Links To PedsCases’ “Approach to Abdominal Mass Part 2 With Links To Additional Resources

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

In addition to the material in this post, please review PedsCases’ Approach to Abdominal Mass Part 1 by Kieran.Purich Oct 15, 2017 [Link to the podcast] [Link to the script].

In this post I link to and excerpt from PedsCases’ Approach to Abdominal Mass Part 2 by Kieran.Purich Oct 15, 2017 [Link to the podcast] [Link to the script].

Here are excerpts:

In this podcast we will discuss two specific pediatric malignancies – one of renal origin known as Wilms’ Tumor*, as well as neuroblastoma** – a tumor often associated with the
adrenal gland.

*This link is to the article on Wilm’s Tumor of March 19, 2019 from

**This link is to the article on neuroblastoma of July 12, 2017 from In addition, please see the article of October 9, 2019 Pediatric Neuroblastoma from

So what exactly is Wilms’ tumor?

Wilms’ tumor, also called nephroblastoma, is the most common renal malignancy in children making up 95% of renal tumors in individuals less than 18 years of age. The incidence is 8 Wilms’ tumors per million children under 15 in the USA per year.

Most Wilms’ tumors are unilateral solitary lesions, however, bilateral involvement and multifocal loci within a single kidney do occur.

How would it present?

Most patients present with an abdominal/flank mass and no other significant signs or symptoms. Other patients may complain of abdominal pain (30-40%), demonstrate
gross hematuria (12-25%), or present with fever and hypertension (25%).

Physical exam

On exam vital signs may show hypertension. On abdominal exam you will feel a firm, smooth mass that is eccentrically located and rarely crosses the midline. One must be very careful to not palpate too aggressively as the renal capsule can be ruptured resulting in tumor spillage. Ensure to look for superficial bruising as acquired Von Willebrand disease* can occur in 4-8% of patients with Wilms’ tumors at diagnosis.

*Link is to the article Acquired Von Willebrand syndrome from The Genetic and Rare Diseases Information Center of The National Institutes Of Health.

Initial Imaging

Abdominal ultrasound is the first test of choice. MRI* or CT* is used secondarily to look for bilateral lesions, metastases and to assess resectability. On imaging Wilms’ tumor typically presents as a hypervascular, solid, heterogeneously echogenic solitary renal mass. Calcification is present in up to 20% of cases.

Labs Include

CBC/D, urinalysis, creatinine, electrolytes, liver function tests, serum calcium (high in rhabdoid tumor or mesoblastic nephroma), coagulation studies including VW assay for Von Willebrand Disease.


The 5-year survival rates with multimodal treatment currently approaches 90%.

Now lets move on to neuroblastoma.

What is neuroblastoma?

Neuroblastoma is a term that encompasses multiple tumors arising from neural crest cells destined to be sympathetic ganglion cells. These tumors have potential to secrete catecholamines and can appear in various locations. Tumors within this group can vary from benign to aggressive disease.

Neuroblastoma is the most common extracranial solid tumor of childhood, and is one of the most common childhood malignancies. The median age at diagnosis is 19 months.

Background – This section is from

Neuroblastoma is the most common intra-abdominal malignancy of infancy, the most common cancer in infancy, and the most common extracranial solid tumor of childhood, with an incidence of over 700 cases in the United States every year. [2, 3] Neuroblastoma is the third most common malignancy in children up through 14 years of age, behind acute lymphocytic leukemia and cancers of the brain and central nervous system. [2] It accounts for 7% of pediatric malignancies but for more than 10% of childhood cancer-related mortality. [4]

Neuroblastoma Workup – This section is from

Clinical Presentation

Neuroblastomas can present in numerous ways. The adrenal gland is the most common site for occurrence (40%). Followed by the abdomen (25%) and the thorax (15%). These tumors can also arise from cervical and pelvic ganglia. For our podcast we will focus on those, which present as an abdominal mass

Parents may comment on a newfound fixed, firm abdominal mass. (2/3 of primary neuroblastomas arise in the abdomen) which may be accompanied by abdominal pain, constipation, back pain, scoliosis, bladder dysfunction, fever, weight loss, and bone pain. Far less often, patients may demonstrate flushing and sweating due to the tumor’s secretion of catecholamines.

Metastasis occurs by hematogenous and lymphatic spread, often affecting bone, bone marrow, skin and the liver. This may cause pain, blood count abnormalities, fever, bone pain, periorbital ecchymosis, ptosis, proptosis, a diffuse bluish red non-tender
subcutaneous rash termed “blueberry muffin baby”, heterochromia iridis (different colors of iris or portions of iris), nasal obstruction and/or limping.


As with most abdominal masses the initial study should be an ultrasound and if the results are concerning for malignancy an urgent consultation with a pediatric oncologist and or a pediatric surgeon is warranted. CXR may also be completed to
ensure there is no thoracic disease.

In order to evaluate lymph node involvement, presence of metastases, and resectability a CT or MRI will be ordered by the oncologist or surgeon.


Since neuroblastoma is a heterogenous entity it is difficult to give a generalized prognosis. They are staged using the International neuroblastoma staging system (INSS) and this is a large predictor of prognosis. In general prognosis is better in
younger patients with localized disease. As children age the 5-year survival steadily decreases (83% at 1 year and 40 % at 5-9 years).

As mentioned previously, many of these treatments have long-term effects. For neuroblastoma these include: renal issues, poor growth, thyroid dysfunction, infertility and secondary malignancies. Long-term followup is recommended at a Childhood Cancer Survivor Program.

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