Links To PedsCases’ “Approach to Abdominal Mass Part 1 With Additional Resources

Here is a list of all the types of resources available on PedsCases, Categories.

In this post I link to and excerpt from PedsCases’ Approach to Abdominal Mass Part 1 by Kieran.Purich Oct 15, 2017 [Link to the podcast] [Link to the script].

Here are excerpts:

Differential Diagnosis [Of Pediatric Abdominal Mass]

[Differential Diagnosis should be broken down into the following categories:]

  • Renal
    • In newborns, renal causes make up around half of all cases of abdominal masses.
      These renal etiologies can be broken down into malignant, and non-malignant

      • The most common causes of renal abdominal mass in infants are
        nonmalignant – specifically hydronephrosis followed by polycystic kidney disease
      • The most common renal malignancy seen in children is Wilms’ tumor or nephroblastoma
  • Hepatobiliary
    • Hepatobilliary causes make up 5-6% of pediatric intra-abdominal masses.
      • The most common pediatric malignancy involving the liver is hepatoblastoma, which generally
        presents between 1 and 3 years of age.
      • Benign hepatobilliary causes include:
        hemangiomas, liver cysts and congenital bile duct anomalies.
  • Adrenal gland
    • They host a subset of tumours known as
      neuroblastomas, which are the most common extracranial solid organ malignancy in
    • We will discuss neuroblastomas in more detail during the second episode of this podcast series.
  • Gastrointestinal causes include:
  • Spleenomegaly
    • Occasionally due to malignant causes such as lymphoma
    • Infectious causes including EBV (mononucleosis), TB and other viral hepatitis,
    • also seen to be enlarged in benign vascular tumors of the spleen
    • Occasionally in cell storage diseases such as gaucher’s disease and sarcoid disease.
  • Pancreatic
    • Pediatric patients rarely present with abdominal masses arising from the pancreas
    • Pancreatic pseudocysts can occur following trauma
    • A primary tumor known as pancreatoblastoma is occasionally seen in the first 10 years of life
  • Genitourinary causes
    • A full bladder secondary to
    • Congenital abnormalities such as urachal cysts
  • Pregnancy
    • Pregnancy must be ruled out in all children of childbearing age
  • Pediatric ovarian causes
    • Ovarian cysts
    • Congenital vaginal obstruction
    • Benign tumors like ovarian teratomas.
    • There are numerous malignant ovarian tumors, which will not be touched on in this podcast.

Finally, Enlargement of any abdominal organ should be considered, including the liver, spleen, kidney and bladder. Some other causes that do not fit into the above categories
are: abdominal hernias, lymphoma, sarcomas, intra-abdominal infection/abscess and hematomas.

Physical Exam:

Start with the patient’s vital signs and weight/height in comparison to their previous growth chart. New onset hypertension can be suggestive of a mass arising from a renal
or adrenal cause. Documented fevers can suggest malignancy or infection. Tachycardia can be related to adrenal tumors or pain.

On abdominal exam you should begin by inspecting the abdomen – does it appear notably distended? Is it asymmetric?

Percussion should be used alongside palpation to assess for hepatomegaly or splenomegaly, which would warrant U/S investigation.


In most cases, the imaging modality of choice is an abdominal ultrasound, which can help to identify the location, vascular supply and characteristics of the mass.

If concerned about constipation abdominal radiographs may be completed in order to rule out obstruction or to look for a transition point in the colon.



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