and 15 years)
b) Types :1-Monoostotic : single boneFemur, Ribs (most common)2-Polyostotic : multiple bones (often unilateral and
one limb)Femur, Tibia, Pelvis & Foot 3-Craniofacial fibrous dysplasia : skull and facial
bones alone4-Cherubism : mandible and maxilla alone (not
true fibrous dysplasia)
c) Radiographic Features :-Radiolucent expansile medullary lesions-Ground glass matrix-Well defined sclerotic margins1-Long Bones :-Bowing deformities-Shepherd's crook deformity (refers to a coxa
varus angulation of the proximal femur)-May lead to premature fusion of growth plates
leading to short stature
Shepherd’s Crook Deformity
Shepherd’s Crook Deformity
2-Base of the Skull :-Lesions tend to be sclerotic (in contrast to lucent lesions
elsewhere)3-Pelvis + Ribs :-Ribs are the most common site of monostotic fibrous
dysplasia , Fibrous dysplasia is the most common cause of a benign expansile lesion of a rib
-Bubbly cystic lesions-Fusiform enlargement of ribs-Protrusio Acetabuli (intrapelvic displacement of the medial
wall of the acetabulum)
Normal Pelvis Protrusio Acetabuli
Bilateral acetabular protrusio (white arrows) , the femoral head should not extend medial to a line drawn from the lateral aspect of the pelvis and the lateral aspect of the obturator foramen (blue line) , The distance between the acetabulum and the ilioischial line (yellow arrow) should not be > 3mm in males and >6 mm in females
FD of the Ribs
FD of the Ribs
Polystotic Form
Polystotic From
d) Variants :1-Cherubism :-Symmetrical involvement of mandible and maxilla2-McCune-Albright Syndrome :-Polyostotic unilateral fibrous dysplasia-Endocrine abnormalities (precocious puberty,
hyperthyroidism)-Café au lait spots-Predominantly in girls
3-Leontiasis ossea (craniofacial fibrous dysplasia) :
-Involvement of facial & frontal bones-Leonine facies (resembling a lion)4-Fibrous dysplasia (pseudarthrosis of
the tibia) :-Young infants-Anterior tibial bowing
3-Ossifying Fibroma :-They tend to occur in young children (often
under 10 years of age)-Lower extremity, tibia : commonest site
(90%)-Seen as a well-circumscribed lesion
4-Desmoplastic Fibroma :-The most common areas of involvement
include the mandible , pelvis and femur-Expansile lytic lesion containing thick
septations
5-LipoSclerosing MyxoFibrous Tumor (LSMFT) :
-Tends to have a striking predilection for the intertrochanteric region of the femur
-Typically seen as a geographic lytic lesion with a sclerotic margin
b) Malignant :1-Malignant Fibrous Histiocytoma2-Fibrosarcoma
1-Malignant Fibrous Histiocytoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-MFH are aggressive tumors which account
for 25-40% of all adult soft tissue sarcoma making them the most common type
-Old age-They are the most frequent soft tissue
sarcoma to occur as a result of radiotherapy and are also seen on a background of Paget disease
b) Location :-Although MFH can occur almost anywhere
in the body, they have a predilection for the retroperitoneum and proximal extremities
-They are usually confined to the soft tissues but occasionally may arise in or from bone (1-5%)
c) Radiographic Features :-Aggressive malignant criteria-Density of tumor is similar to muscle (10 to 60
HU)-MRI :*T1 : intermediate (to low) signal intensity similar to
adjacent muscle*T2 : intermediate to high signal intensity*T1+C : prominent enhancement of solid
components
T1
T2
T1+C
2-Fibrosarcoma :-Fibrosarcoma & MFH are clinically &
radiologically indistinguishable
(iv) Bone Marrow Tumors :1-Eosinophilic Granuloma2-Multiple Myeloma3-Ewing’s Sarcoma4-Primary Lymphoma5-Leukemia
1-Eosinophilic Granuloma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Age : 1st to 3rd decade-Type of Langerhan’s Cell Histiocytosis
which is confined to bone
b) Location :-Skull, most common-Pelvis-Spine-Long bones -Mandible
c) Radiographic Features :1-Plain Radiography2-MRI
1-Plain Radiography :a) Skullb) Mandiblec) Spined) Long Bones
a) Skull :-Solitary or multiple punched out lytic lesions with
or without sclerotic rim-Double contour or beveled edge appearance may
be seen due to greater involvement of the inner than the outer table (hole within hole sign)
-Button sequestrum (bone opacity surrounded by a relatively well-defined lucent area)
-Geographic skull (destructive lytic bone lesion , edges of which may be bevelled, scalloped or confluent)
On the left , lateral skull radiograph demonstrates two lytic lesions in the frontal and parietal bones (white circles) with characteristic "beveled edges” , The CT scan (at right) shows the lesion in the right frontal bone (white arrow) and the beveling of the destructive process
Beveled edge
Button sequestrum
Button sequestrum
Geographic skull
b) Mandible :-Irregular radiolucent areas mostly involving
superficial alveolar bone-Floating tooth : loss of lamina dura
Floating tooth
c) Spine :-Vertebra plana : Complete collapse of the vertebral body,
more often in thoracic spine
Vertebra plana
Vertebra plana
d) Long Bones :-Mainly involves diaphysis and respect
growth plates-Lytic lesion
Hole within a hole sign (multifocal eosinophilic granulomatosis in which two lucent lesions of unequal size overlie one another , the smaller lucent focus appears as an area of additional lucency within the larger osteolytic focus)
2-MRI :*T1 : typically low signal *T2 : isointense to hyperintense*STIR : hyperintense *T1+C : shows contrast enhancement
T1
T2
FLAIR T1+C
2-Multiple Myelomaa) Incidenceb) Locationc) Typesd) Radiographic Featurese) Differential Diagnosis
a) Incidence :-The most common primary malignant bone
neoplasm in adults
b) Location :-Vertebrae (most common), vertebral bodies are
destroyed before the pedicles are, as opposed to metastases in which pedicles are destroyed first
-Axial skeleton is most commonly affected (skull, spine, ribs & pelvis)
c) Types :1-Multiple myeloma (multiple lesions) :-Axial skeleton2-Solitary plasmacytoma :-Common in vertebral body, pelvis & femur
d) Radiographic Features :1-Diffuse Pattern : Two appearances a) Numerous well circumscribed lytic bone lesions
(more common), punched out lucencies e.g. pepperpot skull or raindrop skull with endosteal scalloping
b) Generalized osteopaenia (less common), often associated with vertebral compression fractures / vertebra plana
2-Plasmacytoma : tends to be large and expansile
Pepperpot skull , rain drops
Pepperpot skull , rain drops
Endosteal scalloping
With generalized osteopenia
-MRI : 1-Replacement of normal marrow (sensitive)2-Normal fatty marrow is bright on both T1
and T2, while abnormal marrow is dark
e) Differential Diagnosis :-The main differential is that of widespread bony
metastases-Findings that favor the diagnosis of bony
metastases over that of multiple myeloma include :1-More commonly affect the vertebral pedicles rather
than vertebral bodies2-Rarely involve mandible, distal axial skeleton3-Although both entities have variable bone scan
appearances (both hot and cold) unlike myeloma, extensive bony metastases rarely have a normal appearance
3-Ewing’s Sarcoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-The second most common primary bone
tumor of childhood after osteosarcoma-Typically occurs in children and
adolescents between 10 and 20 years of age (95% between 4 and 25 years of age)
b) Location :-Diaphysis of lower limb : 45%, femur most
common-Pelvis : 20%-Upper limb
c) Radiographic Features :-Aggressive malignant criteria-Ewing sarcomas tend to be large poorly
marginated tumors with over 80% demonstrating extension into adjacent soft tissues
-Laminated (onion skin) periosteal reaction
Onion peel periosteal reaction
Frontal radiograph and lateral radiographs of the femurdemonstrate mottled osteolytic lesion (blue circle) with poorly marginated edges in the diaphysis of the bone , there is sunburst periosteal reaction (red circle) and lamellated periosteal reaction (white arrows)
4-Primary Lymphoma :-Very rare, most osseous lymphomas are
secondary-Primary osseous lymphoma is usually of
non-Hodgkin's type-Permeative lytic lesion with similar
appearance to other small round cell tumors (e.g. Ewing's tumor)
5-Leukemia :a) Metaphyseal lucent band b) Generalized reduced bone density
(osteopenia)c) Lytic bone lesionsd) Metaphyseal cortical bone erosionse) Collapsed vertebraf) Widening of sutures and periosteal
reactions
Metaphyseal lucent band (arrow) in radial and ulnar metaphyses , note the lucent bony lesions of the first and third metacarpal bone on the right side (arrows)
Metaphyseal hypodensity on both femurs with sclerotic lesions (arrows) , there are also lytic lesions in the left femoral neck (arrowhead)
Metaphyseal translucency in both distal femurs and proximal tibiae more prominent in the latter
Multiple collapsed vertebrae
(v) Other Bone Tumors :1-Simple Bone Cyst2-Aneurysmal Bone Cyst3-Hemophiliac Pseudotumor4-Giant Cell Tumor5-Intraosseous Hemangioma6-Adamantinoma
7-Chordoma8-Intraosseous Lipoma9-Hemangioendothelioma10-Angiosarcoma11-Massive Osteolysis (Gorham’s Disease)12-Glomus Tumor
1-Simple Bone Cyst : Unicamerala) Incidenceb) Locationc) Radiographic Featuresd) Differential Diagnosis
a) Incidence :-Common benign lucent bony lesions that
are seen in childhood and typically remain asymptomatic
-They usually found in children in the 1st and 2nd decades
b) Location :-Most common location : proximal
metaphysis of the humerus or femur-Older patients : calcaneus and ileum
c) Radiographic Features :-Central (intramedullary) location-Expansile lesion, fluid-filled cavities (fluid-
fluid levels)-If there is fracture through this lesion a
dependent bony fragment may be seen and this is known as the fallen fragment sign
Fallen fragment sign
Calcaneal cyst
d) Differential Diagnosis :Expansile bone lesions : FENGOMASHIC1-Fibrous dysplasia2-Enchondroma3-Giant cell tumor4-Osteoblastoma5-Myeloma6-Aneurysmal bone cyst7-Simple bone cyst8-Hyperparathyroidism9-Infection (Hydatid)10-Chondroblastoma
2-Aneurysmal Bone Cyst : (ABC)a) Incidenceb) Locationc) Typesd) Radiographic Features
a) Incidence :-Benign expansile tumor like bone lesion -Primarily seen in children and adolescents
with 80% occurring in the patients less than 20 years of age
b) Location :-They are typically eccentrically located in
the metaphysis of long bones adjacent to an unfused growth plate
-Long bones : tibia and fibula-Spine : posterior elements-Pelvis
c) Types :1-Primary Non-Neoplastic Lesion, 70 %2-Secondary Lesion, 30 % :-Secondary to underlying lesions :a) Chondroblastomab) Fibrous dysplasiac) Giant cell tumor (GCT)d) Osteosarcoma
d) Radiographic Features :-Eccentric location-Sharply defined expansile osteolytic lesions with
thin sclerotic margins-Fluid fluid level -MRI :The cysts are of variable signal with surrounding
rim of low T1 and T2 signal , focal areas of high T1 and T2 signal are also seen presumably representing areas of blood of variable age
3-Hemophiliac Pseudotumor :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Rare complication that occurs in 1-2% of
hemophilia-Pathologically , pesudotumors represent
hematomas with thick fibrous capsule
b) Location :-Most develop in the muscles of the pelvis
and lower extremity where the large muscles have a rich blood supply or in bone following intraosseous bleeding
-Femur , pelvis & tibia
c) Radiographic Features :1-Soft tissue lesions : -Large soft tissue mass with adjacent bone
destruction-Calcifications common-MRI shows characteristic appearance of
hematoma , fluid-blood levels may be present-Bleeding in a joint (hemoarthrosis) :Widened joint space , increase bone
trabeculations and elevated periosteum by soft tissue mass
-Hemophilia and soft tissue pseudotumor with secondary infection
-Anteroposterior view shows extensive soft tissue mass in right thigh resulting in extrinsic cortical erosion (arrowheads) of femoral shaft
-Skin defect and air bubbles reflect secondary infection and skin necrosis
-Note hemophilic involvement of knee joint
2-Intraosseous Lesions :-Well defined unilocular or multiloculated
lytic expansile lesions of variable size-It can involve metadiaphysis and epiphysis
of long bones-Other findings include endosteal
scalloping , perilesional sclerosis , cortical thinning or thickening , trabeculations and septations
-Pathological fractures can also be present
4-Giant Cell Tumor : (Osteoclastoma)a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Relatively common bone tumors usually benign
and typically found in the metaepiphysis of long bones
-After epiphyseal closure > 18 years of age
b) Location :-Around the knee : distal femur and proximal tibia-Distal radius
c) Radiographic Features :-Occurs only with a closed growth plate-Expansile lytic subarticular-No sclerotic margins
5-Intraosseous Hemangioma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Relatively common-Typically seen in the 4th-5th decade of life
b) Location :-Vertebral body > skull > face
c) Radiographic Features :-Sclerotic vertebra with vertical trabeculae , Corduroy sign-MRI :*T1 : high (fat rich)-Intermediate to low signal intensity is seen in fat poor
hemangioma*T2 : high*T1+C : enhancement is often present -Radiolucent slightly expansile intraosseous lesion in
extraspinal sites
T1 T2
6-Adamantinoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Ameloblastoma (previously known as
an adamantinoma of the jaw) are benign locally aggressive tumors that arise from the mandible
-Ameloblastoma is the second most common odontogenic tumor (odontoma is the most common)
-They are slow growing and tend to present in the 3rd to 5th decades of life
b) Location :-Mandible-Less commonly from the maxilla-May occur in the tibia (adamantinoma) ,
bone destruction in the anterior tibial shaft
c) Radiographic Features :-Multiloculated (80%) lytic expansile soap-bubble
lesion with well demarcated borders and no matrix calcification
-Occasionally erosion of the adjacent tooth roots can be seen which is highly specific
-When larger it may also erode through cortex into adjacent soft tissues
-MRI : In general ameloblastoma shows a mixed solid and cystic pattern with a thick irregular wall often with papillary solid structures projecting into the lesion , these components tend to vividly enhance
Maxillary ameloblastoma
7-Chordoma :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Uncommon malignant tumor -Chordoma is usually seen in adults (30-60
years)-Chordoma is the most common primary
malignant sacral tumor
b) Location :1-Sacro-coccygeal :-Most common-Involving particularly the fourth and fifth sacral
segments 2-Speno-occipital (clivus) :-Typically the mass projects in the midline posteriorly
indenting the pons (thumb sign) 3-Vetebral bodies :-Commonly involve the cervical spine (particularly C2)
followed by the lumbar spine then the thoracic spine
c) Radiographic Features :-Nonspecific expansile lytic lesion-Large soft tissue component-Variable calcification
8-Intraosseous Lipoma :-Rare benign lesion, however the most
common lipogenic tumor in bone-Osteolytic bone lesion with well-defined margins-CT : Far attenuation-MRI : Fat attenuation, hyperintense fat signal on
T1 and T2 that will be entirely suppressed by STIR or fat saturated sequences
9-Hemangioendothelioma :-Low-grade malignant lesion of adolescents-Multifocal lytic lesions involving multiple
bones of a single extremity usually the hands or feet
-Locally aggressive , rarely metastasize
10-Angiosarcoma :-Highly malignant vascular tumor of
adolescents / young adults-One third are multifocal-Commonly metastasize
11-Massive Osteolysis (Gorham’s Disease) :-Extensive cystic angiomatosis (hemangiomatous
and lymphangiomatous) of bone in children and young adults
-Idiopathic-Location : shoulder and hip most common-Intramedullary or subcortical lucent foci may be
the earliest manifestation , this progresses to profound osteolysis with resorption of affected bone and lack of compensatory osteoblastic activity or periosteal reaction
12-Glomus Tumor :-Benign vascular tumor of the terminal
phalanx-Well-circumscribed lytic and painful-Clinical pain and terminal phalangeal
location are characteristic
(vi) Metastases :a) Incidenceb) Etiologyc) Locationd) Radiographic Featurese) Secondary Lymphoma
a) Incidence :-Skeletal metastases account for 70% of all
malignant bone tumors-More with lung cancer , breast cancer ,
renal cell carcinoma and prostate cancer (account for approximately 80% of all skeletal metastases)
b) Etiology :1-Adult Male :-Prostate-Lung-Kidney2-Adult Female :-Breast-Lung-Kidney
3-Child :-Neuroblastoma-Lymphoma / Leukemia-Medulloblastoma-Sarcoma-Wilm’s Tumor
c) Location :1-Vertebrae , especially posterior vertebral
body extending into pedicles2-Pelvis3-Proximal femur4-Proximal humerus5-Skull
d) Radiographic Features :1-Lytic metastases :-Kidney-Lung-Thyroid-Breast2-Sclerotic metastases :-Breast -Prostate
3-Mixed lytic and sclerotic metastases :-Breast carcinoma, typically lytic but 25 % are
mixed-Lung carcinoma, typically lytic but 15 % are mixed-Carcinoma of the cervix-Testicular tumors-Prostate carcinoma , typically sclerotic but 15 %
are mixed4-Metastases may be diffuse, focal or expansile
*N.B. :-Destructive lesion in the pelvis of an adult
>>> metastases-Single dense vertebra (Ivory Vertebra) :1-Osteoblastic Metastases2-Lymphoma3-Paget’s Disease
Ivory vertebra
Ivory vertebra
e) Secondary Lymphoma :-Skeletal abnormalities occur in 5%-50% of all
lymphomas-Radiographic Features :*Usually aggressive tumors with no specific
pathognomonic finding*Suspect the diagnosis in lymphoma patients*Ivory vertebra is a manifestation of Hodgkin's
lymphoma , lymphoma causes increased bone density of the affected vertebrae but it is usually accompanied by a destructive pattern and large soft tissue mass
Lymphoma of L3 , note the destructive pattern of the bone and the soft tissue mass on CT (arrow)
(vii) Miscellaneous :1-Mastocytosis2-Myelofibrosis3-Pyknodysostosis4-Radiation Induced Changes5-Soft Tissue Tumors6-Pigmented Villonodular Synovitis7-Synovial Chondromatosis
1-Mastocytosis :Mast cell infiltration of skin , marrow and
other organs-Results in mixed lytic / sclerotic process
(dense bones) with thickened trabecula-Focal or diffuse (more common)-In some patients there is generalized
osteoporosis with risk of pathological fractures
2-Myelofibrosis : (Myeloid Metaplasia)-Is a hematological disorder where there is
replacement of bone marrow with collagenous connective tissue and progressive fibrosis
-It is also classified as a myeloproliferative disorder-Radiological Findings :*Diffuse or patchy osteosclerosis*Massive extramedullary hematopoiesis*Massive splenomegaly (100%)*Hepatomegaly*Paraspinal mass
-Differential Diagnosis of Osteosclerosis :Regular Sex Makes Occasional Perversions Much More
Pleasurable And Fantastic :1-Renal osteodystrophy2-Sickle cell anemia / Thalassemia3-Myelofibrosis4-Osteopetrosis5-Pyknodystosis6-Metastases7-Mastocytosis8-Paget’s disease9-Athletes10-Fluorosis
3-Pyknodysostosis :a) Incidenceb) Radiographic Features
a) Incidence :-Rare autosomal recessive bone
dysplasia characterised by osteosclerosis and short stature
b) Radiographic Features :1-Hands2-Cranial & Maxillofacial3-Other
1-Hands :-Short stubby fingers-Partial agenesis / aplasia of terminal
phalanges simulating acro-osteolysis-Delayed bone age
2-Cranial & Maxillofacial :-Marked delay in sutural closure-Wormian bones (lambdoidal region) ,
small intrasutural bones that lie between the cranial sutures formed by the bones of the skull vault
-Micrognathia (small mandible)-Straight mandible-Persistence of primary teeth
(A) Panorex radiograph reveals multiple disorganized crowded deciduous and permanent teeth within the expanded alveolar processes , (B) Wormian bones (arrows) within the lambdoid suture , obtuse angle of the mandible and dental abnormalities are also visualized
3-Other :-Osteosclerosis (of vertebral bodies)-Underdeveloped paranasal sinuses and
mastoid air cells-Hypoplastic clavicles-Erosion of outer end of clavicles
4-Radiation Induced Changes :a) Bone Growth b) Osteonecrosis c) Radiation-Induced Bone Tumors
a) Bone Growth :-The major effect of radiation is on
chondroblasts in epiphyses : 1-Epiphyseal growth arrest 2-Slipped capital femoral epiphysis3-Scoliosis (e.g. after radiation of Wilms'
tumor)4-Hemihypoplasia (i.e. iliac wing)
b) Osteonecrosis :-Radiotoxicity to osteoblasts results in
decreased matrix production -Radiation osteitis is most common in :1-Mandible , 30% (intraoral cancer)2-Clavicle , 20% (breast carcinoma)3-Humeral head , 14% (breast carcinoma)4-Ribs , 10% (breast carcinoma)5-Femur , 10%
c) Radiation-Induced Bone Tumors :1-Enchondroma (exostosis) is the most
common lesion2-OSA , chondrosarcoma and MFH are the
most common malignant lesions
5-Soft Tissue Tumors :a) Malignant Fibrous Histiocytoma b) Liposarcoma c) Synovial Cell Sarcomad) Fibromatoses
a) Malignant Fibrous Histiocytoma :-See before
b) Liposarcoma :-Second most common soft tissue tumor in
adults-Location : buttocks , lower extremity &
retroperitoneum-Fatty component is progressively replaced
by soft tissue while degree of malignancy increases
-Variable reactive pseudocapsule
c) Synovial Cell Sarcoma :Soft tissue sarcoma-Age : 15 to 35 years-Location : most commonly around the knee-Approximately one third contain
calcifications
d) Fibromatoses :A spectrum of fibrous soft tissue lesions that
are infiltrative and prone to recurrence
6-Pigmented Villonodular Synovitis : (PVNS)
a) Incidenceb) Locationc) Typesd) Radiographic Features
a) Incidence :-Results from synovial proliferation and
hemosiderin deposition-Affects adults in their second to fourth
decades
b) Location :-knee (far the most frequently affected joint)
66-80%-Hip-Ankle-Shoulder
c) Types :1-Diffuse (within the joint)2-Focal
d) Radiographic Features :1-Plain Radiography & CT :-Soft tissue swelling around joint , from
effusion and synovial proliferation-Never calcify-Multiple sites of deossification appearing as
cysts-No joint space narrowing (until late)
AP and lateral views of the knee demonstrate marked soft tissue swelling , cystic changes in both the femur and tibia without significant joint space narrowing
2-MRI : Hemosiderin-Diffuse low signal masses on T1W and
T2W sequences lining the joint synovium-Joint effusion
7-Synovial Chondromatosis :a) Incidenceb) Locationc) Radiographic Features
a) Incidence :-Benign monoarticular disorder of unknown
origin that is characterised by multiple intra-articular cartilaginous loose bodies
-Most present in the 4th or 5th decade of life
b) Location :-Usually the condition is monoarticular with
large joints preferentially affected-The knee is the most commonly affected
joint (involved in up to 70% of cases) followed by the hip (20%) , elbow and shoulder
c) Radiographic Features :1-Plain Radiography & CT :-When extensive ossification is present then
many calcific joint bodies are present either fully ossified or demonstrating the ring and arc calcification characteristic of chondroid calcificaiton
-They are most often multiple and of uniform size
2-MRI :-Typical chondroid signal characteristic :Lobulated intra-articular mass *T1 : intermediate to low signal*T2 : high signal containing multiple foci of low signal
intensity
