di imaging II exam 3 benign tumors

giant cell tumor (also called an osteoclastoma)

neoplasm that originates from non-bone forming supportive connective tissue of the marrow - 80% are benign and 20% are malignant - age of occurence is 20-40 years - M:F is 1:1

osseous location of giant cell tumor

85% in long bones (distal femur and proximal tibia 50-60%, distal radius, and proximal humerus), 15% in flat bones (pelvis, sacrum near SIJ, spine 5%, rib and skull), lesions of distal radius higher chance of being malignant

what is the most common benign tumor of the sacrum?

giant cell tumor

clinical presentation of giant cell tumor

localized pain (!) of an aching nature, restricted joint motion - malignant variety female to male 1:3

radiographic findings for giant cell tumor

geographic, eccentric, metaphyseal-epiphyseal (extend to the end of the bone), subarticular, expansion/soap bubble/or purely lytic, cortical thinning, short zone of transition

giant cell tumor treatment and prognosis

surgical curettage and with liquid nitrogen freezing, bone packing, or grafting (recurrence rate of 12-50%) - radiation often for spinal lesions - 5 year survival for malignant lesions is 10%

solitary osteochondroma

bone exostosis on the external surface of a bone and usually lined by a hyaline cartilage cap - the most common benign osseous tumor (50% of all benign bone tumors) - unknown cause, displaced cartilage from the physis - seen in those under 20 years old with M:F is 2:1

clinical features of solitary osteochondroma

most are asymptomatic, unless they disturb surrounding nerves or vessels, complaints of a painless hard mass, pain from a fractured stalk or cord compression with spinal lesions, obstructive uropathy from pelvic tumor, pain and new growth may indicate malignant transformation

sessile solitary osteochondroma

has a broad base and no stalk, common in the humerus and scapula

pedunculated solitary osteochondroma

has a long stalk with a cartilage cap, common in knee, hip, and ankle - coat hanger exostosis, cauliflower cap

location for solitary osteochondroma

metaphysis of long bones (femur and tibia 50%, humerus, proximal radius), flat bones (scapula, ribs, pelvis, spine 1-5%), any bone formed by enchondral ossification

radiographic features of solitary osteochondroma

metaphyseal bone exostosis, peduculated and/or sessile, en face may appear as a dense cortical rim around an area of lucency, sessile lesion may cause metaphyseal widening or appear as an asymmetrical bump, growth stops when growth plates close (if it’s still growing, think malignancy), malignant degeneration 1%

radiographic appearance of solitary osteochondroma

cortex and spongiosa blend imperceptibly with the host bone, growth is at an angle to the long axis and towards the midshaft (project away from the joint - coat hanger exostosis), if multiple are present and it’s widespread, usually there’s a family history and is hereditary multiple exostosis

hereditary multiple exostosis (diaphyseal achalasia)

an inherited autosomal dominant condition which is characterized by multiple osteochondromas often causing metaphyseal overgrowth

hereditary multiple exostosis clinical features

discovered between 2-10 years of age with a M:F of 2:1 - number from a few to a hundred with an average of 10 - presents as multiple painless hard masses about the joints - cord compression or obstructive uropathy are possible - malignant transformation ~5-20% most into chondrosarcomas (pain and renewed growth)

hereditary multiple exostosis radiographic features

cortex and spongiosa contiguous with host bone - shortening of the 4th and 5th metacarpals - supernumerary fingers and toes - madelung or bayonet deformity (these can occur without HME though too) - disproportionate shortening of extremity

hereditary multiple exostosis locations

metaphysis of long bones (multiple and bilateral), knees, shoulders, ankles, hips, wrists - if in flat bones then pelvis, ribs, and scapula

madelung deformity

impaired bone growth, short ulna, bowing of radius and subluxation of the radioulnar joint

simple/solitary bone cyst

a non-neoplastic fluid filled cystic cavity lined with fibrous tissue - usually occurs around 3-14 years (80% of the time) - M:F is 2:1 - represents ~3% of primary bone tumors - asymptomatic unless fractured (so if they hurt, then it’s either not this or something’s wrong with it = pathological fracture)

solitary bone cyst locations

60-75% occur in proximal humerus and femur, fibula, calcaneal neck, talus - may be active (maintain growth potential) or latent (displaced from growth plate by normal bone growth)

radiographic features of solitary bone cysts

metaphyseal adjacent to growth plate - central, 2-3cm oval radiolucency with long axis parallel to host bone that may have thin septa (horizontal radiolucent lines) with endosteal scalloping - truncated cone appearance and produces fallen fragment sign if fractured

solitary bone cyst treatment and prognosis

spontaneous regression in some - surgical curettage and bone chip but recurrence rate of 30-40% - most effective treatment is the injection of steroids

aneurysmal bone cyst

non-neoplastic expansile lesion containing thin-walled blood-filled cystic cavities - is named for its radiographic appearance - has channels of flowing blood and proliferation of vascular component of the marrow - age of occurrence is 20-30 years but 75% occur below age 20 - more common in females (60%) - most common to be a primary lesion but may be secondary to something else - could be a reason for a missing pedicle

clinical features of aneurysmal bone cysts

acute onset of (a lot) pain with rapid increase in severity over 6-12 weeks - might have a history of trauma, might not - neurologic signs (radiculopathy or quadriplegia) with spinal involvement - frequent pathological fractures

locations for aneurysmal bone cysts

spine in 30% of cases (likes posterior elements like SP, lamina, pedicle, TPs), long bones (metaphysis of femur, tibia, fibula, humerus), flat bones would be pelvis

radiographic features of aneurysmal bone cysts

purely lytic and eccentric, metaphysis (small bones may appear central) - aggressively expansile ballooning lesion ‘soap bubble’ - rapid progression in 6 weeks-3 months - almost invisible thin cortex

advanced imaging findings for aneurysmal bone cyst

increased uptake on a bone scan - CT will have fluid-fluid levels due to blood layering and identification of cortex - MRI shows multiple cysts of different signal intensity representing different stages of blood by-products (blood degradation)

treatment and prognosis for aneurysmal bone cysts

surgical curettage and bone chip therapy with possible recurrence at ~50% - radiation therapy may be used for some lesions especially in the spine

osteoblastoma

a rare benign bone tumor with unlimited growth potential with peak age occurrence being 10-20 years (70% of cases) and M:F of 2:1 - resembles osteoid osteoma but larger than 2cm (giant osteoid osteoma)

clinical features of osteoblastoma

rarely asymptomatic, more likely to see dull pain of insidious onset (84%), worse at night in 7-13% that’s not relieved by aspirin - localized swelling and tenderness, decreased ROM, painful scoliosis in 50% of cases

osteoblastoma locations

spine in ~40% particularly involving the posterior neural arch structures - long bone involvement is ~30% with femur, tibia, humerus, radius, fibula - small bones of the hands and feet ~25%

radiographic features of osteoblastoma

spinal lesions are usually more dense and expansile - long bones show a progressive expansile lesion that may rapidly increase in size in 25% metaphyseal to diaphyseal - positive or negative matrix calcification (osteoid matrix)

treatment and prognosis of osteoblastoma

small lesions are treated by excision or curettage with a recurrence rate of 5% - spinal lesions often undergo radiation

osteoid osteoma

a benign skeletal neoplasm composed of osteoid and woven bone less than 1.5cm in diameter - represents 12% of benign bone tumors and occurs between 10-15 years of age with M:F of 2:1

clinical features of osteoid osteoma

tender to touch and pressure - local pain 95-98% that’s lasted for weeks to years in duration, worse at night, decreased by activity - slaicylates give relief in 20-30 minutes in 75-90% of cases

osteoid osteoma locations

meta/diaphysis of long bones in 73% of cases in proximal femur, proximal tibia, humerus - 14% in spine, predominantly the posterior elements of lower thoracic and upper lumbars creating a painful scoliosis (concave) - no bone is exempt

radiographic features of osteoid osteoma

the lesion is the radiolucent nidus (where the tumor lives) usually <1cm with reactive sclerosis (due to irritation from the tumor) - a cortical one will have nidus in cortex, fusiform cortical thickening with 1cm radiolucent area - in cancellous bone, may be difficult to identify with delay in diagnosis 4 months-5 years due to little reactive sclerosis

treatment and prognosis for osteoid osteoma

complete surgical excision of the nidus (reactive bone sclerosis regresses subsequently) with little chance of recurrence - vertebral body lesions may be irradiated - percutaenous radiofrequency ablation is the preferred treatment option - will resolve spontaneously in ~33 months so you could leave it alone

osteoid osteoma advanced imaging findings

intense uptake on bone scan (double density sign) - CT used for precise detection and localization of the nidus - angiography shows highly vascularized nidus with intense circumscribed blush appearing in early arterial phase

osteoma

benign tumor arising in membranous bone commonly found in adulthood - well circumscribed round extremely dense lesion ~2cm in size - mostly asymptomatic - associated with gardner’s syndrome

gardner’s syndrome

multiple osteomas, colonic polyposis, and soft tissue fibromas

osteoma location

para-nasal sinuses (frontal and ethmoid), inner/outer table of the calvarium (usually the external table), occasionally mandible or nasal bones

enchondroma

benign cartilaginous growth in the medullary cavity of bones preformed in cartilage - arise in residual islands of cartilage left behind - 10-30 years and 1:1 M:F - usually asymptomatic - pathologic fracture may occur

what’s the most common benign tumor of the hand

enchondroma

locations for enchondromas

40% occur in small bones of the wrists and hands (proximal phalanges more likely than metacarpals), femur, tibia, humerus, radius, ulna, feet, ribs (long bones), usually central and meta/diaphyseal

radiographic features of enchondromas

round/oval lucency with fine marginal line - central is most common - endosteal scalloping, stippled or punctate calcifications, possible cortical thinning and expansion

treatment and prognosis for enchondromas

usually require no treatment - symptomatic lesion in long bones may require surgical curettage and bone chips - malignant degeneration ~1%, but percentage increases the closer to the axial skeleton it occurs

enchondromatosis/ollier’s disease

non-hereditary failure of cartilage ossification - early childhood presentation with hand and feet deformity and multiple enchondromas - ~10% malignant degeneration rate - maffucci syndrome

maffucci syndrome

multiple soft tissue hemangiomas seen with enchondromatosis (looks like phleboliths but not where they should be) - percentage of malignant change increases with these

hemangioma

usually solitary vascular neoplasm which is slow growing and composed of newly formed capillary, cavernous, or venous blood vessels - occurs commonly in 30-40a with M:F of 1:2 - most common benign tumor of the spine - usually asymptomatic

what advanced imaging should be done if there are symptomatic hemangiomas?

MRI to see if spinal lesion expansion is causing spinal stenosis and cord compression

locations of hemangiomas

vertebral body in the lower thoracics/upper lumbars - calvarium with preference for frontal bone

radiographic spinal features of hemangiomas

exaggerated vertical trabeculations (accordion, corduroy, honeycomb) at singular vertebra - posterior bulge of cortex - extra-osseous extension beyond bony lesion causing cord compression - paravertebral soft-tissue extension - polka-dot appearance on CT

radiographic skull features of hemangiomas

<4cm round lytic lesion with sunburst or spoked-wheel appearance viewed en face - may occur in diploic space producing a palpable lump secondary to widening of the space - often will remove these

treatment and prognosis for hemangiomas

usually asymptomatic so usually require no treatment - symptomatic spinal lesions may undergo decompression surgery and need an MRI - symptomatic skull lesion often treated with en bloc excision

chondroblastoma

rare benign bone tumor usually happening around 8-59 years with a peak incidence between 5-25 (85%) - occurs before the cessation of enchondral bone growth and M:F of 2:1

clinical features of chondroblastoma

often symptomatic (HURTS) for months to years prior to treatment - mild joint pain, tenderness, joint swelling, and limitation of motion

chondroblastoma locations

develops around an apophysis or epiphysis in a subarticular location - 2/3 found in lower extremities = proximal femur, distal femur, proximal tibia, proximal humerus, tarsal bones

radiographic features of chondroblastoma

round or oval eccentric lytic lesion of an epiphysis or apophysis 1-6cm in diameter - well defined slcerotic margin - lobulated in 50%, irregular/punctate calcification in 25-50%, periostitis along metaphysis in 30-50%

treatment and prognosis of chondroblastoma

surgical curettage and packing with bone chips with local recurrence rate of 20% - resection in an expendable area might be needed

fibrous cortical defect

most common 2-8 years (peak 7-8), affects 30% of children - fibrous cell rests - asymptomatic and under 2cm

the WHO lumps what 2 things together and calls them fibrous xanthomas?

fibrous cortical defect and non-ossifying fibroma

fibrous cortical defect locations

metaphyseal cortex of long bones of the lower extremity (posterior-medial surface of the distal femur, tibia, fibula, and proximal femur) - other less common places are ilium, ribs, or proximal humerus

radiographic features of fibrous cortical defect

round lytic lesion 1-2 cm in diameter with a well-defined sclerotic margin - eccentric and metaphyseal - oval and extending parallel to the long axis which could produce cortical thinning and expansion - lytic or bubbly in appearance with a sclerotic border - may be multilocular - should NOT hurt

treatment and prognosis of fibrous cortical defect

no treatment necessary as these lesions tend to spontaneously regress over 2-5 year period

nonossifying fibroma

most common in 8-20 year olds with 75% occurring in teenage years, affects 30% of children - asymptomatic - larger than 2cm

nonossifying fibroma locations

effects long bones of lower extremity like distal tibia, distal femur, proximal tibia, fibula and occasionally proximal humerus - eccentric and metadiaphyseal

nonossifying fibroma radiographic features

eccentric multilocular void lesion along the long axis - lytic lesion ~2cm or more in length with dense sclerotic border - endosteal scalloping and thinning (may see bulging may not) - migrates toward diaphysis

treatment and prognosis for nonossifying fibroma

no treatment rendered as these lesions spontaneously regress with age in most cases and are not painful - large lesions >8cm may require curettage and bone packing to prohibit fracture

paget’s disease

tumor like process affecting 3% of those over 40 years (UK, Aus, NZ) - bone lysis/resorption followed by extensive repair/bone formation attempts - newly formed bone has disorganized trabecular pattern lending to bone softening - most are asymptomatic but sometimes bones can get bigger (bad for bones with foramens in them) - bisphosphonates or calcitonin given to inhibit bone resorption and bone loss

clinical info for paget’s disease

most are over 55 years with M:F of 2:1 - 12% have a 1st degree relative with paget’s - thought to be viral etiology now but likely to have some genetic component - bone pain is most common symptom - secondary arthritis, bony deformity (bowing of an extremity is most common) -excessive warmth from hypervascularity - neurologic complications caused by compression of neural tissues - cardiac issues

locations of paget’s disease

usually polyostotic (multiple sites) and asymmetric - pelvis, lumbar spine, thoracic spine, proximal femur, calvarium, scapula, distal femur, proximal tibia, proximal humerus

laboratory findings of paget’s disease

need bone scan and orthopedist consult - increased hydroxyproline, increase alkaline phosphatase, but normal serum calcium and phosphorus

stages of paget’s disease

stage 1: osteolytic/destructive

stage 2: mixed/combined

stage 3: sclerotic/ivory

stage 4: malignant degeneration 0.9-2% (transforms into a sarcoma)

radiological features of paget’s disease

increased or decreased density (or mixed), coarsened irregular trabecular pattern, thickened cortex (internal and external), bone expansion, subarticular to diaphysis, osseous deformity (bone softening pathology), pathologic fractures

skull features of paget’s disease

osteoporosis circumscripta (well defined/circumscribed geographic lysis (map like) of the frontal and occipital regions) - cotton wool appearance (fuzzy, poorly defined areas of increased density in the skull) - basilar invagination with foraminal encroachment

what should we be looking for when there is paget’s in the skull and what lines do we use?

atlantoaxial impaction - chamberlain’s line and mcgregor’s line

long bone features of paget’s disease

begins at the subarticular area (bone end) - ‘candle flame/blade of grass sign’ (advancing edge of the lytic change) - cortical thickening and irregular disorganized trabeculae - bowing deformities (shepherd’s crook)

banana fracture

tiny horizontal cortical infractions (looser lines) on convex surfaces of lower extremity represent insufficiency fractures - seen with paget’s

pelvic features of paget’s disease

thickening of iliopectineal line and cortical lines of the pubic bones = rim sign/brim sign - cortical thickening and widened pubic bones - thickening and disorganization of trabeculae - acetabular protrusion

spinal features of paget’s disease

coarse vertical trabeculae - thickened endplates and enlarged vertebral body - picture frame vertebra, ivory vertebra - pathological collapse

possible complications of paget’s disease

peripheral nerve compression - brainstem compression and spinal stenosis (basilar invagination) - hearing loss, blindness, facial palsy, hyperemia of overlying skin - deformities (shepherd’s crook for femur, sabre shin for tibia) - ‘banana fracture in long bones (pseudofractures, ‘looser lines’) - pathologic fractures - high output cardiac failure - degenerative joint disease - 1-2% malignant transformation

what kind of fractures are banana fractures?

insufficiency fractures

fibrous dysplasia

benign fibro-osseous developmental anomaly, of the mesenchymal precursor of bone, manifested as a defect in osteoblastic differentiation and maturation - occurs in first and second decades of life with M:F of 1:1 and unknown etiology

monostotic form of fibrous dysplasia

more common form 70-80% of cases - affects ribs, proximal femur, and craniofacial bones

polyostotoic form of fibrous dysplasia

20-30% of cases and has unilateral and asymmetric long bone involvement - femur > tibia > pelvis > feet > ribs > skulls and facial bones > upper extremities and spine - seen with endocrine abnormalities

signs and symptoms of fibrous dysplasia

usually dependent on type of disease and extent, but many are asymptomatic while other may have pain secondary to deformity/fracture

McCune Albright Syndrome

polyostotic fibrous dysplasia with cafe au lait spots - endocrine dysfunction precocious puberty in females 20% of the time

radiological features of fibrous dysplasia

most medullary cavity lesions are lucent, loculated, or trabeculated with a thick rim of sclerosis ‘rind sign’ - may cause thinning of the cortex and widening of the shaft (go to orthopedist whenever cortex has been thinned) - internal matrix is usually cloudy and gives ‘ground glass appearance’

skull radiographic features of fibrous dysplasia

often areas of increased density along the convexity and anterior fossa - unilateral overgrowth of the fascial bones - expansion in skull bones and ribs

possible complications of fibrous dysplasia

leg length discrepancy, shepherd’s crook and sabre shin deformities, cranial nerve compromise, protrusio acetabuli, proptosis (bulging eyes), pseudoarthrosis of the tibia in infancy, malignant transformation 0.5-1% of the time, pathologic fractures