Bone Tumors in Children

Question 1

Clinical features

Answer 1

Intermittent pain
Antalgic flexion
Palpable local mass

Question 2

Malignant bone tumors diagnosis

Answer 2

Delayed, in most cases

based on the laboratory findings and imaging (X-ray, CT, MRI, scintigraphy, angiography)

Question 3

Diagnosis – laboratory findings

Answer 3

1. The serum alkaline phosphatase – reflects osteogenesis in the neoplastic tumor. The level falls to near normal after ablation and rises with the development of metastases and with recurrence.
2. Creatinkinasis and lactate dehydrogenase are constantly elevated, they normalise only after en block resection

Question 4

Osteosarcoma

Answer 4

• Most frequent malignant bone tumor in children
• Develops in the metaphysis of long bones
• Common sites: distal femur and proximal tibia
• Age 10-20

Question 5

Osteosarcoma – radiographic findings (I)

Answer 5

eccentric metaphyseal radiolucent defect with an irregular, ill-defined contour

Question 6

Osteosarcoma – radiographic findings (II)

Answer 6

destruction of the nearest cortical wall, in the middle of the tumor appear areas of increased radiopacity (new bone formation)

Question 7

Osteosarcoma – radiographic findings (III)

Answer 7

Subperiosteal reaction –
“sunburst” appearance
(is produced by the formation of spicules of new bone laid down perpendicular to the shaft along the vessels passing from the periosteum to the cortex)

Question 8

Osteosarcoma – radiographic findings (IV)

Answer 8

Codman’s triangle – ossified elevated periosteum due to the rapid growing process (advanced stage) – 2 and a half years of tumor progression

Question 9

Ewing sarcoma

Answer 9

The second most common primary malignant bone tumor in children

Location: pelvis, long bones, flat bones

Question 10

Ewing’s sarcoma – radiographic findings (I)

Answer 10

The normal trabecular pattern is lost

The radiographic appearance is characteristic but not pathognomonic

Question 11

Ewing’s sarcoma – radiographic findings (II)

Answer 11

Permeative lesion with mottled rarefaction of the medullary cavity and invasion through the overlying cortex

Question 12

Ewing’s sarcoma – radiographic findings (III)

Answer 12

• Extraperiosteal extension
• Soft tissue mass adjacent to the area of bone destruction
• 18 months of evolution

Question 13

Chondrosarcoma

Answer 13

• Cartilaginouse malign tumor
• Rare in children
• Develops on a pre-existing benign cartilaginous lesion

Question 14

Chondrosarcoma – radiographic findings

Answer 14

Multiple irregular masses with calcification of varying density on a radiolucent area

Question 15

Giant cell tumor

Answer 15

4th grade giant cell tumor of proximal femur, without the growing plate invasion

4th grade giant cell tumor of proximal tibia with growing plate invasion

Question 16

Imaging ‘

Answer 16

1.Technetium scintigraphy shows the tumoral active area

2. Computed tomography shows:
   - Extension of the tumor in the soft tissues, bone metastases of 2mm or more and pulmonary metastasis of 3 mm or larger
   - Useful when planning the osteotomies
3. Magnetic Resonance Imaging
   - Soft tissue extension and the relationship with the neurovascular structures. (important for planning limb-sparing resection)
   - Relationship with the growing plate (important for planning arthroplastic reconstruction)
4. Angiography
   - Shows occult metastasis (in the arterial phase) and establishes the resection area (in the venous phase)

Question 17

Treatment

Answer 17

Multidisciplinary team: oncologist, orthopedic surgeon, pathologist, radiologist and physiokinetotherapist

Treatment phases:
Open biopsy (for the final diagnosis)
Preoperative chemotherapy
Therapeutic reevaluation
Surgical treatment 
Postoperative treatment

Question 18

Open biopsy

Answer 18

Provides specimens for hystological diagnosis, necessary to obtain a final diagnostic

it should contain all layers: skin, subcutaneous tissue, fascia, muscles, periosteum, compact bone and medullary canal content.

Question 19

Preoperative treatment

Answer 19

The preoperative chemotherapy should be followed for at least 4 to 6 months before the surgery

Preoperative treatment aims to:

• Diminish the local edema;
• Shrink the tumor and local extensions;
• Destroy occult metastasis.

Question 20

Therapeutic purpose

Answer 20

• saving the patient’s life
• saving the limb
• maintaining the limb’s function
• preserving the limb’s lenght

                           aim 

• Oncological en block resection
• Osteoplastic or osteoarthroplastic reconstruction

Question 21

Physis conservation

Answer 21

• CT
• MRI
• Bone scintigraphy
• Selective angiogram

Question 22

Physeal invasion tumor

Answer 22

Tumoral endoprosthesis

- without the possibility of lenghtening 100% of our cases