Revision - Neuroblastoma Flashcards
What is the most common malignancy in infants (<1 y/o)?
Neuroblastoma
What is a neuroblastoma?
A catecholamine secreting cancer
Where does a neuroblastoma develop from?
Develops from early nerve cells (neuroblasts), most commonly in the adrenal glands.
What does a neuroblastoma secrete?
Catecholamines
What are 4 medical conditions that are related to aberrant neural crest development (and therefore increase the risk of developing neuroblastoma)?
1) Turner’s syndrome
2) NF1
3) Hirschsprung’s disease
4) Congenital central hypoventilation syndrome
Most common location for a neuroblastoma to arise from?
Abdominal paraspinal ganglia (60%)
Where do neuroblastomas arise? (3 locations)
1) abdominal paraspinal ganglia
2) adrenal medulla
3) remainder from the sympathetic ganglia in the chest, head/neck and pelvis
What do neural crest cells go on to form?
Sympathetic chain and adrenal glands in the lumbar area.
What 2 oncogenes can be implicated in neuroblastoma?
1) MYCN oncogene
2) ALK oncogene
What is the most common presenting symptom of a neuroblastoma?
Lump or swelling in the abdomen
Clinical features of a neuroblastoma?
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
What % of children with a neuroblastoma will have a metastasis?
70%
What are some symptoms of metastasis of a neuroblastoma?
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
Referral criteria for a neuroblastoma?
Very urgent referral (<48 hours) children with a palpable abdominal mass or unexplained enlarged abdominal organ.
What is the most common site of metastasis of a neuroblastoma?
Bone.
Key investigation in a neuroblastoma?
Urinary catecholamines
What do urinary catecholamines typically show in a neuroblastoma?
High levels of the tumour markers vanillylmandelic acid (VMA) and homovanillic acid (HVA)
What are VMA and HVA?
Breakdown products of adrenaline and noradrenaline
What may a FBC show in a neuroblastoma?
Pancytopenia –> suggests metastasis
If FBC shows pancytopenia in a neuroblastoma, what do patients need prior to biopsy?
Blood or platelet transfusion
1st line imaging in a neuroblastoma?
Abdo US
What is the most common differential for a neuroblastoma?
Wilm’s tumour (nephroblastoma)
Both present with an unexplained abdominal mass
What will a CT or MRI of the abdomen or pelvis show in Wilm’s tumour?
CT or MRI of the abdomen or pelvis shows claw sign (a renal mass with parenchyma stretching around the tumour)
What is the staging system for a neuroblastoma based on?
image-defined risk factors (IDRFs)
What is required to diagnose a neuroblastoma?
Biopsy
What is used for maintenance therapy of neuroblastoma?
Isotretinoin –> promotes differentiation of neuroblastoma cells into normal cells.
What is a Richter’s hernia?
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.
What is Maydl’s hernia?
A specific situation where 2 different loops of bowel are contained within the hernia.
Location of the deep inguinal ring?
Just above the midpoint of the inguinal ligament (this runs from the ASIS to the pubic tubercle)
Location of the superficial inguinal ring?
Just above and lateral to the pubic tubercle
What is the name of the point of abdo wall weakness in a direct inguinal hernia?
Hesselbach’s triangle
Boundaries of Hesselbach’s triangle boundaries (RIP mnemonic)?
R – Rectus abdominis muscle – medial border
I – Inferior epigastric vessels – superior / lateral border
P – Poupart’s ligament (inguinal ligament) – inferior border
How to locate the deep inguinal ring?
Midway between the ASIS and pubic tubercle
What is the gold standard management for inguinal hernias?
Mesh repair
How do femoral hernias frequently present?
Bowel obstruction
Where is the femoral canal located?
Just medial to the femoral vein
What imaging can be used to confirm the diagnosis of a femoral hernia?
US
Management of femoral hernia?
Due to the high risk of complications, femoral hernias should ALWAYS be repaired.
Best method –> laparoscopic mesh repair.
What is the gold standard diagnostic test for an undifferentiated acute abdomen?
CT scan of the abdomen and pelvis with portal venous contrast
Management of obturator hernia?
Obturator hernias generally require emergency surgery.
Cause of an indirect inguinal hernia?
Processus vaginalis fails to close –> congenital hernia.
Age of indirect vs direct inguinal hernias?
Indirect –> infants & children
Direct –> middle aged & elderly
