Skeletal Malignancies and Bone Tumors

Question 1

Osteoid Osteoma

Answer 1

• Benign
• 3:1 male female
• Cortical bone of long bones
• Insidious onset of pain (usually nocturnal), gait disturbance, muscle wasting, scoliosis
• If intra-articular, may have joint swelling and limited ROM mimicking arthritis
• NSAIDS work better than Tylenol

Question 2

Osteoblastoma

Answer 2

• Benign
• Older children
• Predilection for medullary bone
• Bigger than osteoid osteoma

Question 3

Giant cell tumor

Answer 3

• Benign but locally aggressive
• Adolescent females
• Pain, swelling, limited ROM
• Ephiphyses of long bones most common site
• May have pathologic fracture
• Usually solitary ( rarely multi centric)
• XR shows expansile, eccentrically placed lytic area resulting from intra tumoral hemorrhage, usually involving ephiphysis and adjacent metaphysis
• MRI can show expansile hypervascular mass with cystic changes and large amounts of hemosiderin

Question 4

Osteochrondroma

Answer 4

• Benign
• Cartilage capped bony projections
• usually metaphyseal
• Can have a family history
• 15% have multiple lesions
• Usually asymptomatic but can have painless mass, significant growth deformity, symptoms of local impingement and pain
• XR shows bony spur that arises from surgace of cortex and usually points away from joint (califlower exostosis)

Question 5

Langerhans cell histiocytosis

Answer 5

• Immune dysregulation
• Children age 3-5
• Skull is most common site, also long bone and vertebrae
• May have posterior pit involvement (think DI and growth hormone def)

Question 6

Fibrous cortical defect

Answer 6

• Most common of all focal bone lesions
• Ages 4-8
• Generally asymptomatic and resolve spontaneously
• Occurs near epiphyseal growth plate at sites of tendon or ligament insertion (distal femur or proximal tibia)

Question 7

Unicameral bone cyst

Answer 7

• Later childhood
• Metaphysis of proximal humerus or femur
• Pain or pathological fracture, may also be asymptomatic
• XR shows an expansile lesion with minimal sclerosis

Question 8

Aneurysmal bone cyst

Answer 8

• Adolescent girl
• pain and swelling, typically in long bones but also spine and pelvis
• XR expansile lesion, CT lytic lesion, MRI fluid levels within the cysts

Question 9

Osteosarcoma

Answer 9

• Most common pediatric malignant tumor
• 16 years, male
• Pain followed by development of tender swelling of hard consistency +/- pathological fractures
• Fever, weight loss and fatigue NOT common
• Metaphysis and metadiaphysis of long bones most common
• 20 percent have mets typically to lung or other bones
• Lesion starts in medullary cavity, invades the cortex, elevates the periosteum, creates a triangle of immature bone, then into surrounding tissue forming a soft tissue mass

Question 10

Ewing’s Sarcoma

Answer 10

• Second most common primary bone tumor
• Second decade though may be very young
• Limbs or axial skeleton
• Intermittent pain and swelling usually a long time until diagnosis
• Pathological fractures
• Systemic features may include fever and weight loss
• XR shows destruction lesion which may have classic “onion skin” appearance due to areas of tumor lysis with periosteal reaction or may have spiculated pattern of new bone formation

Question 11

Neuroblastoma

Answer 11

• Most common extracranial solid tumor
• Arises from tissues of Sympathetic nervous system
• Metastatic at presentation in 2/3 marrow to bone
• Weight loss, pallor. limb and abdominal pain, refuse to ambulate, proptosis, raccoon eyes
• Urine with elevated adrenergic metabolics
• Elevated ferritin

Question 12

Wilm’s tumor

Answer 12

• Most common pediatric renal malignancy
• Abdominal mass or swelling, abd pain, hematuria, fever, HTN
• Lung is most common met but can also go to liver, bone, or brain

Question 13

Pigmented villonodular synovitis

Answer 13

• Locally aggressive synovial proliferative disorder affecting joints, tendon sheaths and bursae
• Painful effusion of the knee
• Joint aspirate suggests hemarthrosis and poor response to steroids
• Histo shows thickened reddish brown synovium due to hemosiderin deposition, with numerous villous projections
• MRI may show blooming phenomenon ( evidence of hemosiderin)

Question 14

Synovial chrondromatosis

Answer 14

• Rare in children
• Monoarticular, usually knee
• Synovial hyperplasia and small round cartilaginous nodules which ossify over time
• Non specific symptoms with pain, effusion and locking

Question 15

Synovial hemangiomas

Answer 15

• Usually affect the knee
• Pain, swelling and decreased ROM
• Reduction in adjacent thigh muscle girth, recurrent hemarthrosis
• May be associated with cutaneous lesions as part of Klippel Trenaunay Weber

Question 16

Synovial Sarcoma

Answer 16

• Not intra-articular or from synovium
• Slowly growing painless mass, usually in lower limb, in periarticular proximity to tendon sheath and bursae
• Spreads to lymph nodes and lungs

Question 17

Juvenile fibromatosis

Answer 17

• Group of disorders
• Can be superficial or deep
• Firm, slow growing and painless swelling attached to underlying soft tissue or bone
• Associated with Gardner and FAP

Question 18

Rhabdomyosarcoma

Answer 18

• Most common soft tissue sarcoma
• Can arise in striated or smooth muscle at any site
• Most common head and neck, GU tract
• Painless mass
• Regional LN involvement

Question 19

Chondrosarcoma

Answer 19

• Rare in children but occurs due to malignant transformation of benign osteochondroma
• Insidious pain, soft tissue mass, fracture

Question 20

Fibrosarcoma

Answer 20

• Two forms: infantile and adolescent
• Infantile has rapidly growing mass in distal extremity, vascular and can be mistake for a hemangioma
• Adolescent form is mass in deep soft tissue, most common males

Question 21

Location of pain in leukemia

Answer 21

metaphyseal but joint swelling can occur