Work-up & Staging

Question 1

What is the typical workup for an abdominal mass of unclear etiology in a child?

Answer 1

Abdominal mass workup: H&P (focusing on congenital defects), labs, UA (including urinary catecholamines), abdominal US, CXR, and CT C/A/P

Question 2

What is the recommended 1st-line imaging modality for an abdominal mass?

Answer 2

US is the recommended 1st-line study for imaging the abdomen.

Question 3

Pts with what histologic subtype(s) require bone scan?

Answer 3

Clear cell

Question 4

With a Dx of Wilms, what 2 chest imaging modalities can be employed for staging purposes?

Answer 4

Both CXR and CT are used for chest imaging. Lesions seen on CT but not visible on CXR may be treated more conservatively than lung mets visible on CXR.

Question 5

Pediatric pts with what renal tumors need BM Bx?

Answer 5

Pts with clear cell and rhabdoid require BM Bx.

Question 6

Pediatric pts with what renal tumors require MRI of the head as part of their workup?

Answer 6

Rhabdoid: 10%–15% will have PNET in brain (atypical teratoid rhabdoid tumors)

Clear cell: to r/o brain mets

Question 7

What is the typical appearance of WT on CT?

Answer 7

Large round mass with pseudocapsule usually without calcifications. Less likely to cross midline than NBs.

Question 8

Under what circumstances should Bx be performed?

Answer 8

Do not Bx unless the tumor is unresectable or bilat Dz. If Bx is necessary, use a post approach to avoid contaminating the abdomen.

Question 9

On what issues should the surgeon comment at the time of Sg?

Answer 9

Involvement of regional nodes, opposite kidney, peritoneum, liver, renal vein/IVC. Also, if there is tumor spillage and if it is confined to the ipsi flank.

Question 10

What % of pts present with each of the features summarized in this table?

Answer 10

Question 11

What are some common sites of mets?

Answer 11

Lung (80%) → liver → bone, brain (clear cell), LN (outside abdomen and pelvis)

Question 12

How commonly is calcification seen in Wilms?

Answer 12

Calcification is seen in 10%–15% of cases but is seen in 85% of NB cases.

Question 13

How many stages are there in Wilms?

Answer 13

There are 5 stages in Wilms.

Question 14

Summarize the staging of WT.

Answer 14

I: (40% of pts): limited to kidney

II: (20%): extension to outside capsule, vessel involvement >2 mm

III: (20%): R1–R2 resection, +LN, local spillage or diffuse peritoneal spillage, Bx (including FNA), +implants, +margin, transected tumor thrombus, piecemeal resection, unresectable tumor

IV: (10%): hematogenous mets or LN+ outside the abdomen/pelvis

V: 4%–8%): bilat Dz; each side staged independently

Question 15

Is adrenal involvement considered a met?

Answer 15

No. Adrenal involvement is considered local extension.

Question 16

Which stage of favorable and unfavorable histology Wilms tumor patients requires radiotherapy?

Answer 16

Surgery and adjuvant chemotherapy (18–24 weeks) are required for all patients (though some centers omit chemotherapy for very low-risk patients (if age <2 year, stage I, favorable histology, and tumor <550 g). According to COG guidelines, radiotherapy is used for stage III–IV favorable histology and stage I–IV unfavorable histology (focal and diffuse anaplasia), and all clear cell and rhabdoid tumors (with the exception of stage I CCSK after central review on studies). Radiation therapy should start by postoperative day 10 if possible, but no later than day 14.