weekly_question 4/12/2022

[Admin]

A four-year old female presents with a unilateral five cm renal tumor confined to the upper pole of the left kidney. Computerized tomography reveals multiple lesions in both lungs. She is otherwise asymptomatic. The next best step in management of this patient with a metastatic renal tumor is

A open renal and lung biopsy.

B left partial nephrectomy.

C intraoperative biopsy of left tumor followed by nephrectomy if Wilms tumor.

D renal biopsy followed by adjuvant chemotherapy.

E left total nephroureterectomy with lymph node sampling.

[Admin]

correct answer
E left total nephroureterectomy with lymph node sampling.

Lung metastasis with a unilateral Wilms tumor (WT) does not preclude an upfront resection of the abdominal tumor. In WT, staging consists of an abdominal (local) stage and a disease stage. Local stage determines the treatment of the abdomen and disease stage is the overall burden of disease including lung treatment. This child can be stage II locally yet have overall stage IV disease. Although she will need three drug chemotherapy and lung radiation due to metastatic pulmonary disease, if a biopsy was done this would locally upstage the child and mean that she would additionally need abdominal radiation. A five cm tumor is small, poses limited risk of rupture, and is easily removed.

Partial nephrectomy is contraindicated in almost all children with unilateral WT for several reasons. Although technically feasible, the WT develop from clonal expansion of nephrogenic rests which are multifocal within the kidneys of most children with WT. Thus, premalignant lesions could be left behind. Second, the rate of renal failure at forty years in patients with WT is 0.9%. Thus, renal failure is not a long term complication and there is a high risk of positive margins when doing partial nephrectomies which exposes the child to increased chemotherapy, radiotherapy and their late effects.

Partial nephrectomies are only indicated in children with bilateral WT, a single kidney or high risk patients with unilateral disease (such as Beckwith-Wiedemann syndrome). An intraoperative biopsy followed by nephrectomy at the same operation if found to be WT is inappropriate as this would upstage the child to stage III. Biopsies are only needed if the tumor is unresectable.

There are clinical situations where it is agreed that primary nephrectomy is contraindicated. These are when there is extension of tumor thrombus above the level of the hepatic veins the tumor involves contiguous structures whereby the only means of removing the kidney tumor requires removal of the other structures (e.g. spleen, pancreas, colon but excluding the adrenal gland), bilateral tumors, tumor in a solitary kidney, pulmonary compromise due to extensive pulmonary metastases.

[Ismail]

E

[Dr Ali]

E

[Admin]

correct answer
E left total nephroureterectomy with lymph node sampling.

Lung metastasis with a unilateral Wilms tumor (WT) does not preclude an upfront resection of the abdominal tumor. In WT, staging consists of an abdominal (local) stage and a disease stage. Local stage determines the treatment of the abdomen and disease stage is the overall burden of disease including lung treatment. This child can be stage II locally yet have overall stage IV disease. Although she will need three drug chemotherapy and lung radiation due to metastatic pulmonary disease, if a biopsy was done this would locally upstage the child and mean that she would additionally need abdominal radiation. A five cm tumor is small, poses limited risk of rupture, and is easily removed.

Partial nephrectomy is contraindicated in almost all children with unilateral WT for several reasons. Although technically feasible, the WT develop from clonal expansion of nephrogenic rests which are multifocal within the kidneys of most children with WT. Thus, premalignant lesions could be left behind. Second, the rate of renal failure at forty years in patients with WT is 0.9%. Thus, renal failure is not a long term complication and there is a high risk of positive margins when doing partial nephrectomies which exposes the child to increased chemotherapy, radiotherapy and their late effects.

Partial nephrectomies are only indicated in children with bilateral WT, a single kidney or high risk patients with unilateral disease (such as Beckwith-Wiedemann syndrome). An intraoperative biopsy followed by nephrectomy at the same operation if found to be WT is inappropriate as this would upstage the child to stage III. Biopsies are only needed if the tumor is unresectable.

There are clinical situations where it is agreed that primary nephrectomy is contraindicated. These are when there is extension of tumor thrombus above the level of the hepatic veins the tumor involves contiguous structures whereby the only means of removing the kidney tumor requires removal of the other structures (e.g. spleen, pancreas, colon but excluding the adrenal gland), bilateral tumors, tumor in a solitary kidney, pulmonary compromise due to extensive pulmonary metastases.