Module 6: Bone: Osteoclastoma and Ewing's Sarcoma

Question 1

The next tumor is a benign tumor called Osteoclastoma (giant cell tumor), what is the etiology?

Answer 1

Affects 20-40 yr olds

• -can be due to Paget’s disease
• -origin is mesenchyme (Stromal cell of bone)

Question 2

What is the pathogenesis for Osteoclastoma (Giant cell tumor)?

Answer 2

Arises from the epiphysis location of distal femur and proximal tibia (like the chondroblastoma)
–benign tumor of mesenchyme with locally invasive malignant properties

Question 3

What is the presentation for a patient with osteoclastoma?

Answer 3

20-40 yr old person with arthritis like symptoms

–commonly affects the knee

Question 4

What is seen on biopsy for a patient with osteoclastoma?

Answer 4

Multinucleated osteoclast-like giant cells (Reactive) and neoplastic mononuclear stromal cells
(reacting macrophages coming together - giant cells)
–Neoplastic cells are mono-nucleated cells between giant cells from stroma - considered benign

Question 5

What is seen on gross and xray in a patient with osteoclastoma?

Answer 5

Gross: hemorrhagic and cystic and necrosis

X-ray: Soap bubble appearence bc its very cystic and radiolucent

Question 6

What are complications of Osteoclastoma?

Answer 6

Even though its benign it has malignant properties: can invade and mets through blood and lungs

• -can locally invade (locally aggressive) and recurs after removal
• -can be associated with Paget’s disease of bone (most common tumor is osteosarcoma but can also get osteoclastoma)

Question 7

The last bone tumor to touch on is Ewing’s Sarcoma. What is the etiology?

Answer 7

t (11:22) – more common – and t (21:22) in diaphysis of children (less than 20 years old and in boys)
Part of PNET: primitive neuroectodermal tumor (also medulloblastoma in PEDS)

Question 8

What bones are affected in Ewing’s Sarcoma?

Answer 8

Arises from diaphysis

• -affects long bones (Femur, tibia, humerus, ulna and radius)
• -femur most common site

Question 9

What is seen on histology in patients with Ewing’s sarcoma?

Answer 9

Sheets of small round blue cells with small amount of clear cytoplasm
–sometimes seen is pseudorossetes (seen in neuroblastoma)

Question 10

What is seen on biopsy in patients with Ewing’s Sarcoma?

Answer 10

Onion skin appearance (invasion of periosteum)

Question 11

What is the prognosis for patients with Ewings sarcoma?

Answer 11

Dismal (improves with chemo)

–spreads through medullary cavity to cortex then periosteum then to blood and lungs