Malignancy

Question 1

How does the region of bone involvement help differentiate osteosarcoma and Ewing’s sarcoma?

Answer 1

Diaphysis: Ewing

Metaphysis: osteosarcoma

Question 2

What are two causes of midline neck lumps in children?

Answer 2

1. Thyroglossal cyst
2. Dermoid cyst

Question 3

What are four causes of lateral neck lumps in children?

Answer 3

1. Lymph nodes (lymphadenitis, malignancies)
2. Brachial cysts/sinuses
3. Cystic hygroma
4. Sternomastoid tumour

Question 4

What laboratory findings are found in osteosarcoma?

Answer 4

Elevated ALP and LDH

Question 5

How are osteosarcomas treated?

Answer 5

Surgical resection

Chemotherapy

Usually resistant to radiotherapy

Question 6

Which gene is affected in hereditary retinoblastoma?

Answer 6

Retinoblastoma tumour suppressor gene

Question 7

Which other cancers is hereditary retinoblastoma associated with?

Answer 7

Osteosarcoma

Pinealoma (pineal gland)

Question 8

What is the most common primary benign bone tumour?

Answer 8

Osteochrondroma (exostosis)

Question 9

What is the most common site for a neuroblastoma?

Answer 9

Adrenal gland

Mass may cross the midline, unlike Wilm’s tumour

Question 10

From what type of cell are neuroblastomas derived?

Answer 10

Neural crest cells

Question 11

How are retinoblastomas inherited?

Answer 11

Autosomal dominant

• 10% are inherited*
• More likely to be bilateral*