Lecture 4 Benign Osseous Neoplasms

What are the only pediatric tumors that are characteristically in the epiphysis?

-Chondroblastoma

What are almost always abutting an articular surface, don’t have a sclerotic margin, and are in middle-aged individuals?

-Giant Cell tumor

Giant Cell Tumor

-AKA Osteoclastoma

-Quasi malignant (80% benign, 5-8% of primary malignancies, 15% of benign osseous neoplasms)

-Most common at 20 to 40 years of age

Giant Cell common locations

-Knee (most common)

-Distal radius

-Proximal humerus

-Sacrum

Imaging Feature of Giant Cell Tumor

-Geographic lytic lesion eccentrically located within the metaphysis about the knee, without a sclerotic margin

-In long bone 90% will have subarticular extension

-80 to 90% will not show sclerotic margin

-Multiloculate and septated

-Expansile

-Imaging cannot differentiate malignant from benign

What is indicated by fluid-fluid levels on advanced imaging?

-Aneurysmal bone cyst

Giant Cell Tumor on X-ray

Osteochondroma

-Most common benign skeletal tumor

-75% develop before the age of 20

-Males more commonly affected

-2 types pedunculated & sessile

Clinical Presentation of Osteochondroma

-Most asymptomatic and found incidentally

-Painless hard mass

-Pedunculated may fracture

-May cause compression and irritation on adjacent structures

-Pain and rapid growth suggest malignant degeneration

Cartilaginous cap over how much is concerning for malignant degeneration in osteochondroma?

-Over 1.5 cm

Most common area for Osteochondroma?

-Knee and the humerus

-Adjacent to growth plates and pointing away from articulations

Imaging Features of Osteochondroma

-Corticomedullary continuity

-Pedunculated (thin stalk with large distal cap that is covered in hyaline cartilage)

-Sessile (Broad based osseous excrescence with possible overlying cartilaginous cap)

-Potential sign of accommodation of adjacent osseous structures or signs of soft tissue irritation

Pedunculated Osteochondroma on X-ray

Sessile Osteochondroma on X-ray

Sessile Osteochondroma in Knee on X-ray

Hereditary Multiple Exostoses

-AKA osteochondromatosis

-Multiple osteochondromas that may cause severe boney deformity

-80% discovered by 10 years of age

Clinical Presentation of Hereditary Multiple Exostoses

-5 to 25% malignant degeneration

-Possible symptoms associated with deformity

Distribution of Hereditary Multiple Exostoses

-Knee

-Ankle

-Shoulder

-Hip

-Wrist (madelung-like deformity)

HME on X-ray

Brahma Bull Appears (HME) on X-ray

Madelung-like Deformity on X-ray (HME)

Hemangioma

-Solitary Vascular Neoplasm

-Slow growing

-Most common benign tumor of the spine

-Most common in over 40 years old & females

-2 types cavernous (spine & skull) & Capillary (Ribs, pelvis, metaphyses of long bones)

Clinical Presentation of Hemangioma

-Most are asymptomatic

-Rarely locally aggressive

-Expansion rarely results in neurologic symptoms

Most common location of Hemangiomas

-75% are in the spin and skull

Hemangioma Radiograph Features

-Vertically striated vertebra (Jail bar aka corduroy cloth appearance)

-Lace-like trabeculae in long bones

-Sand dollar, sunburst, or spoke wheel appearance in skull

Hemangiomas on MRI are?>

-High signal on both T1 and T2 due to high fat content

Hemangioma on X-ray (sunburst/sandollar)

Hemangioma in Finger on X-ray

Osteoma

-Exophytic osseous neoplasm

-Usually solitary and in sinuses (Frontal > Ethmoid > Maxillary > Sphenoid)

-Rarely outside of skull

Clinical Presentation of Osteoma

-Most are asymptomatic but can cause chronic sinusitis when obstructing sinus drainage

-Associated with Gardener’s Syndrome (multiple osteomas, Familial adenomatous polyposis, dental abnormalities)

Osteoma on X-ray

Enostoma

-AKA bone island

-Hamartoma of bone

-Essentially an osteoma within the medullary canal

-Any age but adults are more common than children

-Usually solitary and asymptomatic

Distribution of Enostoma

-Long bones (epiphyseal and metaphyseal)

-Medullary

-Ischium

-Ilium

-Sacrum

Imaging Features of Enostoma

-Well defined purely sclerotic lesion that is typically <1cm and shows a ‘brush border’ margin

-Round or oval

-Long axis aligned with the weight bearing trabeculae

-May change size

-Occasionally warm on bone scan

Enostoma on X-ray

Osteoid Osteoma

-In patients 10 to 25 years of age (males more common)

-Cortically based osseous lesion that is highly vascularized and secretes prostaglandins

-Treated with excision or radiofrequency ablation

Classic presentation of Osteoid Osteoma

-Severe pain, worse at night, relieved by aspirin

DDX of Osteoid Osteoma

-Osteoblastoma (based on size)

-Brodie abscess

-Fatigue fracture

Distribution of Osteoid Osteoma

-50% in femur and tibia

-20% hand/feet

-10% spine (neural arch)

Imaging Feature of Osteoid Osteoma

-Central lucent nidus with surrounding sclerosis and solid periosteal reaction

-Cortically based

-Central calcific fleck

-One of the few neoplasms that is better visualized on CT than MRI

Osteoid Osteoma on X-ray

Osteoid Osteoma in the Spine on CT

10% of Osteoid Osteoma will show what?

-Painful scoliosis with lesion at the apex on the concave side

DDX for poorly visualized lesions of Osteoid Osteoma are?

-Fatigue stress fracture and intracortical abscess

Osteoblastoma

-Histologically identical to osteoid osteoma (a giant osteoid osteoma)

-Rare

-Peak age of 10 to 20 years old

-Males more common in

Clinical presentation of Osteoblastoma

-Pain (less severe than OO)
-not nocturnal
-Not relieved by aspirin

-50% of spinal will have a painful scoliosis

-Possible spinal stenosis

Distribution of Osteoblastoma

-Spine 35-50% (posterior elements, thoracolumbar, lower cervical)

-Long bones 30% (metaphysis > diaphysis; lower extremity)

-Hands/feet (dorsal talus; carpal/tarsals)

Osteoblastoma in the spine on Imaging

-Expansile lesion of neural arch

-4-6cm

-thinned cortex

-mostly lucent

-DDX ABC and GCT

Osteoblastoma in the Extremities on imgaing

-Lytic and expansile

-Sparing of the epiphysis

-Lucent nidus >2cm

-Limited peripheral sclerotic reaction

Osteoblastoma on X-ray

What is the most common painless tumor in the hands and feet?

-Enchondroma

Enchondroma

-Most common benign tumor of the hands and feet

-age between 10 to 30 years of age

Enchondroma clinical presentation

-Painless unless complications are present (fracture & malignant degeneration)

Enchondroma clinical Distribution

-Small tubular bones of hands and feet (proximal phalanx is the most common)

-Large tubular bones (femur, tibia, humerus)

Enchondroma Imaging features

-Central geographic lesion in any part of the tubular bone (hands & feet)

-Long bones will have ICE lesion

-Endosteal scalloping <2/3 the width of the cortex (in large bones)

-Stippled calcification 50%

-MRI shows marked hyperintensity on T2 due to high water content in cartilage

Enchondroma on X-ray

Enchondroma on X-ray (knee)

Enchondroma Malignant degeneration on X-ray

Enchondromatosis

-AKA Ollier’s disease

-Uncommon

-Multiple enchondromas that can be very large and cause severe deformity

-Chance of malignant transformation 10-50%

Enchondromatosis on X-ray

Enchondromatosis on X-ray (not in hands)

Maffucci Syndrome

-Rare

-Multiple enchondromas with soft tissue hemangiomas

-Malignant transformation in 25 to 50%

Maffucci Syndrome on X-ray

Chondroblastoma

-AKA Codman’s Tumor

-Uncommon chondral tumor

-Peak incidence in 10 to 25 years of age

-More common in males

-Begin to form before physeal closure

Lytic patellar lesion should be what?

-Chondroblastoma

-Enchondroma

-Giant Cell Tumor

Clinical Presentation of Chondroblastoma

-Pain and tenderness

-Possible soft tissue swelling

-Joint effusion

Distribution of Chondroblastoma

-90% medullary

-Located in the apophyses and epiphyses of long bones

Imaging features of Chondroblastoma

-3 to 6 cm geographic lytic lesion in the apophysis or epiphysis of a long bone in a young patient

-30% show solid or laminated periosteal reaction

-30% show joint effusion

-50% show internal calcification

Chondroblastoma on X-ray

Non-Ossifying Fibroma/Fibrous Cortical Defect

-Very common fibrous lesion

-Males more affected

-30 to 40% of asymptomatic children

FCD age?

-4 to 8

NOF age?

-8-20

Fibroxanthoma age?

-over 20

Clinical Presentation of NOF/FCD

-Typically asymptomatic unless pathologic fracture occurs

-No malignant transformation

-Heals with sclerosis and progressive involution

Distribution of NOF/FCD

-Ankle and knee are common

NOF/FCD Imaging Features

-Called a ‘blister of bone’ because of eccentric, mildly expansile appearance

-Geographic lytic lesion with fibrous “ground glass” matrix

-Multiloculated (soap bubble appearance)

NOF/FCD on X-ray

Simple Bone Cysts is almost always in the?

-Proximal humerus

-Proximal femur

Simple Bone Cyst

-AKA unicameral bone cyst

-Not a true neoplasm

-Peak incidence at 3 to 14 years of age

-More common in males

Clinical Presentation of Simple Bone Cyst

-Asymptomatic until fracture (2/3 present with fracture)

-30 to 40 % reoccur after resection

-No malignant potential

Imaging Features of Simple Bone Cyst

-Centrally located, mildly expansile, unilocular, geographic lytic lesion in the proximal humerus or femur

-Fracture shows fallen fragment sign

Fallen Fragment Sign on X-ray

Simple Bone Cyst on X-ray

Aneurysmal Bone Cyst

-Peak incidence in 5 to 20 (80% being less than 18)

-More common in females

-Often seen as a secondary lesion in other primary neoplasms/neoplasm-like processes (GCT, Chondroblastoma, Osteoblastoma, Osteosarcoma, NOF)

Clinical Presentation of Aneurysmal bone cyst

-Acute pain and swelling

-Often post traumatic or post surgical

-Common in neural arch, resembling an osteoblastoma, so pain and signs of stenosis may be present

Distribution of Aneurysmal Bone Cyst

-80% in tubular bones and spine/pelvis

-Most common benign lesion of clavicle

-Eccentric and within metaphysis/diaphysis

Most common benign lesion in clavicle?

-Aneurysmal Bone cyst

Imaging Feature of Aneurysmal Bone Cyst

-Rapidly expansile, eccentric, soap bubbly, lytic lesion in a young patient

-Often shows fluid-fluid levels on MRI

-Possible periosteal buttressing (may look like codman’s triangle)

-Saccular ballooning of cortex

ABC on X-ray

Cortical buttressing (ABC) on X-ray

Intraosseous Lipoma

-Most common soft tissue tumor but uncommon in bone

-age ranges are 5 to 70 years old

Clinical Presentation of Intraosseous Lipoma

-Aching Pain 70%

-Asymptomatic 30%

What is the most common calcaneal bone lesion?

-Intraosseous Lipoma

Imaging Features of Intraosseous Lipoma

-Geographic lucency that may have a central calcification called a cockade sign

Intraosseous Lipoma on X-ray