Revision - Neuroblastoma

Question 1

What is the most common malignancy in infants (<1 y/o)?

Answer 1

Neuroblastoma

Question 2

What is a neuroblastoma?

Answer 2

A catecholamine secreting cancer

Question 3

Where does a neuroblastoma develop from?

Answer 3

Develops from early nerve cells (neuroblasts), most commonly in the adrenal glands.

Question 4

What does a neuroblastoma secrete?

Answer 4

Catecholamines

Question 5

What are 4 medical conditions that are related to aberrant neural crest development (and therefore increase the risk of developing neuroblastoma)?

Answer 5

1) Turner’s syndrome
2) NF1
3) Hirschsprung’s disease
4) Congenital central hypoventilation syndrome

Question 6

Most common location for a neuroblastoma to arise from?

Answer 6

Abdominal paraspinal ganglia (60%)

Question 7

Where do neuroblastomas arise? (3 locations)

Answer 7

1) abdominal paraspinal ganglia
2) adrenal medulla
3) remainder from the sympathetic ganglia in the chest, head/neck and pelvis

Question 8

What do neural crest cells go on to form?

Answer 8

Sympathetic chain and adrenal glands in the lumbar area.

Question 9

What 2 oncogenes can be implicated in neuroblastoma?

Answer 9

1) MYCN oncogene

2) ALK oncogene

Question 10

What is the most common presenting symptom of a neuroblastoma?

Answer 10

Lump or swelling in the abdomen

Question 11

Clinical features of a neuroblastoma?

Answer 11

1) Mass effect of primary lesion:
- constipation
- abdo distension

2) Effects of metastases e.g. bone pain

3) Generalised symptoms:
- fatigue
- malaise
- fever
- failure to thrive

Question 12

What % of children with a neuroblastoma will have a metastasis?

Answer 12

70%

Question 13

What are some symptoms of metastasis of a neuroblastoma?

Answer 13

1) Spinal cord: numbness, weakness, loss of movement at the level of the spinal cord

2) Neck: breathlessness, dysphagia, Horner’s syndrome

3) Bone: pain and swelling

4) Bone marrow:
- thrombocytopenia (bleeding and bruising)
- anaemia (fatigue, SOB, pallor)
- leukopenia (increased infections)

5) Skin: small, raised, blue/black discoloured lumps

6) Liver: hepatomegaly and abdominal pain

Question 14

Referral criteria for a neuroblastoma?

Answer 14

Very urgent referral (<48 hours) children with a palpable abdominal mass or unexplained enlarged abdominal organ.

Question 15

What is the most common site of metastasis of a neuroblastoma?

Answer 15

Bone.

Question 16

Key investigation in a neuroblastoma?

Answer 16

Urinary catecholamines

Question 17

What do urinary catecholamines typically show in a neuroblastoma?

Answer 17

High levels of the tumour markers vanillylmandelic acid (VMA) and homovanillic acid (HVA)

Question 18

What are VMA and HVA?

Answer 18

Breakdown products of adrenaline and noradrenaline

Question 19

What may a FBC show in a neuroblastoma?

Answer 19

Pancytopenia –> suggests metastasis

Question 20

If FBC shows pancytopenia in a neuroblastoma, what do patients need prior to biopsy?

Answer 20

Blood or platelet transfusion

Question 21

1st line imaging in a neuroblastoma?

Answer 21

Abdo US

Question 22

What is the most common differential for a neuroblastoma?

Answer 22

Wilm’s tumour (nephroblastoma)

Both present with an unexplained abdominal mass

Question 23

What will a CT or MRI of the abdomen or pelvis show in Wilm’s tumour?

Answer 23

CT or MRI of the abdomen or pelvis shows claw sign (a renal mass with parenchyma stretching around the tumour)

Question 24

What is the staging system for a neuroblastoma based on?

Answer 24

image-defined risk factors (IDRFs)

Question 25

What is required to diagnose a neuroblastoma?

Answer 25

Biopsy

Question 26

What is used for maintenance therapy of neuroblastoma?

Answer 26

Isotretinoin –> promotes differentiation of neuroblastoma cells into normal cells.

Question 27

What is a Richter’s hernia?

Answer 27

This is where only part of the bowel wall and lumen herniate through the defect, with the other side of that section of the bowel remaining within the peritoneal cavity.

Can become strangulated.

Question 28

What is Maydl’s hernia?

Answer 28

A specific situation where 2 different loops of bowel are contained within the hernia.

Question 29

Location of the deep inguinal ring?

Answer 29

Just above the midpoint of the inguinal ligament (this runs from the ASIS to the pubic tubercle)

Question 30

Location of the superficial inguinal ring?

Answer 30

Just above and lateral to the pubic tubercle

Question 31

What is the name of the point of abdo wall weakness in a direct inguinal hernia?

Answer 31

Hesselbach’s triangle

Question 32

Boundaries of Hesselbach’s triangle boundaries (RIP mnemonic)?

Answer 32

R – Rectus abdominis muscle – medial border

I – Inferior epigastric vessels – superior / lateral border

P – Poupart’s ligament (inguinal ligament) – inferior border

Question 33

How to locate the deep inguinal ring?

Answer 33

Midway between the ASIS and pubic tubercle

Question 34

What is the gold standard management for inguinal hernias?

Answer 34

Mesh repair

Question 35

How do femoral hernias frequently present?

Answer 35

Bowel obstruction

Question 36

Where is the femoral canal located?

Answer 36

Just medial to the femoral vein

Question 37

What imaging can be used to confirm the diagnosis of a femoral hernia?

Answer 37

US

Question 38

Management of femoral hernia?

Answer 38

Due to the high risk of complications, femoral hernias should ALWAYS be repaired.

Best method –> laparoscopic mesh repair.

Question 39

What is the gold standard diagnostic test for an undifferentiated acute abdomen?

Answer 39

CT scan of the abdomen and pelvis with portal venous contrast

Question 40

Management of obturator hernia?

Answer 40

Obturator hernias generally require emergency surgery.

Question 41

Cause of an indirect inguinal hernia?

Answer 41

Processus vaginalis fails to close –> congenital hernia.

Question 42

Age of indirect vs direct inguinal hernias?

Answer 42

Indirect –> infants & children

Direct –> middle aged & elderly