Abdo Mass: Hernia & Neuroblastoma Flashcards
(119 cards)
1
Q
What is the most common malignancy in infants (<1 y/o)?
A
Neuroblastoma
2
Q
What is a neuroblastoma?
A
It is a catecholamine secreting cancer.
It develops from early nerve cells (neuroblasts), most commonly in the adrenal glands.
3
Q
What does a neuroblastoma secrete?
A
Catecholamines
4
Q
What is a neuroblastoma specifically comprised of?
A
Neural crest cells
5
Q
What age is a neuroblastoma typically seen in?
A
<5 y/o
6
Q
Where does a neuroblastoa typically start?
A
In the abdomen
7
Q
Metastasis of a neuroblastoma?
A
Has a 50% risk of metastasising to bones, liver and skin, through haematological and lymphatic spread.
8
Q
What are 4 medical conditions that are related to aberrant neural crest development (and therefore increase the risk of developing neuroblastoma)?
A
1) Turner’s syndrome
2) Hirschsprung’s disease
3) Congenital central hypoventilation syndrome
4) Neurofibromatosis type 1
9
Q
What is a neuroblastoma derived from?
A
The ventrolateral neural crest cells in the neuroectoderm, which migrate from the neural tube during early embryogenesis.
10
Q
Where do neuroblastomas arise? (3 locations)
A
1) Adrenal medulla (30%)
2) Abdominal paraspinal ganglia (60%)
3) Remainder from the sympathetic ganglia in the chest, head/neck and pelvis
11
Q
What do neural crest cells go on to form?
A
Sympathetic chain and the adrenal glands in the lumbar area.
12
Q
What 2 oncogenes can be implicated in neuroblastoma?
A
1) MYCN oncogene
2) ALK oncogene
13
Q
What is the most common presenting symptom of a neuroblastoma?
A
Lump or swelling in abdomen
14
Q
Clinical features of a neuroblastoma?
A
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
15
Q
What % of children with a neuroblastoma will have a metastasis?
A
70%
16
Q
What are some symptoms of metastasis of a neuroblastoma?
A
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
17
Q
Referral criteria for a neuroblastoma?
A
Very urgent referral (<48 hours) children with a palpable abdominal mass or unexplained enlarged abdominal organ.
18
Q
What is the most common site of metastasis of a neuroblastoma?
A
Bone
19
Q
What is referral time for suspected neuroblastoma?
A
Appointment within 48 hours
20
Q
Investigations in a neuroblastoma?
A
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.
21
Q
What is a sensitive and specific marker for neuroblastoma?
A
Urine catecholamines
22
Q
What do urinary catecholamines typically show in a neuroblastoma?
A
High levels of the tumour markers vanillylmandelic acid (VMA) and homovanillic acid (HVA)
23
Q
What are VMA and HVA?
A
The breakdown products of noradrenaline and adrenaline.
24
Q
What may a FBC show in a neuroblastoma?
A
Pancytopenia –> suggests metastasis
25
If FBC shows pancytopenia in a neuroblastoma, what do patients need prior to biopsy?
Blood or platelet transfusion
26
What may U&Es show in a neuroblastoma?
Tumour lysis syndrome (should be treated prior to chemotherapy)
27
1st line imaging in a neuroblastoma?
Abdo USS
28
What is the most common differential for a neuroblastoma?
Wilm's tumour
Both present with an unexplained abdominal mass
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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).
30
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)
31
What is the staging system for a neuroblastoma based on?
image-defined risk factors (IDRFs)
32
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.
33
What is required to diagnose a neuroblastoma?
Biopsy
34
How does age affect outcome in neuroblastoma?
the younger the patient, the better the survival rate
35
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.
36
1st line management for 'intermediate risk' neuroblastoma?
chemotherapy
surgery is also recommended
37
1st line management for 'high risk' neuroblastoma?
1) Started on induction chemotherapy.
2) High dose chemotherapy
3) Followed by autologous bone marrow transplant
38
What 4 chemotherapy agents are involved in the management of neuroblastoma?
1) carboplatin
2) etoposide
3) cyclophosphamide
4) doxorubicin
39
What is used for maintenance therapy of neuroblastoma?
Isotretinoin --> promotes differentiation of neuroblastoma cells into normal cells.
40
What are the 3 key complications of a hernia?
1) Incarceration
2) Obstruction
3) Strangulation
41
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.
42
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.
43
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).
44
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.
45
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.
46
Management of strangulated Richter’s hernias?
Should be operated on immediately
47
What is Maydl’s hernia?
A specific situation where 2 different loops of bowel are contained within the hernia.
48
What is an inguinal hernia?
A protrusion of all or part of a viscus through the wall of the abdominal or pelvic cavity in which is normally contained, causing a visible or easily palpable bulge.
49
Risk factors for inguinal hernias?
1) Male sex (95%)
2) Older patients (>75)
3) Collagen defect e.g. Marfan's, Ehlers-Danlos
4) Previous RLQ incisions e.g. appendectomy
5) Premature babies
50
How do inguinal hernias present?
Soft lump in the inguinal region
51
What are the 2 types of inguinal hernias
1) direct
2) indirect
52
What are the 2 types of groin hernias?
Inguinal & femoral
53
What is the inguinal ligament?
This ligament runs between the ASIS and the pubic tubercle.
Just above this ligament runs a structure known as the inguinal canal.
54
What is the function of the inguinal canal?
To provide a passageway between the peritoneal cavity and the external genitalia.
55
What does the inguinal canal transmit in men only?
The spermatic cord to the testis
56
What does the inguinal canal contain in women only?
The round ligament
57
What does the inguinal canal contain in both men and women?
The ilioinguinal nerve and the genital branch of the genitofemoral nerve.
58
Entry & exit point of the inguinal canal?
Entry - deep inguinal ring
Exit - superficial inguinal ring
59
Location of the deep inguinal ring?
Just above the midpoint of the inguinal ligament
60
Location of the superficial inguinal ring?
Just above and lateral to the pubic tubercle
61
What is a DIRECT inguinal hernia caused by?
Weakness in the POSTERIOR wall of the inguinal canal, in an area known as Hesselbach’s triangle.
Abdominal contents (usually just fatty tissue, sometimes bowel) are forced “directly” through this defect into the inguinal canal.
62
Where does a DIRECT hernia enter & exit the inguinal canal?
Enters medial to the deep ring
Exists via the superficial ring
63
What happens in an INDIRECT inguinal hernia?
The abdo contents enter the DEEP ring, pass along the length of the inguinal canal and exit via the superficial ring.
64
Entry of direct vs indirect inguinal hernia into the inguinal canal?
Direct: enters via weakness in posterior wall of canal
Indirect: enters via deep inguinal ring
65
Both types of inguinal hernia exit via the superficial ring and can sometimes enter the scrotum.
What is this known as?
Inguinoscrotal hernia
66
Is it more common for a direct or indirect inguinal hernia to enter the scrotum?
Indirect (as the path through both anatomical inguinal rings offers less resistance).
67
What does the round ligament connect to in females?
Attaches to the uterus, passes through the inguinal canal and then attaches to the labia majora.
68
What exam finding can help you differentiate between indirect and direct inguinal hernias?
Place your finger over the deep inguinal ring (just above the mid-point of the inguinal ligament).
You will be able to control an indirect inguinal hernia which has been reduced.
If when you press the deep ring, the hernia still protrudes, then the hernia is emerging via a defect in the posterior wall medial to this point and is, therefore, a direct hernia.
69
What structure allows the testes to descend from the abdo cavity, through the inguinal canal and into the scrotum in development?
The processus vaginalis
70
What is the processus vaginalis?
A pouch of peritoneum that extends from the abdo cavity through the inguinal canal.
71
What happens to the processes vaginalis after the testes descend through the inguinal canal?
Normally, the deep inguinal ring closes and the processus vaginalis is obliterated.
However, in some patients, the inguinal ring remains patent, and the processus vaginalis remains intact.
This leaves a tract or tunnel from the abdominal contents, through the inguinal canal and into the scrotum.
The bowel can herniate along this tract, creating an indirect inguinal hernia.
72
What is the name of the point of abdo wall weakness in a direct inguinal hernia?
Hesselbach’s triangle
73
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
74
How to locate the deep inguinal ring?
Midway between the ASIS and pubic tubercle
75
Exam technique to differntiate between direct and indirect hernia?
1) Locate the deep inguinal ring (midway between the ASIS and pubic tubercle).
2) Manually reduce the patient’s hernia by compressing it towards the deep inguinal ring, starting at the inferior aspect of the hernia.
3) Once the hernia is reduced, apply pressure over the deep inguinal ring and ask the patient to cough.
If a hernia reappears, it is more likely to be a direct inguinal hernia; if it does not, it is more likely to be an indirect inguinal hernia.
76
Many inguinal hernias are otherwise asymptomatic.
How may symptomatic hernias present?
- Groin lump
- Groin pain or discomfort (particularly after coughing, bending over or standing for long periods)
- Pain or altered sensation over scrotum or inner thigh (due to compression of the ilioinguinal nerve)
- Changes in bowel habit or urinary symptoms (depending on the contents of the hernia)
- Incarcerated, obstructed or strangulated (rare)
77
What is the gold standard management for inguinal hernias?
Mesh repair.
This is either via open or laparoscopic surgery:
- unilateral inguinal hernias --> generally repaired with an open approach
- bilateral and recurrent inguinal hernias --> generally repaired laparoscopically
78
What is a femoral hernia?
When a section of the bowel or any other part of the abdominal viscera pass into the femoral canal into the medial upper thigh.
79
How do femoral hernias frequently present?
Bowel obstruction
80
Where is the femoral canal located?
Just medial to the femoral vein
81
What is the function of the femoral canal?
To allow expansion of the femoral vein to increase venous return from the lower limb.
82
What does the femoral canal normally contain?
1) a small amount of fatty tissue
2) a lymph node (the lymph node of Cloquet)
83
Why are femoral hernias at HIGH RISK of strangulation or obstruction?
As the femoral canal is a narrow space bordered medially by the sharp edge of the lacunar ligament.
84
Are femoral hernias more common in men or women?
Women
85
Risk factors for femoral hernia?
- female
- increased age
- low BMI
86
Location of femoral vs inguinal hernia?
Femoral --> located below and lateral to the pubic tubercle.
Inguinal --> situated above and medial to the pubic tubercle.
87
What imaging can be used to confirm the diagnosis of a femoral hernia?
US
88
Management of femoral hernia?
Due to the high risk of complications, femoral hernias should ALWAYS be repaired.
Best method --> laparoscopic mesh repair.
89
What are the clinical features of a strangulated hernia?
- Episodes of pain in a hernia that was previously asymptomatic
- Irreducible hernias
- Pain
- Fever
- Increase in the size of a hernia or erythema of the overlying skin
- Peritonitic features such as guarding and localised tenderness
- Bowel obstruction e.g. distension, nausea, vomiting
- Bowel ischemia e.g. bloody stools
90
What is an incisional hernia?
Occurs at the site of an incision from previous surgery.
Due to weakness where the muscles and tissues were closed after a surgical incision.
91
How are incisional hernias often managed?
They are often left alone if they are large, with a wide neck and low risk of complications, particularly in patients with multiple co-morbidities.
92
What are umbilical hernias?
Umbilical hernias occur around the umbilicus due to a defect in the muscle around the umbilicus.
93
Who are umbilical hernias common in?
Neonates
94
What is an epigastric hernia?
a hernia in the epigastric area (upper abdomen).
95
What is an obturator hernia?
An abnormal protrusion of abdominopelvic contents through the obturator foramen of the bony pelvis into the medial upper thigh.
Very rare (<1% of all hernias).
96
What is the obturator foramen?
An anterior opening formed by the rami of the pubis and ischium on either side of the pelvis.
The largest foramen in the human body.
97
What structures pass through the obturator foramen?
The obturator artery, vein and nerve.
These leave the pelvis, pass through the obturator foramen to enter the medial compartment of the thigh.
98
Who are obturator hernias most common in?
- Women
- Particularly in older age
- Multiparous
- Low BMI
99
How do most obturator hernias present?
As an emergency with an acute abdomen and clinical features of bowel obstruction and/or strangulation.
100
Clinical features of an obturator foramen?
- Acute abdomen symptoms
- Hardly ever a lump (due to deep position)
- Pain and altered sensation along the inner thigh
- Howship-Romberg sign
101
What causes pain and altered sensation along the inner thigh in an obturator hernia?
Due to compression of the obturator nerve by the hernia
102
What is Howship-Romberg sign?
Pain extended from the inner thigh to the knee when the hip is internally rotated, but is relieved by flexing the hip.
103
What is Howship-Romberg sign pathognomonic for?
Obturator hernia
104
What is the gold standard diagnostic test for an undifferentiated acute abdomen?
CT scan of the abdomen and pelvis with portal venous contrast
(should accurately identify an obturator hernia).
105
Management of obturator hernia?
Obturator hernias generally require emergency surgery.
106
What is a true (or direct) umbilical hernia?
A congenital problem which occurs when the umbilical ring fails to close, resulting in herniation of intra-abdominal contents into the middle of the cicatrix.
This is extremely common, especially in children.
107
What are the 2 types of midline hernias?
1) Epigastric hernia
2) Umbilical hernia
108
What is an epigastric hernia?
When abdo organs herniate through the linea alba (between the xyphoid process and umbilicus).
109
What is an umbilical hernia?
Abdo organ protrudes through the umbilicus.
110
Cause of an indirect inguinal hernia?
Processus vaginalis fails to close --> congenital hernia.
Typically seen in infants & children.
111
Describe
Intestines herniate lateral to the inferior epigastric vesels and through the inguinal canal, ending in the scrotum.
112
Cause of a direct inguinal hernia?
Acquired hernia.
Caused by weakening in transversalis fascia.
113
Age of indirect vs direct inguinal hernias?
Indirect --> infants & children
Direct --> middle aged & elderly
114
Where is most common area of weakness in a direct inguinal hernia?
An area in the posterior wall of inguinal canal --> called Hesselbach triangle.
115
Borders of Hesselbach triangle?
Medially --> lateral border of rectus abdominis
Superolaterally --> epigastric vessels
Inferiorly --> inguinal ligament
116
What may precede a direct inguinal hernia?
Result of increased abdo pressure e.g. heavy lifting, coughing.
117
What is an incarcerated hernia?
What does this result in?
When the contents cannot be pushed back.
Results in decreased venous and lymphatic flow --> oedema & swelling of incarcerated tissue.
Can eventually lead to strangulation (i.e. lack of blood flow) --> ischaemia --> tissue necrosis.
118
Role of isotretinoin in maintenance therapy in treatment of neuroblastoma?
Isotretinoin promotes the differentiation of neuroblastoma cells into normal cells.
119
