Abdo Mass: Hernia & Neuroblastoma Flashcards
What is the most common malignancy in infants (<1 y/o)?
Neuroblastoma
What is a neuroblastoma?
It is a catecholamine secreting cancer.
It develops from early nerve cells (neuroblasts), most commonly in the adrenal glands.
What does a neuroblastoma secrete?
Catecholamines
What is a neuroblastoma specifically comprised of?
Neural crest cells
What age is a neuroblastoma typically seen in?
<5 y/o
Where does a neuroblastoa typically start?
In the abdomen
Metastasis of a neuroblastoma?
Has a 50% risk of metastasising to bones, liver and skin, through haematological and lymphatic spread.
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) Hirschsprung’s disease
3) Congenital central hypoventilation syndrome
4) Neurofibromatosis type 1
What is a neuroblastoma derived from?
The ventrolateral neural crest cells in the neuroectoderm, which migrate from the neural tube during early embryogenesis.
Where do neuroblastomas arise? (3 locations)
1) Adrenal medulla (30%)
2) Abdominal paraspinal ganglia (60%)
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 the 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 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
What is referral time for suspected neuroblastoma?
Appointment within 48 hours
Investigations in a neuroblastoma?
1) Urine catecholamines
2) Bloods:
- FBC
- U&Es
- LFTs
- Serum catecholamines (elevated)
- LDH (may be elevated)
3) Imaging:
- abdo USS
4) Others:
- MIBG scan
- Bone scan
- Biopsy to determine type of tumour.
What is a sensitive and specific marker for neuroblastoma?
Urine 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?
The breakdown products of noradrenaline and adrenaline.
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
What may U&Es show in a neuroblastoma?
Tumour lysis syndrome (should be treated prior to chemotherapy)
1st line imaging in a neuroblastoma?
Abdo USS
What is the most common differential for a neuroblastoma?
Wilm’s tumour
Both present with an unexplained abdominal mass
What is Wilm’s tumour often accompanied by?
1) Haematuria
2) The presence of congenital overgrowth syndrome (e.g., Beckwith-Wiedemann syndrome, Perlman syndrome, Sotos syndrome).
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 are the 4 staging groups for a neuroblastoma?
L1: localised tumour not involving vital structures, as defined by the list of IDRFs (below), and confined to one body compartment
L2: local-regional tumour with presence of one or more IDRFs
M: distant metastatic disease (except stage MS tumour)
MS: metastatic disease in children younger than 18 months, with metastases confined to the skin, liver, and/or bone marrow.
What is required to diagnose a neuroblastoma?
Biopsy
How does age affect outcome in neuroblastoma?
the younger the patient, the better the survival rate
1st line treatment for ‘low risk’ neuroblastoma?
Surgery is the first line treatment for patients who can safely have more than 50% of the tumour removed.
This may be followed by chemotherapy.
1st line management for ‘intermediate risk’ neuroblastoma?
chemotherapy
surgery is also recommended
1st line management for ‘high risk’ neuroblastoma?
1) Started on induction chemotherapy.
2) High dose chemotherapy
3) Followed by autologous bone marrow transplant
What 4 chemotherapy agents are involved in the management of neuroblastoma?
1) carboplatin
2) etoposide
3) cyclophosphamide
4) doxorubicin
What is used for maintenance therapy of neuroblastoma?
Isotretinoin –> promotes differentiation of neuroblastoma cells into normal cells.
What are the 3 key complications of a hernia?
1) Incarceration
2) Obstruction
3) Strangulation
What is incarceration of a hernia?
When the hernia cannot be reduced back into the proper porition (it is irreducible).
The bowel is trapped in the herniated position.
Incarceration can lead to obstruction and strangulation of the hernia.
What is a hernia?
Hernias occur when there is a weak point in a cavity wall, usually affecting the muscle or fascia. This weakness allows a body organ (e.g., bowel) that would normally be contained within that cavity to pass through the cavity wall.
What is obstruction in a hernia?
Obstruction is where a hernia causes a blockage in the passage of faeces through the bowel.
Presents with vomiting, generalised abdominal pain and absolute constipation (not passing faeces or flatus).
What is strangulation of a hernia?
Where a hernia is non-reducible (it is trapped with the bowel protruding) and the base of the hernia becomes so tight that it cuts off the blood supply, causing ischaemia.
What is a Richter’s hernia?
A very specific situation that can occur in any abdominal 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.
Management of strangulated Richter’s hernias?
Should be operated on immediately
What is Maydl’s hernia?
A specific situation where 2 different loops of bowel are contained within the hernia.