Wilms Tumor

00:01 In this lecture, we will review the Wilms tumor, which is a renal tumor in children.

00:06 This is basically a kidney tumor arising from pluripotent embryonic renal precursor cells.

00:12 This represents about 5 to 7% of pediatric malignancies diagnosed each year and its peak age of diagnosis is around 2 to 3 years of age.

00:24 So, this tumor is associated with multiple genetic syndromes including the Beckwith-Wiedemann syndrome, as well as WAGR syndrome which is Wilms, Aniridia, GU abnormalities, and mental retardation.

00:38 Also, it's associated with the Denys'Drash syndrome which is pseudohermaphroditism and degenerative renal disease and the WT1 and WT2 gene mutations which are vital to kidney development and this represents about 20% of cases.

00:56 So, to diagnose the Wilms tumor, we'll do a good history, a physical exam, and get some imaging.

01:02 From a historical perspective, there's generally a history of a painless abdominal mass.

01:08 It doesn't usually hurt.

01:09 Patients may have nausea or vomiting.

01:11 They may experience weight loss.

01:13 They may have lethargy and fatigue.

01:15 They may notice abdominal pain or distension but it'll be non-specific, not on the mass, and what's key is they'll often have gross hematuria.

01:25 So, a child with gross hematuria at the age of 2 to 3, that's something we're worried about.

01:30 Next, we'll do a physical exam.

01:32 So, this should be a painless, palpable, firm, fixed abdominal mass.

01:37 It is a friable tumor however, so you should be cautious when palpating the abdomen if you know this patient has a Wilms or if you suspect it might be a Wilms as with rough palpation, the tumor may rupture.

01:50 The patient may also have hypertension as associated with this disease.

01:56 They may have pallor or they may have a varicocele or an inguinal hernia.

02:02 Additionally, they may have abdominal vein distension and you may see potential stigmata of those other genetic syndromes we mentioned before.

02:11 Next, if we suspect the disease, we'll do some diagnostic imaging.

02:17 First, regarding lab findings, we'll often get a CBC with differential.

02:22 What's unique about this tumor is patients may present with polycythemia from increased epo expression from the tumor.

02:31 Patients will also have hematuria, so a urinalysis is indicated, and then we'll generally do a biopsy to confirm the diagnosis.

02:39 We would usually image them prior to biopsying to verify the presence of a tumor and typically what we'll see is something like this, which is a large tumor showing characteristic mixed tissue densities, cystic and solid, and arising from the kidney and enveloping a remnant of normal renal tissue.

02:58 So, it's generally found on imaging though with a renal ultrasound.

03:05 That's usually our first choice for how we image these patients and then, we'll get a CT scan of the chest, abdomen and pelvis for staging purposes and for further characterizing the lesion, although ultrasound is usually how we first make the diagnosis.

03:20 Then, we will provide multimodal therapy depending on the stage and histology of the tumor.

03:27 So we will usually surgically resect these, we may do radiation, and we may also do chemotherapy.

03:35 Generally, the prognosis for this disease is very good depending on stage of disease.

03:41 So, for stage I disease, event-free survival is upwards of more than 95%.

03:48 It has a great prognosis.

03:49 Stage II or III, 80 to 95%, and even stage IV disease has a 75% event-free survival.

03:57 So that's my review of Wilms tumor in children. Thanks.