Tuesday, January 15, 2008

How to Diagnose Wilm's Tumors


Wilm's tumor is a malignant tumor of the kidneys or neuroblastoma. It is the most common abdominal cancer among children, but the survival rates are in the 80 to 90 percent range. Wilm's tumor is caused by mutations of the genes responsible for kidney development and can be inherited as an autosomal dominant trait. The following steps will show how to diagnose Wilm's tumor.


Difficulty: Challenging



Step One

Detect an asymptomatic abdominal mass as the first sign of Wilm's tumor in 80 percent of cases. One fourth of patients experience abdominal pain or blood in the urine. Less common symptoms include fever, hypotension, urinary tract infections and varicocele.

Step Two

Conduct a physical examination, paying particular attention to patients already diagnosed with conditions associated with Wilm's tumor. These include Beckwith-Wiedemann syndrome (BWS) and Wilm's tumor Aniridia Genitourinary Retardation (WAGR) syndrome, which can cause aniridia, malformed genitourinary systems and signs of overgrowth.

Step Three

Perform cytogenetics studies to suggest Wilm's tumor. An 11p13 deletion may be found as in WAGR syndrome and 11p15 may be duplicated as in BWS. The WT1 gene may need to be analyzed if Wilm's tumor is suspected.

Step Four

Run a Computed Tomography (CT) scan to determine the tumor's origin, involvement of the kidney and lymph nodes, and metastasis to the liver.

Step Five

Analyze the suspect tumor histologically to confirm the diagnosis. A triphasic composition of blasternal, epithelial and stromal elements is characteristic for Wilm's tumor. Renal tumors do not have anaplastic changes 90 percent of the time, which predicts a favorable outcome.

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