Nephroblastoma Flashcards
(30 cards)
What is nephroblastoma?
A malignant renal tumor derived from embryonal cells, also known as Wilms’ tumor.
What is the typical age range for nephroblastoma diagnosis?
Typically presents in children between 1 and 4 years of age.
How does nephroblastoma commonly present?
As an abdominal mass, often discovered incidentally during a physical examination.
What are some common symptoms of nephroblastoma?
Vague abdominal discomfort, hematuria, and sometimes hypertension.
What is the significance of the WT1 gene in nephroblastoma?
A mutation in the WT1 gene (on chromosome 11p13) causes some cases of nephroblastoma.
What does the WT1 gene regulate?
The WT1 gene contains genes responsible for the development of the kidney, genitourinary tract, and eyes.
What other genetic abnormalities are associated with nephroblastoma?
Mutations in WT2 (located at 11p15) have been linked to Beckwith-Wiedemann syndrome.
What syndromes predispose individuals to nephroblastoma?
Beckwith-Wiedemann syndrome, Li-Fraumeni syndrome, and Denys-Drash syndrome.
What is WAGR syndrome?
A syndrome associated with nephroblastoma, consisting of aniridia, hemihypertrophy, genitourinary malformations, and mental retardation.
How can nephroblastoma extend into the body?
It can extend into the renal vein and vena cava, and metastasize to lymph nodes and lungs.
How can tumor thrombus be detected?
With an ultrasound study.
What are the two main histological categories of nephroblastoma?
Favorable and unfavorable.
What is favorable histology in nephroblastoma?
Characterized by the presence of blastemal, stromal, and epithelial cells.
What is unfavorable histology in nephroblastoma?
Characterized by anaplasia, clear cell sarcoma, or rhabdoid tumor cells.
What are nephrogenic rests?
Precursor lesions found in 25-40% of kidneys with nephroblastoma, which do not have oncologic potential.
What imaging techniques help diagnose nephroblastoma?
Ultrasound (for tumor thrombus), CT scan (for tumor differentiation, regional adenopathy, and metastasis).
What are common findings on a CT scan for nephroblastoma?
A CT scan is valuable in differentiating Wilms’ tumor from other tumors and in evaluating regional adenopathy, contralateral kidney involvement, and distant organ metastasis.
What are the stages of nephroblastoma according to the National Wilms Tumor Study Group (NWTSG)?
Stage I: Tumor limited to the kidney and completely excised.
Stage II: Tumor extends through the renal capsule but is completely removed.
Stage III: Residual tumor confined to the abdomen, lymph node involvement, diffuse peritoneal contamination, or positive resection margins.
Stage IV: Hematogenous metastases present.
Stage V: Bilateral renal involvement.
What is the standard surgical procedure for nephroblastoma?
A radical nephrectomy with lymph node sampling.
When is nephron-sparing surgery considered?
In children with a solitary kidney or bilateral Wilms’ tumor.
What is the typical treatment for nephroblastoma?
Chemotherapy and surgery.
What chemotherapy drugs are used in nephroblastoma treatment?
Vincristine and dactinomycin, with the addition of doxorubicin or radiation therapy.
What is the goal of preoperative chemotherapy?
To induce tumor shrinkage and allow for more complete resection.
What factors influence the prognosis of nephroblastoma?
Tumor spread, completeness of excision, and histological appearance.
