Kidney Neoplasms

Question 1

What is the most common primary malignancy of the kidney in childhood?

Answer 1

Wilms tumor (nephroblastoma)

Question 2

Name three Wilms-associated disorders.

Answer 2

GU anomalies (including cryptorchidism and hypospadias), hemihyperplasia, and sporadic aniridia

Question 3

Name three Wilms-associated syndromes.

Answer 3

WAGR syndrome, Beckwith-Wiedemann syndrome, and Denys-Drash syndrome.

Question 4

List the conditions in WAGR syndrome.

Answer 4

Wilms tumor, Aniridia, GU abnormalities, intellectual disability (mental Retardation)

Question 5

List the findings in Beckwith-Wiedemann syndrome.

Answer 5

Organomegaly, macroglossia, omphalocele, hemihyperplasia, and Wilms tumor.

Question 6

List the findings in Denys-Drash syndrome.

Answer 6

Wilms tumor, nephropathy, male undervirilization

Question 7

What genes have been implicated in the development of Wilms tumor?

Answer 7

Wilms tumor suppression gene (WT1) at chromosome 11p13 and another gene at 11p15.5

Question 8

Describe the favorable (and more common) histology associated with Wilms tumor.

Answer 8

The tumor is usually triphasic - made up of epithelial, blastemal, and stromal elements.

Question 9

What is considered unfavorable histology in Wilms tumor? What is its associated incidence and prognosis?

Answer 9

Anaplasia is a poor prognostic finding. It accounts for only 10% of cases, but 60% of deaths.

Question 10

What is the most common presentation for Wilms tumor?

Answer 10

The median age for diagnosis is about 3 years of age, with the most common sign being an asymptomatic abdominal or flank mass. About 50% of patients have nausea, vomiting, or abdominal pain. HTN occurs in 25% of patients due to tumor impingement on the renal artery.

Question 11

What is the typical initial evaluation for a child suspected of having a Wilms tumor?

Answer 11

CXR, CT abdomen and chest, US, and ECHO.

Question 12

What is the mainstay of therapy for unilateral Wilms tumor?

Answer 12

Nephrectomy with removal of the primary tumor. Most patients then receive postsurgical chemotherapy.

Question 13

T/F: Most unilateral Wilms tumor patients receive chemotherapy.

Answer 13

True

Question 14

When is presurgical chemotherapy indicated in patients diagnosed with Wilms tumors?

Answer 14

If there is extensive tumor thrombus to the intrahepatic vena cava or there is thrombus more proximally to the right atrium or the primary tumor is deemed unresectable without significan surgical morbidity.

Question 15

What chemotherapeutic agents are commonly used in the treatment of Wilms tumor?

Answer 15

Vincristine, actinomycin D, and doxorubicin.

Question 16

When is radiation therapy used in patients diagnosed with Wilms tumor?

Answer 16

Abdominal radiation is useful in patients with Stage 3 or 4 disease. Whole-lung irradiation is a possibility for those with pulmonary metastatic lesions.

Question 17

What is a nephroblastomatosis and what does it signify?

Answer 17

It is a term signifying diffuse nephrogenic rests (precursor lesions to Wilms tumor) throughout one or both kidneys. They occur in all bilateral and ~1/3 unilateral Wilms tumors and merit careful follow up with US or MRI.

Question 18

What is a mesoblastic nephroma and how is it managed?

Answer 18

It is the most common congenital renal disorder, presenting as a firm, solitary mass of the kidney. It looks like a leiomyoma, is benign, and resection is curative.

Question 19

Describe the typical presentation and management of renal cell carcinoma.

Answer 19

It is very rare in children but occasionally occurs in adolescence. It presents with abdominal pain and hematuria. Complete resection can be curative, but those with residual disease or metastases have poor prognosis because it doesn’t respond well to therapy.