Exam 3: Benign Tumors (Part 1)

Giant Cell Tumor (GCT)

-neoplasm that originates from non-bone forming supportive connective tissue of the marrow

-aka osteoclastoma

-80% benign and 20% are malignant

-quasi-malignant

-male to female ratio = 1:1

What is the common age of occurrence for a GCT?

20-40 years old

Osseous locations of a GCT:

-MC found in the knee

-85% in long bones (distal femur and proximal tibia = 50-60%, distal radius and proximal humerus)

-15% in flat bones (pelvis, sacrum near SI, spine, ribs, skull)

GCT is the most common benign tumor of the _____

sacrum

GCT lesions of distal ____ have a higher chance of being malignant

radius

Signs and symptoms of a GCT:

-localized pain of an aching nature

-restricted joint motion

-malignant variety female to male = 1:3

Radiographic features of a GCT:

-geographic

-eccentric

-metaphyseal-epiphyseal

-SUBARTICULAR

-expansion/soap bubble/or purely lytic

-cortical thinning

Treatment and prognosis of GCT:

-surgical curettage and with liquid nitrogen freezing, bone packing or grafting the recurrence rate is 12-50%

-radiation often for spinal lesions

-5 year survival for malignant lesions in 10% of cases

Solitary Osteochondroma

-bone exostosis on the external surface of a bone and usually lined up by a hyaline cartilage cap

-MC benign osseous tumor

-represents 50% of all benign bone tumors

-unknown cause, displaced cartilage from the physis

What is the typical age of occurrent for a solitary osteochondroma?

Clinical features of a 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

Solitary osteochondromas typically with malignantly transform into a:

chondrosarcoma

Sessile solitary osteochondroma:

-broad base and no stalk

-common in the humerus and scapula

Pedunculated solitary osteochondroma:

-long stalk with cartilage cap

-common in knee, hip and ankle

-"coat hanger exostosis"

-"cauliflower cap"

-stalk points AWAY from nearest joint

Osseous locations of a solitary osteochondroma:

-metaphysis of long bones (femur and tibia, humerus and proximal radius)

-flat bones (scapula, ribs, pelvis, and spine)

-any bone formed by enchondral ossification

Radiographic features of a solitary osteochondroma:

-metaphyseal bony exostosis

-pedunculated and sessile

-may appear as a dense corticla rim around an area of lucency

-sessile lesion may cause metaphyseal widening or appear as an asymmetrical bump

-malignant degeneration 1% for siltary and 20% for HME

The growth of a solitary osteochondroma stops when the ____ closes, and if growth continues it could lead to potential malignant degeneration

growth plate

Radiographic appearance of a solitary osteochondroma:

-cortex and spongiosum blend imperceptibly with the host bone

-growth is at an angle to the long axis and toward the midshaft

-widespread presentation usually has a familial history (hereditary multiple exostosis (HME))

Hereditary Multiple Exostosis (HME)

-aka diaphyseal achalasia

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

HME most commonly occurs in what age group?

2-10 years of age; male to female ratio = 2:1

Clinical features of HME:

-number from a few to a hundred with an average of 10

-presents as multiple painless hard masses around joints

-cord compression or obstructive uropathy are possible

-malignant transformation in 5-20%

HME most commonly malignantly transforms in a:

chondrosarcoma

Radiographic features of HME:

-cortex and spongiosum contiguous with host bone

-shortening of the 4th and 5th metacarpals

-supernumerary fingers and toes

-madelung or bayonet deformity

-disproportionate shortening of extremity

Madelung or Bayonet Deformity

impaired bone growth, short ulna, bowing of radius and subluxation of radioulnar joint; present in HME

Osseous locations of HME:

-metaphysis of long bones (knees, shoulders, ankles, hips, wrists)

-flat bones (pelvis, ribs, and scapula)

Simple/Solitary/Unicameral Bone Cyst (SBC)

-non neoplastic fluid filled cystic cavity lined with fibrous tissue

-represent 3% of primary bone tumors

SBCs typically occur in what age range?

3-14 years of age; male to female ratio = 2:1

Clinical features and locations of SBC:

-asymptomatic unless fractured

-60-75% occur in proximal humerus and femur, fibula, calcaneal neck and talus

-may be active or latent

Radiographic features of a SBC:

-metaphyseal adjacent to growth plate

-central, 2-3 cm oval radiolucency with long axis parallel to host bone

-may be lobulated with endosteal scalloping

-truncated cone appearance

-fallen fragment appearance if fractured

Treatment and prognosis of a SBC:

-spontaneous regression in some

-surgical curettage and bone chip

-most effective treatment is the injection of steroids

Aneurysmal Bone Cyst (ABC)

-non neoplastic expansile lesion containing thin-walled blood-filled cystic cavities

-is named for radiographic appearance

-channels of flowing blood

-proliferation of the vascular component of the marrow

-primary (MC) or secondary to another lesion

-60% occur in females

What is the age of occurrence for an ABC?

10-30 years old; 75% occur below the age of 20

Clinical features of an ABC:

-LOTS of pain

-positive history of trauma

-neurologic signs with spinal involvement

-frequent pathologic fractures due to being VERY expansile and thinning cortex extensively

ABC locations:

-spine (30%) especially the neural arch

-long bones (metaphysis of femur, tibia, fibula and humerus)

-flat bones

Radiographic features of an ABC:

-purely lytic and eccentric

-METAPHYSEAL

-aggressive expansile ballooning lesion (soap bubble)

-rapid progression in 6 weeks to 3 months

-almost invisible thin cortex

-can cause missing pedicle

Advanced imaging findings of an ABC:

-increased uptake on bone scan

-CT shows fluid-fluid levels due to blood layering and identification of cortex

-MRI shows multiple cysts of different signal intensity representing different stages of blood byproducts

Osteoblastoma

-rare benign bone tumor with unlimited growth potential

-resembles osteoid osteoma but larger

-male to female ratio = 2:1

Age of occurrence for an osteoblastoma:

10-20 years old

Clinical features of osteoblastoma:

-asymptomatic in

Osteoblastoma locations:

-spine (40%) particularly involving the posterior neural arch structures

-long bones (30%) femur, tibia, humerus, radius and fibula

-small bones of the hands in feet (25%)

Radiographic features of an osteoblastoma:

-spinal lesions are usually radiolucent and expansile

-long bones show a progressive expansile lesion that may rapidly increase in size

-positive matrix calcification

Treatment and prognosis of an osteoblastoma:

-small lesions are treated by excision or curettage

-recurrence rate of 5%

-spinal lesions often undergo radiation