Abdominal tumors in children
Abdominal tumor ≠ abdominal neoplasm
In neonatal and infantile period the majority of
palpable masses in abdomen are anomalous or
enlarged organs .
Congenital abnormalities of kidneys are the
cause of 55% of all unilateral and 90% of bilateral
abdominal masses in newborns and infants
Newborns and infants (< 2 year of life)
Unilateral abdominal tumours:
• Kidneys – 55%
hydronephrosis
multicystic dysplastic kidney
mesoblastic nephroma
• Retroperitoneal cavity (besides kidneys) – 15%
adrenal haematoma
neuroblastoma
teratoma
• Gastrointestinal system – 15%
duplications
Bilateral abdominal masses:
• Genital system – 10%
• Kidneys (90%)
ovary cyst
polycystic kidneys diseases
Hydromethrocolpos
ADPKD, ARPKD
• Liver – 5%
hepatoblastoma
Toddlers and older children
(>2 year of life)
• Kidneys (45%)
Wilms tumour (nephroblastoma)
hydronephrosis
• Retroperitoneal cavity (40%)
(adrenal glands, autonomic ganglions, lymph nodes)
neuroblastoma
teratona
lymphoma
• Gastrointestinal system (15%) - liver, splen, bowels
lymphoma
duplications
hepatoblastoma
Retroperitoneal cavity
BENIGN TUMOURS:
Adrenal -
haematoma
Kidney enlargement –
hydronephrosis, abscess, renal
veins thrombosis
MALIGNANCIES:
Renal –
Wilms tumour
Lymph nodes –
lymphoma
adrenals and
autonomic ganglions –
neuroblastoma
Diagnostic algorithm in children with palpable
abdominal tumour
USG and plain abdominal rentgenogram – cystic mass:
KIDNEYS
ADRENALS
LIVER
PANCREAS
Voiding
cystoureterography
control usg
(in 2-3
weeks)
scyntygraphy
control usg
scyntygraphy/u
rography
computed
tomography
computed
tomography
(if necessary)
hydronephrosis cysts post
/ multicystic
haematoma
dysplastic/
ADPKD
cysts/ ADPKD post-traumatic
pseudocyst
Diagnostic algorithm in children with
palpable abdominal tumour
USG and plain abdominal rentgenogram – solid mass:
KIDNEY
ADRENAL
LIVER
LYMPH
NODES
computed
tomography
Bones
scintigraphy
computed
tomography
computed
tomography
Chest
Catecholamine α- fetoprotein
radiogram/
level
level
chest computed
tomography
Wilms tumour/ neuroblastoma hepatoblastoma lymphoma
mesoblastic
nephroma in infants
Abdominal tumors in children
Hydronephrosis in infant
bilateral,
more pronounced on the right
Abdominal tumors in children
Unilateral hydronephrosis
Abdominal tumors in children
Newborn – adrenal haematoma
Abdominal tumors in children
ADRENAL HEMATOMA
- detection by ultrasound (hypoechoic mass above the upper pole of the kidney, mixed echogenicity
with hyperechoic areas are possible)
- follow up examination to demonstrate volume regression
- calcifications in follow-up studies
- difficult to distinguish from neuroblastoma (laboratory findings- catecholamine metabolites in
urine can help)
- MRI or CT is not necessary in early detection after birth. Only in suspicious neuroblastoma for
any other reason, is further imaging necessary. If volume regression is absent, MRI becomes
necessary. Hyperintense T1w signal is indicative of hemorrhage.
Abdominal tumors in children
Autosomal recessive
policystic kidney disease
urography:
bilateral massive
enlargement of kidneys
Abdominal tumors in children
Autosomal recessive
policystic kidney disease CT
Abdominal tumors in children
WILMS tumour
Case 1:
This well 5-year-old child presented with a left-sided abdominal mass. Ultrasound
revealed a large rounded soft tissue mass arising from the kidney. A CT examination was
performed .
• What are the imaging features shown?
• What are the differentiating features that
allow a provisional diagnosis to be made?
• What other investigation should be
performed?
• post contrast CT shows a well defined soft tissue mass in the left upper quadrant
there is normal enhancing renal tissue inferior to the mass
there is some displacement of the surrounding structures but no encasement
there is no visible calcification
• the diagnosis of a Wilm’s tumour is made upon the age of the child, the fact that the
child is relatively well, the tumour is displacing surround structures rather than
encasing them and there is an absence of calcification seen on the CT examination.
• the staging Wilm’s tumour is open to debate. In some centres the presence of chest
metastases is determined by a chest X-ray while other centres may perform chest
CT. With all abdominal imaging is important to stage the tumour and in particular to
look for the presence of tumour spread of the renal vein and into the inferior vena
cava.
Abdominal tumors in children
Cystic nephroblastoma
WILMS tumour
Abdominal tumors in children
NEPHROBLASTOMA (WILMS’ TUMOUR)
 is the most common renal tumour in childhood
 occur mainly in children of less than 5 years (peak incidence between 2 and 5 years of age)
 asymptomatic, occasionally fever, pain and hypertension may be present
 preferred locations for metastases are the locoregional lymph nodes and the lung (‘cannonball’
metastases). Liver metastases are possible. Other distant metastases, e.g. in the skeletal system,
are rare.
 in the first 6 months of life, mesoblastic nephroma occurs more often than Wilms’ tumour.
Abdominal tumors in children
NEPHROBLASTOMA (WILMS’ TUMOUR)
US is the fundamental imaging method
MRI preferred for local tumour extension and abdominal metastases
- homogeneous or inhomogeneous renal mass (bilateral involvement in 10% of cases)
- displacement of neighbouring anatomical structures
- echogenic tumour thrombus in renal vein or inferior vena cava (as the tumor often grows directly
into the renal veins or IVC)
- lymph node enlargement
- tumour bleeding with central fluid/sedimentation levels
- cystic tumours with tumour parenchyma are found in the case of cystic nephroblastoma
Abdominal tumors in children
NEPHROBLASTOMA (WILMS’ TUMOUR)
• MR
- hypointense pseudocapsule in T2w sequences
- in T2 hyper- and T1 hypointensive renal mass with displacement of other organs
- hyperintense tumour thrombus in hypointense vessel signal in T2w sequences
- contrast enhancement of residual renal parenchyma, contrast enhancement of vital tumour areas,
hypointense tumour necrosis
- hyperintensive bleeding in the tumour in T1w sequences
• CT
- hyperdense areas in case of bleeding in native scans
- calcifications in about 14% of nephroblastomas
- inhomogeneous enhancement after contrast administration
Abdominal tumors in children
Adrenal neuroblastoma
Case 2:
A 2-year-old child presented with a large intra-abdominal mass. There was associated
vomiting and weight loss. A CT and nuclear medicine study were performed.
• What are the CT findings?
• What is the nuclear medicine study and what does it show?
• What is the overall diagnosis?
• the CT examination shows a large abdominal mass that is calcified and encases the
great vessels. These are the imaging features of a neuroblastoma
• the nuclear medicine study is a meta-iodo-benzyl-guanidine (MIBG) study.
An MIBG is used to detect skeletal metastases in children with neuroblastoma(MIBG
as an analogon of catecholamine precursors is taken up in neuroblastoma and other
neuro-endocrine tissue.
Normally the skeleton should have no areas of increased activity. In this case
there is marked uptake seen at the ends of the long bones indicting skeletal
metastases. There is also activity in the centre of the abdomen within the primary
tumour.
• normal activity on an MIBG scan is seen within the salivary glands, spleen, liver and
myocardium.This study involved the use of radioactive iodine, as such the thyroid
should be protected by the use of blocking agents. In children this is usually
performed by giving potassium perchlorate 3 days prior to the study
Abdominal tumors in children
NEUROBLASTOMA
 is most frequently diagnosed in infants below the age of 5 years
 originate in neural crest cells of the sympathetic nervous system. Nearly 70% of neuroblastomas
arise in the abdomen. A typical location (about 50%) is the adrenal gland.
 the tumour extends to surrounding tissue by local invasion and to regional lymph nodes.
 metastatic spread in bone marrow, skeleton and liver is frequent. More than 50% of patients have
metastatic disease.
 tumours localized to one side of the abdomen often cross the midline.
 frequently secrete neurogenically derived substances, e.g.catecholamine metabolites or neuron
specific enolase.
Abdominal tumors in children
NEUROBLASTOMA
Primary diagnosis is performed with ultrasound. Imaging studies include local staging with MRI or
CT of the tumour region and chest radiograph. Bone scan and meta-iodobenzylguanidine
(MIBG) scintigram define sites of metastases and demonstrate tumour response to chemotherapy.
Possible findings:
- encasement of retroperitoneal vessels
- ventral displacement of aorta and vena cava
- stippled tumour calcifications
- single tumour of the adrenal gland
- extended tumour mass in the retroperitoneum
- infiltration of adjacent organs
- infiltration into neuroforamen