Clinically oriented approach to a child with abdominal mass. Discussion about Neuroblastoma Discussion about Wilms tumor Discussion about Hepatic tumors Case discussions

1. APPROACH TO A CHILD
WITH AN ABDOMINAL MASS
AND TUMOURS
By
Jwan Ali Ahmed AlSofi

2. Contents:-
• Clinically oriented approach to a child with abdominal mass.
• Discussion about Neuroblastoma
• Discussion about Wilms tumor
• Discussion about Hepatic tumors
• Case discussion

3. The following points need to be considered
when assessing a child with an abdominal mass:
1. Age of the patient and the most likely pathological process
arising in that organ at that age
2. Length of history and type of symptoms, which may also
implicate a particular pathological process (e.g. tenderness of the
mass suggests infection or bleeding)
3. Site of the mass and its precise characteristics, which will
suggest the probable organ of origin

4. Paediatric malignancies

5. Normal and abnormal abdominal masses:-
• The most common abdominal masses in infancy and childhood are non-pathological.
They are usually accounted for by
1. Liver, which normally extends below the right costal margin until 3–4 years of age;
2. Faeces in the colon;
3. Full bladder.
• Three common pathological conditions often present with an abdominal mass in
childhood:
1. Wilms tumour (nephroblastoma),
2. Abdominal neuroblastoma
3. Hydronephrosis.

7. Pathological conditions have certain
features in common:-
1. They are most common in infants and toddlers between 1
and 3 years of age.
2. The mass is typically large when first detected as the
normally protuberant infantile abdomen may conceal
masses of smaller sizes.
3. The mass itself is usually the presenting feature, while
general or local symptoms are typically minimal or
absent.
Neuroblastoma is an exception to the this point: a significant
number of children with neuroblastoma present systemically unwell,
including failure to thrive.

8. DDX of a mass according to its site:-
•A mass situated in the midline in the upper abdomen:-
1. Is most likely a primary abdominal neuroblastoma,
particularly if the child is less than 4 years of age.
2. Massive hepatic metastases (e.g. from a primary neuroblastoma)
3. Primary hepatoblastoma.
•Masses arising in the loin can be palpated extending below
the rib margin towards the iliac fossa and are most likely due
to
1. Hydronephrosis
2. Wilms tumour.

9. 9

10. Stepwise Evaluation of an Abdominal Mass
Clinical History
•Age and gender
•General symptoms
•Pain
•Gastrointestinal symptoms
•Urogenital symptoms
•Pulmonary symptoms
•Family history
•Sexual history
•Weight loss
•Travel
Physical Examination
•General condition
•Lymph nodes
•Associated physical findings
•Cachexia
Abdominal Palpation
•Quadrant of the abdomen
•Organ most likely to be affected
•Characteristics (soft or hard,
mobile or nonmobile, crosses
midline, moves with respiration,
tender)

12. Investigations
• Blood tests:-
- CBC,
- electrolyte analysis
- tumour markers.
• Plain abdominal x-ray
▫ May show calcification within the mass, which is more common in neuroblastoma than Wilms tumour,
and does not occur in hydronephrosis, unless there is a renal stone.
• Abdominal ultrasonography.
▫ Determine whether a mass is cystic or solid
▫ Documents the size, position and extent of a solid tumour and may demonstrate blood vessel involvement
(e.g. extension of a Wilms tumour into the inferior vena cava).
▫ Lymph node involvement and metastases may be demonstrated
• (MRI) and angiography to determine vascular supply have select roles.
• Abdominal (CT) for oncological purposes.
• Nuclear scan:-
- To quantify relative function of each kidney in cases of renal mass/ hydronephrosis
- Reveal the obstruction of the renal tract (MAG3 renogram to investigate hydronephrosis)

15. •Neuroblastoma
▫ Is the most common extra-cranial solid tumour of childhood.
▫ The most common malignancy in infancy.
•The median age at diagnosis is 17 months.
•It is an embryonal tumour that arises from fetal neural crest cells –
neural crest cells form the adrenal medulla and the sympathetic nervous system
•It may occur at any site in the sympathetic nervous system.
•The most common primary sites are
▫ the adrenal gland,
▫ Elsewhere in the abdomen,
▫ the sympathetic chain or the sympathetic plexus in the mediastinum or pelvis.
•Neuroblastoma has wide variety of possible presentations because of :-
1. The numerous sites of primary tumour
2. propensity to early metastasis.

16. Tumour behaviour:-
•Metastases are present in 70% of patients at diagnosis and may
be in the
- bone marrow – Bone and bone marrow are the most frequent sites of metastasis
- cortex of long bones
- lymph nodes – regional or distant,
- skull, eyes,
- Liver
- skin.
•In view of the invasiveness and malignant potential of neuroblastoma
it is a paradox that, in a minority of cases, the tumour regresses
completely with a spontaneous cure.
This unusual tumour behaviour is restricted to children with clinical stage
MS (previously called stage 4S), which is defined as:-
1. Younger than 18 months
2. Presents with metastases strictly confined to the skin, liver and/or bone
marrow.

17. Presentations:-
• Systemic complaints such as fever, weight loss, ill-appearing and pain – more with metastases.
• The most common presentation is abdominal pain or mass.
▫ The mass is often palpated in the abdomen or flank and is hard and nontender.
• Palpable skull nodule due to skull metastases
• Proptosis and periorbital ecchymoses due to ocular metastases
• Horner syndrome due to involvement of the stellate ganglion (sympathetic chain)
• Paraplegia of rapid onset due to intraspinal extension of a paravertebral primary
• Rubbery lymph nodes in the neck or axilla due to lymph node metastases
• Long bone pain and tenderness due to bony metastases
• Bone marrow involvement manifesting as any or all of pain, limping, paralysis or weakness and
failure to thrive with or without anaemia
• Blueberry muffin spots on the skin of infants due to skin metastases
• Diarrhoea caused by tumour metabolites, for example, (VIP)
• Paraneoplastic syndromes:-
▫ secretory diarrhea,
▫ profuse sweating
▫ Opsomyoclonus

18. • Blueberry muffin spots:-
▫ Is the description given to the skin
metastases of Neuroblastoma
▫ Are pathognomonic for clinical stage
MS
Racoon eyes in
neuroblastoma
with CT scan
showing the
tumor

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22. Diagnostic criteria:-
The diagnosis of neuroblastoma requires one or both of the following
criteria:
1. Unequivocal pathologic diagnosis from tumour tissue or raised serum
catecholamines (i.e. dopamine, adrenaline, noradrenaline) or raised urinary
catecholamine metabolites (VMA, HVA)
2. Unequivocal pathologic evidence for bone marrow involvement (evident in
65–75% cases at presentation) together with either raised serum
catecholamines or raised urinary catecholamine metabolites

23. Investigations:-
CBC – anemia, thrombocytopenia, or neutropenia, because of bone marrow
involvement.
Plain radiographs – Calcification within abdominal neuroblastoma tumors
Urinary catecholamines (vanillylmandelic acid; homovanillic acid)
Biopsy. While the diagnosis of neuroblastoma may be made without tumour
biopsy, tissue biopsy for tumour histology and biological features is essential for
risk stratification.
Abdominal CT to look for image-defined risk factors as a part of clinical staging.
Metaiodobenzylguanidine (MIBG) nuclear scan / Bone scan. Identifies
both primary and metastatic lesions.
CT chest, abdomen, and pelvis. Inspect for metastases.
Bilateral bone marrow aspiration and biopsies

24. Staging of Neuroblastoma:-

25. DIFFERENTIAL DIAGNOSIS:-
1. The abdominal presentation of neuroblastoma must be differentiated from Wilms
tumor, which also presents as an abdominal or flank mass.
2. Periorbital ecchymoses from orbital metastases can be mistaken for child abuse.
3. Because children with bone marrow involvement may have anemia, thrombocytopenia,
or neutropenia, leukemia is often considered in the differential.
25

26. Treatment:-
1. Observation only: this is limited to a select group of patients, typically in the under
18-month age group with stage MS disease.
2. Operative excision alone: also limited to a select group of patients.
3. Operative excision with neo-adjuvant and adjuvant chemotherapy: this is
the most common treatment pathway and may be complemented by autologous stem
cell transplant.
4. Radiotherapy: usually reserved for high-risk disease in addition to operative
excision and chemotherapy.
5. Biological and immunological therapies are an increasingly important
component of the treatment regimen in neuroblastoma – usually limited to high- risk
patients and patients with recurrent disease.

27. Prognosis
• The prognosis is highly dependent upon the stage of disease at presentation.
• High-risk disease is currently associated with a 5-year survival rate of 50%.
• Compared with toddlers and older children, infants with neuroblastoma are generally
well, have less aggressive disease, and an excellent prognosis.

29. • Wilms tumour, or nephroblastoma of the kidney, is the most common renal
malignancy in childhood.
• It arises from primitive embryonic metanephric blastemal – the
precursor of a normal kidney.
• The classical location for Wilms tumor is the kidney.
• Rare extrarenal sites:- retroperitoneum, sacrococcygeal region, testis, uterus,
inguinal canal and mediastinum.
• Produces the classic histologic pattern “triphasic”, composed of
- Epithelial structures resembling tubules,
- Blastemal elements of small blue cells,
- Stromal- mesenchymal tissues, including striated muscle fibres ments.
• Wilms tumour is typically sporadic in origin.
• However, it may be associated with a number of syndromes.
• Bilateral disease
▫ is present in 6% of affected children.
▫ More commonly associated with hereditary forms of the disease
▫ Considered stage V.

32. Certain syndromes are at increased risk of
developing Wilms Tumor including:-
1. Beckwith-Wiedemann
2. WAGR (Wilms tumor, aniridia, genitourinary anomalies, and
retardation; mutation involving 11p13 region)
32

33. 33

34. Clinical features:-
• Classic history – abdominal mass found during dressing or bathing
 A smooth loin mass that seldom crosses the midline, but extends down into the iliac fossa and up
under the costal margin.
 A right- sided Wilms tumour may extend behind the liver, which, if pushed down, may present as
hepatomegaly.
 On the left side, a Wilms tumour may be mistaken for an enlarged spleen.
• Children with Wilms tumours are typically well at presentation (80% of cases),
unlike those patients with neuroblastoma.
• Haematuria, often following minor trauma, is the presentation in some children, but
does not indicate a poorer prognosis.
• Elevated blood pressure, may be due to unusual metabolites from the tumour
tissue or compression of the renal vessels
• Pulmonary involvement is the most common metastatic site

36. Investigation:-
• CBC, urinalysis, liver and renal function studies
• Ultrasonography provides detailed information of the site, size and extent of the tumour.
• Doppler ultrasonography also identifies renal vein and inferior vena cava involvement.
Evaluation of the inferior vena cava is crucial because the tumor may extend from the kidney into
the vena cava.
• The liver is examined for the presence of metastases.
• CXR excludes the presence of pulmonary metastases.
• A contrast CT scan of the abdomen, chest and pelvis is utilised to
▫ assess the extent of disease,
▫ the involvement of the contralateral kidney,
▫ the effect on surrounding tissues
▫ the extent of metastatic disease.
• Preoperative tissue diagnosis. Controversy.
▫ In US, primary resection without a prior tissue diagnosis is the routine. The operative and histological
findings then direct the need for subsequent chemotherapy and radiotherapy.
▫ In Europe, preoperative chemotherapy is initiated without a tissue diagnosis.

37. Differential Diagnosis:-
37

38. Staging of Wilms tumour

39. Treatment:-
• Treatment of Wilms tumor is nephrectomy and chemotherapy with or without
radiation therapy.
• The timing of Wilms tumour surgery relative to biopsy and/or chemotherapy remains
controversial.
▫ The North American approach recommends an upfront nephrectomy (confirming tissue diagnosis)
followed by adjuvant chemotherapy with or without radiation therapy, whereas the
▫ European approach is to make a diagnosis relying predominantly on imaging (sometimes a
biopsy), provide upfront (neoadjuvant) chemotherapy, then nephrectomy of the involved kidney
followed by adjuvant chemotherapy with or without radiation therapy.
1. Tumour nephrectomy is an integral component of successful Wilms tumour
management. By an open and transabdominal approach.
2. Chemotherapy
3. Radiotherapy

40. Prognosis
• Wilms tumours, in contrast to neuroblastoma, are associated with excellent rates of
survival.
• Cure rates for stage I are as high as 95%, and even in those with stage V disease, the cure
rates approach 75%.
• Late recurrence is rare.
• Patients must be followed for the late effects associated with both chemotherapy and
radiotherapy.

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44. 44

46. Hepatoblastoma
• is the most common malignant tumour presenting as a right upper quadrant mass in children less
than 1 year of age.
• Differential diagnoses include
▫ Haemangioendothelioma (the most common benign vascular tumour of the liver in infancy,
typically presenting before 6 months of age)
▫ Mesenchymal hamartoma (a benign tumour that almost exclusively occurs in children under 2 years
of age).
• The mass in an infant with hepatoblastoma is typically large.
• The infant may also present with systemic features such as weight loss, vomiting and anaemia.
• Elevation of the tumour marker serum alpha-fetoprotein in a patient with a liver mass strongly
suggests hepatoblastoma.
• Accurate preoperative imaging is necessary, including ultrasonography, CT scan, MRI and
angiography.
• Operative resection of the lesion, either locally or by lobectomy, remains the main treatment for all
primary liver tumours, but preoperative chemotherapy significantly improves survival.
• There is almost no chance of cure in hepatoblastoma patients without complete resection.

47. KEY POINTS
•A child with an abdominal mass needs immediate clinical assessment and
investigation to exclude malignancy.
•Abdominal masses in toddlers may be huge before diagnosis.
•Ultrasonography is an effective screening test for malignancy.
•A patient with a presumed abdominal tumour needs immediate referral to
the regional surgical and oncology centre.

51. Answers:-
1.1 Hydronephrosis.
1.2 Renal ultrasound, nuclear renal scan ± cystoscopy with retrograde pyelogram to
distinguish pelvi-ureteric junction obstruction from vesico-ureteric junction obstruction.
2.1 Wilms tumour or neuroblastoma, once ultrasound confirms lesion is solid.
2.2 Biopsy/excision and chemotherapy ± radiotherapy.
3.1 Catecholamine measurements (VMA, HMA) in urine, CT scan, bone scan, bone marrow
and FBE; neuroblastoma.
3.2 Prognosis is poor, but some are still curable with chemotherapy and surgery.