deck_Bone tumors

Question 1

What are the origins of Primary Malignant Bone tumours?

Answer 1

• Hematopoietic > 40%* Chondrogenic > 20%* Osteogenic > 20%* Unknown 10%

Question 2

What are the 3 Most Common Malignant tumours ofBone ?

Answer 2

1. Osteosarcoma2. Chondrosarcoma3. Ewing sarcoma

Question 3

What are the risk factors for osteosarcoma ?

Answer 3

• Retinoblastoma* Hx of radiation tx* Hx of high bone turnover (e.g., Paget Disease of Bone)

Question 4

What are the most common locations of osteosarcoma ?

Answer 4

Distal femur and proximal tibia = 60%
Proximal femur =15%
Proximal humerus = 10%
Mandible = 8%

Question 5

What is the epidemiology of osteosarcoma ?

Answer 5

It is more common in boys than girl. It accounts for 50% of bone cancers in those <20 years. It is also the 5th most common cancer between 15-19 year olds.

Question 6

What are the symptoms of osteosarcoma?

Answer 6

Dull aching pain over the involved area, night pain and growing pain with or without B symptoms.

Question 7

What are the signs of Osteosarcoma ?

Answer 7

Patients often have tenderness to palpation on the involved area. Limited AROM of adjacent joints. They may also present with or without swelling, mass, deformity or Spontaneous fracture.

Question 8

What are the imaging studies in osteosarcoma?

Answer 8

• Regional MRI and CT helpful forguiding surgical repair.
• Evaluation for metastatic pulmonarydisease
• Pre-op: All patients get chest CT
  ** Post-op: Repeat chest CT q 3-6 mo x 2 yr.
• Bone scintigraphy: May show distant metastatic lesions or local invasion.

Question 9

What is the significance of biopsy in osteosarcoma?

Answer 9

Percutaneous needle biopsy is sufficient to make the diagnosis and staging.

Question 10

What is the Enneking System for Staging Osteosarcomas?

Answer 10

Stage 1: Low grade no mets, 1A- intra compartmental and 1B extra compartmental. Stage 2: High grade no mets, IIA intra compartmental and IIB extra compartmental. Stage 03: Low or High grade with Mets.

Question 11

What is the Tx of osteosarcoma ?

Answer 11

Methotrexate, Doxorubicin, and Cisplatin for 10 week, Surgery on the 11th week, followed by same chemo protocol for a year.

Question 12

What should be the post surgical follow up in osteosarcoma patients ?

Answer 12

There is 70 to 85% long-term survival rate in osteosarcoma. However relapses are common therefore monitoring as follows is essential:* In the first year blood work and imaging every 3 months.* Same screening continued every 6 months for the next 2 years. * Then yearly. * Chest CT must be done every 6 months for the first 2 years due to the risk of mets into the lungs.

Question 13

What is the prognosis of Osteosarcoma?

Answer 13

• 5-Year survival – 70%* Influenced by metastases at time of diagnosis* Response to neoadjuvant chemo is major prognostic indicator

Question 14

What is the pathophysiology of osteosarcoma?

Answer 14

The pathogenesis of osteosarcoma consist of RB and tp53 mutations triggering uncontrolled proliferation of pleomorphic osteoblasts around the metaphysis of the long bones such as tibia and fibula leading to the symptomatology and radiological sunburst appearance and Codman’s triangle.

Question 15

What is a chondrosarcoma ?

Answer 15

It is a cartilaginous tumor and is the 3rd most common bone malignancy after multiple myeloma and osteosarcoma. 90% are conventional chondrosarcomas followed by dedifferentiated, clear cell, mesenchymal, and juxtacortical subtypes. Secondary chondrosarcoma can arise from enchondroma or osteochondromas.

Question 16

what are the grades of Chondrosarcoma?

Answer 16

Grade I (low grade)* Grade II (intermediate grade)* Grade III (high grade)

Question 17

What is the epidemiology of Chondrosarcoma?

Answer 17

It is equally seen in both genders between the age of 50 and 70.

Question 18

What is the clinical presentation of Chondrosarcoma?

Answer 18

• Deep, dull, achy pain* Chronic (> 1 year)* Pain at night

Question 19

what is the distribution of chondrosarcoma ?

Answer 19

27% on Pelivs, 13% on ribs, 12% on proximal femur, 7% on proximal humerus, 6% on distal femur and 4% on proximal tibia.

Question 20

What is the Tx and prognosis of Chondrosarcoma ?

Answer 20

• Surgical resection* Does not respond well to chemo or radiation* Prognosis* Grade I tumours - 90% survival at 5 years* Grade II tumours - 81% survival at 5 years* Grade III tumours - 29% survival at 5 years

Question 21

What is the epidemiology and pathophysiology of Ewing’s sarcoma ?

Answer 21

It is seen in patients between the age of 5-30. The oncogenesis is mediated by the fusion gene formed from t11,22 translocation.

Question 22

What is the presentation of Ewing sarcoma ?

Answer 22

Bone pain and B symptoms with tender palpable mass on examination.

Question 23

What are the imaging findings in Ewing’s sarcoma ?

Answer 23

Sun burst sign, Onion skin sign and moth eaten pattern.

Question 24

What is the diagnostic work-up in Ewing’s sarcoma ?

Answer 24

Blood works will show elevated WBC, ESR and LDH.Biopsy for histopathological confirmation and MRI for staging.

Question 25

What is the Tx of Ewing’s sarcoma ?

Answer 25

The Tx is surgery, radiation and chemo. The 5 year survival in local disease is 70% and metastatic disease is 30%.

Question 26

What is the pathogenesis and clinical Hx of ganglion cyst?

Answer 26

It is caused by the destruction of mucoid connective tissue. Patient’s will typically complaint of joint instability, weakness and limited ROM.

Question 27

What are the physical examination findings in Ganglion cysts?

Answer 27

• Normal overlying skin* Compressible, movable mass* Transilluminates* May be adherent to bone, joint, or tendon

Question 28

What is the Tx of Ganglion cyst?

Answer 28

It often doesn’t require any Tx. If needs to be treated :* Noninvasive* Compression* Aspiration* Surgical* Open excision* Requires post-op immobilization x7 days* Recurrence* Ranges from 4% to 40%

Question 29

What is the genetic mutation in Ewing sarcoma?

Answer 29

EWSR1- FLI1 fusion gene.

Question 30

What is the histopathological appearance of Ewing sarcoma?

Answer 30

Small round blue cells