MSK radiology: DDx and disease properties
Terms
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- Bubbly or lytic bone lesion
-
FEGNOMASHIC
Fibrous dysplasia
EG, Enchondroma
GCT
NOF
Osteoblastoma
Mets, Myeloma
ABC
SBC
Hyperparathyroidism
Infection
Chondroblastoma - Multiple lytic bone lesions
-
FEEMHI
Fibrous dysplasia
Enchondromas
EG
Mets, myeloma
Hyperparathyroidism
Infection - Rib lesions
-
FAME
Fibrous dysplasia
ABC
Mets, myeloma
Enchondroma, EG -
Lytic epiphyseal lesion
(also apophyseal, carpal and tarsal bones, patella) -
COGEM
Chondroblastoma (if <40 yo)
Osteomyelitis
GCT, geode
EG
Mets/myeloma (if >40yo) - Lytic lesion in posterior elements of spine
-
OAT
Osteoblastoma
ABC
TB -
Lytic bone lesion in a patient over 30 -
which lesions to LEAVE OUT of the ddx? -
CANES
Chondroblastoma
ABC
NOF
EG
SBC - Bony sequestrum in a lytic lesion
-
FILE
Fibrosarcoma
Infection
Lymphoma
EG
osteoid osteoma (mimic) - Causes of geodes
-
CARD and T
CPPD
AVN
RA
DJD
Trauma - Sclerotic bone lesion
-
If over 40, METS (P,B,HL)
20-40 yo:
chondroblastoma
ABC
NOF
EG
SBC
fibrous dysplasia
infection
HPT (healing brown tumor)
osteoid osteoma
giant bone island - Bone lesion with endosteal scalloping
-
Fibrous dysplasia
enchondroma
cartilaginous tumor - Aggressive lytic bone lesion under age 10
-
Ewing's
Osteosarcoma
Lymphoma
Osteomyelitis
EG -
Aggressive lytic bone lesion
age 10-20 -
Osteosarcoma
Ewing's sarcoma
Lymphoma
Osteomyelitis -
Aggressive lytic bone lesion
age 20-30 -
Osteosarcoma
Lymphoma
Ewing's
MFH
Osteomyelitis -
Aggressive lytic bone lesion
age 30+ -
Myeloma/mets
Lymphoma
Chondrosarcoma
Fibrosarcoma/MFH
Osteosarcoma
Osteomyelitis - Permeative bone lesion in child:
-
Ewing’s and other round cell CA
infection
EG - Permeative lesion in older pt
-
infection
mets, myeloma
MFH
reticulum cell sarcoma - Soft tissue tumors
-
MFH
liposarcoma
synovial sarcoma
synovial osteochondromatosis
PVNS
hemangiomas -
Malignant transformation of bony lesions:
fibrous dysplasia - fibrosarcoma, OSA, MFH
- Malignant transformation of bony lesions: Paget’s
- OSA
-
Malignant transformation of bony lesions:
osteomyelitis with draining sinus - SCC
- Malignant transformation of bony lesions: radiation tx
- OSA, chondrosarcoma, MFH
- Malignant transformation of bony lesions: bone infarct
- fibrosarcoma, MFH
- Malignant transformation of bony lesions: Ollier’s
- chondrosarcoma
- Malignant transformation of bony lesions: Maffucci’s
- chondrosarcoma
- Malignant transformation of bony lesions: osteochondroma
- chondrosarcoma
-
Cortical holes
(pseudopermeative lesion) -
- osteoporosis
(metacarpal cortex < 1/4-1/3 of metacarpal)
- radiation
- hemangiomas - Focal cortical thickening
-
stress fracture
infection
osteoid osteoma - Mets to bone (typical blastic and lytic)
-
PBKTL
P – mostly blastic
B – mixed
K – purely lytic
TL – mostly lytic - Hallmarks of DJD
-
joint space narrowing (asymmetr)
subchondral sclerosis
osteophytes
subchondral cysts
lack of osteoporosis or erosions - Joints that exhibit erosions with OA
-
TMJ
SI
AC
pubic symphysis - Hallmarks of RA
-
-hands – proximal. Ulnar dev.
-bilaterally symmetric
-marginal erosions (incl uln styloid & triquetr)
-periart & diff osteoporosis, subchondral cysts
-ST swelling
-jt space narrowing (JSN)
-carpal instability, rotator cuff tear
-distal clavicle resorption
-protrusio acetabuli, A-a subluxation
-2˚ DJD – severe JSN >> sclerosis & osteophytes - Hallmarks of fibrous dysplasia
-
- NO periosteal rxn
- mention adamantinoma if in tibia or jaw
- Typical: pelvis, prox femur, ribs, skull
- "long lesion in long bone"
- expansile medullary lytic lz w/ground glass; well-def sclerotic margin
- bowing deformities; base of skull sclerotic
- hot on bone scan
- cherubism-mandible & maxilla
- craniofacial -facial & frontal bones
- pseudoarthrosis of tibia
- Mccune Albright -polyostotic FD with café-au-lait spots &precocious puberty) - Hallmarks of enchondroma
-
- must have Ca++ expt in phalanges
- no periostitis
- tubular bones
- chondroid calcifications
- endosteal scalloping
- pain is malignant
- Ollier’s enchondromatosis, Mafucci’s enchondromatosis with multiple ST hemangiomas) - Hallmarks of EG
-
- age<30
- lytic lesion can look aggressive
- skull lesion beveled-edge appearance
- sequestrum
- floating tooth
- vertebra plana
- lung dz, pituitary, RES - Lytic lesion, considering NOF, features to think of
-
- age<30
- no periostitis
- cortically based
- metaphysis
- also mention chondromyxoid fibroma - Characteristics of ABC
-
- age<30, painful
- expansile, eccentric
- fluid-fluid levels on MR
- post elem spine, metaph long bones, pelvis
- also mention osteoblastoma - Characteristics of SBC
-
- age<30
- central, no periostitis
- prox humerus, prox femur, calcaneus
- fallen fragment sign - features of multiple myeloma
-
- age>40
- plasmacytoma in ilium & sacrum,
- cold on bone scan; do skel survey
- vert bodies destroyed before pedicles
- axial skeleton, long bones, punched-out lytic lesions, generalized osteopenia - features of osteosarcoma
-
- ill-defined intramedullary metaphyseal mass
- extends through cortex
- osteoid or chondroid matrix
- aggressive periost rxn (Codman or sunburst)
- telangiectatic form - purely lytic, mimics ABC
- parosteal form - low-grade, seen in post distal femur w/ more mature ossification centrally - Hallmarks of HLA-B27 spondyloarthropathies
-
bony ankylosis
proliferative new bone formation
predom axial (spinal)
syndesmophytes -
arthritic involvement of SI joints
Differential and considerations -
- AS (bamboo spine, Andersen lesion and pseudoarthrosis),
- IBD (like AS)
- psoriasis (distal jts, sausage digit, pencil-in-cup, acroosteolysis, proliferative erosions, STS, periostitis, ankylosis, arthritis mutilans deformities, heel spur w fuzzy margins
- Reiter’s syndrome (like psoriasis but feet>hands, IP joint great toe),
- DJD, gout
- infection
- HPT
bilat + symmetric SIJ + marginal symmetric syndesmophytes – usually AS or IBD
unilateral or asymmetric SI jt – NOT AS and IBD, consider psoriasis and Reiter’s - Large joint involvement in arthritis
-
- DJD (superolateral migration in hips, medial compartment of knee most affected),
- RA (axial migration in hips),
- CPPD
- AS (resembles RA)
- PVNS, synovial osteochondromatosis,
- infection (S. aureus most comm, Salmonella in sicklers; + effusion, + joint destruction, crosses vert discs, periosteal rxn, bone destruction, Brodie’s abscess is well-defined lytic lesion with thick sclerotic border, sequestrum)
- amyloidosis (nodular synovitis with erosions resembling RA)
- ochronosis (DSN with vacuum, disc calcifications, generalized osteoporosis, secondary OA) - Arthropathy distribution in hands and wrists:
-
Distal – OA, psoriasis, Reiter’s
Proximal – RA, CPPD
Ulnar styloid - RA - Bilateral symmetry of arthropathy
-
- Primary OA (middle-aged F in hands only, 1st CMC, gull-wing erosive pattern)
- RA
- multicentric reticulohistiocytosis (mult erosions mostly phalanges NO osteoporosis) - Monoarticular arthritis
-
CHRIST:
- Crystal arthropathies
- Hemophilia
- RA
- Infection
- Synovial (synovial osteochondromatosis, PVNS)
- Trauma - Hallmarks of gout
-
- erosions w/ sclerotic borders or overhanging edges
- soft tissue nod (can calcify w/ renal failure)
- in hands –random dist, NO osteoporosis
- podagra (1st MTP jt)
- often have chondrocalcinosis
- preserved joint space
- olecr/prepatellar bursitis - Madelung’s deformity
-
HITDOC:
- Hurler’s
- Infection
- Trauma
- Dyschondrosteosis
- Osteochondromatosis
- Chromosomal anom (Turner’s) - Erlenmeyer flask deformity
-
CHONG
- Craniometaphyseal dysplasia
- Hemoglobinopathies
("hair on end" skull
extramed. hematopoiesis)
- Osteopetrosis
- Neimann-Pick
- Gaucher's - Arthritis with normal mineralization
-
DJD
CPPD
Gout
multi. reticulohistiocytosis
PVNS
synovial osteochondromatosis - Epiphyseal enlargement and gracile diaphyses
-
- hemophilia (hemarthrosis, 2˚ OA, wide intercond notch, big trochlear notch, subchondral cysts; pseudotumor – ST mass w/ adj bone destruction, hematoma, Ca++ common)
- JRA (diff ankylosis of post articular joints, periosteal new bone, STS, short metacarp)
- paralysis - Causes of AVN
-
ASEPTIC
-Anemia (SC), Amyloid
-Steroids
-Ethanol
-Pancreatitis, Pregnancy
-Trauma
-Idiopathic (L-C-P)
-Caisson dz, CVD - Tendon rupture
-
steroids
RA
DM
HPT
gout - Polydactyly
-
familial
chondroectodermal dysplasia
trisomy 13
Meckel-Gruber - Radial hypoplasia
-
VACTERL
Holt-Oram syndrome
Thrombocytopenia-absent radius syndrome - Distal tuft resorption
-
PINCH FO
Psoriasis
Injury (thermal)
Neuropathy (DM, leprosy)
CVD (Raynaud's, scleroderma)
Hyperparathyroidism
Familial (Hajdu-Cheney)
Other - PVC tox - Periostitis without underlying bony lesion
-
- Trauma
- HPO (pain, long bones; lung/ pleural CA, mets, chron PNA)
- Venous stasis (legs)
- Thyroid acropachy (post thyroidectomy, metacarpals & phalanges, esp ulnar aspect of 5th metacarpal)
- Pachydermoperiostosis (like HPO but rarely painful) - Ivory vertebral body
-
LIMP
– Lymphoma
- Infection
- Mets, myeloma
- Paget’s - Ddx for diffuse dense bones
-
Neoplasm
Mets, Myelofibrosis
Mastocytosis, Lymphoma
Congenital
Craniotubular dysplasia
Osteopetrosis
Pyknodysostosis
Sickle cell
Metabolic
Paget's
Renal osteodystrophy
Fluorosis
Hypervitaminosis A&D - Periosteal reaction in children
-
SCALP NIT
-Scurvy (dense metaph lines)
-Caffey's (tib, ulna, mandib)
-A hypervitaminosis
-Lymphoma/leukemia
-Physiologic, prostaglandins
-Neuroblastoma
-Infection
-Trauma - Widened pubic symphysis
-
bladder exstrophy
infection
mets
trauma
pregnancy - Hallmarks of collagen vascular diseases
-
osteoporosis and ST wasting in the hands, usually no erosions
SLE - ulnar deviation of phalanges, nonerosive, resembles Jaccoud’s arthropathy
Scleroderma - ST Ca++, acroosteolysis, severe resorption of 1st CMC with radial subluxation of 1st metacarpal
Dermatomyositis - widespread ST Ca++, radial subluxation of IP joint of thumb - CPPD-associated disorders
-
primary HPT
gout
hemochromatosis
(DJD 2nd-4th MCP jts with squaring of metacarpal heads with drooping osteophytes, generalized osteoporosis) - Hallmarks of CPPD
-
- pain
- cartilage Ca++ (knee, triangular fibrocartilage of wrist, pubic symphysis)
- joint destruction from secondary DJD (shoulder, elbow, radiocarpal jt, patellofemoral jt)
- subchondral cysts, can mimic gout - Lytic skull lesion
-
SCD
HPT
Paget’s
FD
TS
infection
mets, myeloma
EG, epidermoid
hemangioma - Lytic finger
-
- Enchondroma
- Glomus tumor (pain, terminal phalanx)
- Epidermoid inclusion cyst
- Mets
- Infection
- Sarcoid
- Erosive arthropathy - Dense metaphyseal lines
-
- Growth recovery lines
- Lead
- Healing rickets
- Scurvy -
Important features of
achondroplasia -
- shortened long bones w/ narrowing of interpedicular distance in caudal direction
- posterior vert body scalloping - Important features of melorrheostosis
-
- thickened cortical new bone like “dripping candle waxâ€
- follows sclerotome - Important features of mucopolysaccharidoses
-
- flattened vertebral bodies with anterior beak
- flared iliac wings and broad femoral necks
- pointed proximal 5th metacarpal base w/notch look to ulnar aspect
- posterior vertebral body scalloping -
Important features of
multiple hereditary exostosis -
- osteochondromas
- metaphyseal
- lesion grows away from joint, undertubulation, knees, proximal femur, axial more prone to degeneration -
Important features of
osteoid osteoma -
- pain, age<30
- lucent nidus surr by reactive sclerosis in cortex of long bone
- can be on concave side of painful scoliosis
- “double density†sign on bone scan -
Important features of
osteopathia striata -
- multiple 2-3mm thick linear bands of sclerotic bone aligned parallel to long axis of bone
- asymptomatic -
Important features of
acromegaly -
- skull thickening
- enlarged sinuses & sella
- hypertrophied terminal tufts w/ spade appearance
- posterior vertebral body scalloping
- elongated & wide vert bodies
- heel pad thickening -
Important features of
transient osteoporosis of the hip -
- pain
- self-limited
- low T1 signal
- hot on bone scan - Features of intraosseous lipoma
-
- asymptomatic
- proximal femur, fibula, calcaneus
- may have central calcified nidus - Lytic lesion in sacrum
-
- Mets
- Chordoma (sacral, clivus, vert body - expansile lytic lz w/ST component)
- Plasmacytoma
- Chondrosarcoma
- GCT - Posterior vertebral scalloping
-
- dural ectasia (NF, Marfan’s, Ehlers-Danlos)
- syrinx
- spinal canal tumor
- Congenital (achondroplasia, mucopolysacchar, OI)
- Acromegaly - Protrusio acetabuli
-
- RA
- Paget’s
- AS
- Trauma
- IBD
- Osteomalacia - Distal clavicle resorption
-
RA
HPT
osteomyelitis
weightlifting
trauma
scleroderma - Platyspondyly
-
Diffuse
----Dwarfism
----OI
----Morquio’s
----epiphyseal dysplasia
----Cushing’s
Solitary or multifocal
EG
infection
trauma
mets, myeloma
lymphoma, leukemia
SCD
osteonecrosis -
Charcot joint
features -
6 Ds
Dense subchondral bone (sclerosis)
Degeneration (attempted repair)
Destruction (margins may appear surgical)
Deformity
Debris (loose bodies)
Dislocation (nontraumatic) - Wormian Bones DDx
-
-Pyknodysostosis
-Osteogenesis Imperfecta
-Rickets in healing
-Kinky Hair Syndrome
-Cleidocranial Dysostosis
-Hypothyroidism
-Otopalatodigital syndrome
-Pachydermoperiostosis
-Primary Acro-osteolysis (Hajdu-Cheney)
-Syndrome of Down
-Idiopathic (can be normal, esp.<6 mo.) -
DDx:
Arthritis Affecting the DIPs -
Psoriatic Arthritis
Osteoarthritis
Erosive osteoarthritis
Multicentr reticulohistiocytosis - Arthritis With Periostitis ddx
-
Juvenile Rheumatoid Arthritis
Infectious arthritis
Reiter’s syndrome
Psoriatic Arthritis - Charcot joint causes
-
DS6
Diabetes (insensitivity to pain)
Syphilis (Tabes Dorsalis)
Steroids
Spinal cord injury
Spina bifida
Syringomyelia
Scleroderma -
DDx
Lytic Lesion Surrounded by Marked Sclerosis -
BOOST
Brodie’s Abscess
Osteoblastoma
Osteoid osteoma
Stress fracture
Tuberculosis - Causes of basilar invagination
-
Paget’s disease
Fibrous Dysplasia
Rickets
OI, Osteomalacia
Achondroplasia
Cleidocranial dysplasia
Hyperparathyroidism, Hurler’s - "Rugger Jersey⬝ Spine
-
"OH My"
Osteopetrosis
Hyperparathyroidism
Myelofibrosis - Vertebra Plana ddx
-
Myeloma / Metastases
EG / Ewing’s
Lymphoma / Leukemia
Trauma (fx)/TB (infection) - Posterior vertebral body scalloping ddx
-
NO MAAM
Neurofibromatosis (NF)
Osteogenesis Imperfecta (OI)
Marfan’s syndrome
Achondroplasia (dwarf)
Acromegaly
Mucopolysaccharidosis - Osteoblastic metastases
-
"5B's Lick Pollen"
Bronchogenic (carcinoid)
Bladder
Breast
Brain (medulloblastoma, GBM)
Bowel (mucinous, carcinoid)
Lymphoma
Prostate Ca - Dense base of skull DDx
-
-Fibrous dysplasia
-Engelmann’s (kids, cort thickening midshaft long bones inv periost & endost surf)
-Von Buchem’s disease (adults)
-Paget’s disease, -Pyknodysostosis
-Meningioma
-Osteopetrosis -
Heel pad thickening
(> 25mm) DDx -
Myxedema,
Acromegaly
Dilantin
Callus
Obesity
Peripheral edema -
Atlanto-axial subluxation
DDx -
RA
Trauma
DownÂ’s'
MorquioÂ’'s -
Short 4th metacarpal
DDx -
Idiopathic
PseudoHPT
PseudopseudoHPT
Turner's
Basal cell nevus syndr (mandibular cysts, dural Ca++) - Widened teardrop in hip DDx
-
- Infection
- Trauma
- PVNS (erosions, preserved jt space)
- Synovial osteochondromatosis
- AVN - MRI characteristics of PVNS
-
Villous or lobulated masses
T1 - INT to HI
T2 - INT to HI
Effusion
Capsulosynovial thickening - MRI characteristics of synovial chondromatosis
-
Well defined rounded masses
T1 - LO
T2 - LO
Effusion
Capsulosynovial thickening - MRI characteristics of lipoma arborescens
-
Villous or lobulated masses
T1 - HI
T2 - LO
Effusion
Capsulosynovial thickening -
DDx
Skeletal MRI shows bright ring with dark center -
Common
- Osteoid osteoma
- Bone infarct
- Osteochonditis dissecans
- AVN
Uncommon
- Brodie's abscess
- EG
- Melanoma mets -
Soft tissue mass on MRI
T2 bright with dark center -
Neurofibroma
Sarcoidosis
Acute hematoma -
Soft tissue mass on MRI
moderate to marked T1 bright -
Lipoma
Hematoma
Well-diff liposarcoma
Myxoid liposarc or myxosarc -
Soft tissue mass on MRI
Homogeneously T1 dark -
Cyst
Ganglion
Lymphocele
Hygroma
Seroma -
Soft tissue mass on MRI
mildly T1 bright rel. to muscle -
Neurilemmoma or neurofibroma
Hemangioma
Abscess
Solid malignancy (sarc or carci)
Hemorrhagic mass - DDx for lipohemarthrosis of the knee
-
* tibial plateau fracture
* ACL avulsion fracture
* patellar dislocation w/ osteochondral injury - Arthritis affecting the DIPs
-
Psoriatic Arthritis
Osteoarthritis
Erosive osteoarthritis
Multicentric reticulohistiocytosis - Arthritis with Periostitis
-
Juvenile Rheumatoid Arthritis
Infectious arthritis
Reiter’s syndrome
Psoriatic Arthritis