Bilateral Wilms Tumor Research Articles

Development of Hypertension is Less Frequent after Bilateral Nephron Sparing Surgery for Bilateral Wilms Tumor in a Long-Term Survey

The option of nephron sparing surgery for unilateral Wilms tumor has been debated in the recent literature. This procedure is being used increasingly to preserve kidney tissue and function. However, nephron sparing surgery is feasible only for selected cases, and a higher local relapse rate has been observed. Moreover, a significant reduction of nephrons is associated with development of renal hypertension and progressive renal failure. We analyzed outcomes after bilateral partial nephrectomy and unilateral partial plus contralateral total nephrectomy in patients with bilateral Wilms tumor. We analyzed data from the Society of Pediatric Oncology and Hematology database on 22 patients with bilateral Wilms tumor. Kidney size was measured using volumetric analysis of magnetic resonance imaging. Patients were matched with children who had undergone magnetic resonance imaging of the abdomen for other malignancies. Mean kidney volumes after unilateral partial plus total contralateral nephrectomy (66.9 cm(3)) were significantly greater than the reference kidneys (p = 0.028), whereas controls were equal to the bilateral partial nephrectomy group (49.7 cm(3), p = 0.959). Total kidney volume was significantly larger after bilateral partial nephrectomy (102.1 cm(3)) vs unilateral partial plus total contralateral nephrectomy (66.9 cm(3), p = 0.0338). Eight patients (66.7%) had renal hypertension after unilateral partial plus total contralateral nephrectomy but only 2 (20%) after bilateral partial nephrectomy (p = 0.043). Overall survival and relapse rates were equal between the groups and did not correlate with unfavorable histology. Our findings suggest that patients with bilateral Wilms tumor benefit from bilateral nephron sparing surgery. Hypertension is less common after bilateral partial nephrectomy, and rates of local relapse or disease associated death are distributed equally between the groups.

Bilateral Wilms tumors treated according to the Japan Wilms Tumor Study Group protocol

The introduction of multimodal therapy has improved the survival rate of bilateral Wilms tumors (BWT); however, the results are still not satisfactory in terms of the renal preservation. To establish a new treatment strategy for BWT, we reviewed the results of the cases registered in the Japan Wilms Tumor Study Group (JWiTS). This analysis concerned patients with synchronous BWT registered in the JWiTS between 1996 and 2011. In these patients, the management of BWT included initial tumor resection or biopsy followed by chemotherapy. The details of the treatments and outcomes were analyzed. Among the 355 cases registered in the JWiTS database, 31 (8.7%) had BWT. They were 16 males and 15 females with a mean age of 15.5 months. Preoperative chemotherapy was performed in 24 cases. Bilateral nephron-sparing surgery (NSS) was achieved in 10 of 28 cases (36%). All of the cases were of favorable nephroblastoma without anaplasia, and a WT1 mutation was detected in 21 of the 27 cases (78%) examined. The 5-year overall survival was 92.6%; however, 10 children (40%) developed impaired renal function and three of them developed renal failure. The long-term survival rates for patients with synchronous BWT have improved. However, more than half of patients receive nephrectomy. The protocol should be changed to improve the rate of preservation of the renal parenchyma. Preoperative chemotherapy should be performed to shrink the tumors in every case, and subsequent NSS should be carried out after a central imaging evaluation.

The management of bilateral Wilms tumor.

Wilms tumor (WT) is the most common malignant renal tumor in childhood. Approximately 5-7% of WT patients present with bilateral disease, either synchronously or metachronously. Bilateral WT usually occurs in younger children and more often in girls. Management of a child with bilateral WT is very challenging. In contrast to unilateral WT, there has not been uniform agreement about the therapeutic strategy in the management of bilateral WT. As surgery is a critical component in the treatment of WT, the aim is to achieve a high cure rate while maintaining adequate long-term renal function in patients with bilateral WT. In the past, radical surgical procedures which lead to the patients on dialysis have been traditionally recommended in these patients. After several multicentre trials, bilateral biopsies followed by pre-operative chemotherapy and then renal salvage surgery have been recommended. The management of bilateral WT has evolved from primary surgical extirpation to kidney-preserving resection after preoperative chemotherapy. Preoperative chemotherapy often results in significant reduction in tumor size, thereby facilitating subsequent renal salvage. The analysis of children with bilateral WT shows that preservation of renal parenchyma is possible following initial preoperative chemotherapy. Only centers with experience in bilateral WT should treat the cases with bilateral WT to provide optimal treatment.

Management and outcomes in massive bilateral Wilms' tumors.

Purpose:To evaluate the outcome of children with bilateral Wilms’ tumor (BWT) treated on All India Institute of Medical Sciences-Wilms Tumor-99 (AIIMS-WT-99) protocol.Materials and Methods:All children with BWT, registered in our solid tumor clinic from August 1999 through December 2010 were included.Results:Of the 178 fresh cases of Wilms Tumor (WT) treated during this period, 11 (6.2%) had bilateral involvement. All patients except one (12 and 3 cm), had massive bilateral tumors of more than 10 cm on each side. There were eight boys and three girls in the age range 6–30 months. One patient had Denys-Drash syndrome. Twenty renal units were operated upon (12 tumorectomy, five partial nephrectomy, and three nephrectomies), while one patient with inferior vena cava (IVC) thrombus died of renal failure. Tumor spill occurred in three units, lymphnode was positive in two patients. Local recurrence occurred in four patients (six of 18 renal units (33%)—two bilateral and two unilateral). There was one recurrence in the liver that was treated with radio-frequency ablation. The 5-year overall survival (OS) was 90% (95% confidence interval (CI) = 50.8–98.6) and the relapse free survival (RFS) was 38% (95% CI = 6.1–71.6).Conclusion:Massive BWT respond poorly to preoperative chemotherapy, are often not amenable to partial nephrectomy/tumorectomy and have a higher local recurrence rate, giving a poor RFS.

Ovarian thecal metaplasia of the adrenal gland in association with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome associated with increased risk to develop malignancies including adrenocortical carcinoma. Ovarian thecal metaplasia of the adrenal gland is a rare tumor-like mesenchymal lesion in BWS patients that lacks detailed radiological description. We report a 17-year-old female patient with BWS, associated with bilateral Wilms tumor, hepatic hemangiomatosis, pancreatic neuroendocrine tumor, and a phyllodes tumor of the right breast. Surveillance abdominal ultrasound identified a right adrenal mass that was further characterized by computed tomography and magnetic resonance imaging. Radiologically, this mass displayed features that overlap with adrenocortical carcinoma and pheochromocytoma but after pathological examination this proved to be an ovarian thecal metaplasia of the adrenal gland. Adrenal masses in BWS should raise the suspicion for adrenocortical carcinoma though other adrenal tumors including ovarian thecal metaplasia can be seen in these patients.

Repeat nephron-sparing surgery for children with bilateral Wilms tumor

BackgroundRenal insufficiency is a significant complication of Wilms tumor treatment in the 5% with bilateral disease. Nephron-sparing surgery (NSS) is recommended after neoadjuvant chemotherapy initially. However, the role of NSS in recurrent disease is unknown. We reviewed our experience to assess the feasibility and oncologic and functional outcomes of repeat NSS for children with recurrent disease. MethodsA retrospective review was performed of all children treated at our institution for bilateral, favorable histology (FH) Wilms tumor. Patients undergoing repeat NSS for locally recurrent disease were identified. The outcomes evaluated included tumor recurrence, renal function, and patient survival. ResultsSince 2001, 36 children with bilateral FH Wilms tumor have been treated at our institution. Eight patients (22%) underwent repeat NSS for locally recurrent disease. Two patients had a second local recurrence and underwent a third NSS. Six patients are alive without disease (75%) with an average follow-up of 4.5years. Two patients have died, each with blastemal-predominant histology at repeat NSS. The surviving patients have normal renal function, although two patients require medical management of hypertension. ConclusionsOur experience suggests that repeat NSS for local recurrence of FH bilateral Wilms tumor is feasible and affords acceptable oncologic outcome with preservation of renal function. However, more aggressive therapy may be required for patients whose recurrence has blastemal-predominant histology, given the poor outcome for these patients in our series.

Margin status and tumor recurrence after nephron-sparing surgery for bilateral Wilms tumor

PurposeNephron-sparing surgery (NSS) has been advocated for patients with bilateral Wilms tumor (BWT). We sought to determine whether margin status impacted local tumor recurrence. MethodsA retrospective review of patients undergoing NSS for BWT from November 1999 to March 2009 at our institution in which local recurrence rates based on margin status were compared. ResultsOf 21 patients, five (23.8%) had positive margins. These and 2 (9.5%) with focal anaplasia received flank XRT. Seven (33%) patients developed recurrent disease, a mean of 18.0 (range 1.3–39.9) months after NSS. Recurrence rates were similar in patients with positive and negative margins (1/5 [20%] vs 6/16 [37.5%]; p=0.47). Hypertension occurred more frequently in patients who received XRT (57.1% vs 28.6%). At a median follow-up of 28.6months (range 5.2–142.3), 19 patients are alive, without evidence of disease; one patient (with a positive margin at initial NSS) died of metastatic anaplastic WT and another died of a brain tumor. One patient, with multiple risk factors, developed renal failure. ConclusionsIn our experience, local recurrence rates after NSS were not affected by surgical margin status although all patients with positive margins received XRT. These results support the aggressive use of NSS for patients with BWT.

Surgery for wilms' tumor, Does Preoperative Chemotherapy Ease its Surgical Procedure?

Background: The optimal timing of surgery for Wilms' tumor has been debated for many years. It appears dubious whether surgical ease or per operative complications consistently improved after preoperative chemotherapy.
 Materials and Methods: This is a cross section study ,the sample collected from January 2009 to November 2012 .Thirty four patients were selected after informed consent . Patients aged between 10 months and 5 years who were newly diagnosed with Wilms' tumors. including (17) patients with unilateral wilms tumors received immediate nephrectomy without preoperative chemotherapy according to the National Wilms' Tumor Study Group protocol and (16) patients with unilateral Wilms' tumors and one patient with bilateral wilms tumor received delayed nephrectomy or partial nephrectomy following preoperative chemotherapy according to the International Society of Pediatric Oncology( SIOP) WILMS TUMOR 2001/UK Final Version /January 2002 protocol.Objective : To compare the use of immediate nephrectomy versus delayed nephrectomy or partial nephrectomy following neo adjuvant chemotherapy for treatment of non metastatic Wilms' tumor, in terms of surgical morbidity and per operative complications .
 Results: there is significant change in the maximal tumor size (more than 50% reduction in the maximal tumor diameter) was observed in 52.9% of patients receiving pre operative chemotherapy. There is reduction in the complication rate in that patient receiving pre operative chemotherapy. These observed specifically for decreasing residual tumor and tumor spillage episodes. Bilateral partial nephrectomy after neo adjuvant chemotherapy was done for one patient (5.6%) with bilateral wilms tumor. We found significant decrease in the complication rate mainly for those patients with high risk score receiving pre operative chemotherapy rather than those with low risk score.
 Conclusion: We would favor tumor resection when it is possible as early in therapy as is practical and safe, when there is concern about the safety of primary tumor resection the pre operative chemotherapy can be safely initiated.

Hypospadias and Genes Related to Genital Tubercle and Early Urethral Development

We determined whether variants in genes associated with genital tubercle (the anlage for the penis) and early urethral development were associated with hypospadias in humans. We examined 293 relatively common tag single nucleotide polymorphisms in BMP4, BMP7, FGF8, FGF10, FGFR2, HOXA13, HOXD13, HOXA4, HOXB6, SRY, WT1, WTAP, SHH, GLI1, GLI2 and GLI3. The analysis included 624 cases (81 mild, 319 moderate, 209 severe, 15 undetermined severity) and 844 population based nonmalformed male controls born in California from 1990 to 2003. There were 28 single nucleotide polymorphisms for which any of the comparisons (ie overall or for a specific severity) had a p value of less than 0.01. The homozygous variant genotypes for 4 single nucleotide polymorphisms in BMP7 were associated with at least a twofold increased risk of hypospadias regardless of severity. Five single nucleotide polymorphisms for FGF10 were associated with threefold to fourfold increased risks, regardless of severity. For 4 of them the results were restricted to whites. For GLI1, GLI2 and GLI3 there were 12 associated single nucleotide polymorphisms but results were inconsistent by severity and race/ethnicity. For SHH 1 single nucleotide polymorphism was associated with a 2.4-fold increased risk of moderate hypospadias. For WT1 6 single nucleotide polymorphisms were associated with approximately a twofold increased risk, primarily for severe hypospadias. This study provides evidence that single nucleotide polymorphisms in several genes that contribute to genital tubercle and early urethral development are associated with hypospadias risk.

Bilateral Wilms Tumor withTP53-Related Anaplasia

Wilms tumor (WT) with diffuse anaplasia has an unfavorable prognosis and is often (>70%) associated with mutations in the TP53 gene. Although most WTs are unilateral, 5-10% are bilateral, and they are almost always present with nephrogenic rests. The latter are considered a precursor of WT. Two cases of bilateral WTs with nephroblastomatosis, in which anaplastic changes were detected over a period of time, were analyzed using clinical, radiological, histopathological, and molecular-genetic data. TP53 was analyzed by direct sequencing of its full coding sequence and intron-exon boundaries in 11 fragments. DNA was extracted from paraffin-embedded or frozen specimens. High-resolution genomic copy number profiling was carried out by UCL Genomics on the Affymetrix Human Mapping 250K Nsp or Genome-Wide Human SNP Array 6.0 platform. Both cases demonstrated a strong association between the appearance of anaplastic clones and TP53 mutations. Synchronous ganglioneuroma was diagnosed in one case. Our cases are unique as they represent a long disease history and demonstrate the difficulties in managing rare cases of bilateral WT with anaplasia. These cases also emphasize the practical importance of modern molecular-genetic techniques and their clinical application. Moreover, they highlight the issue of the adequate sampling needed in order to gather comprehensive, efficient, and sufficient information about genetic events in a single tumor.

Tumor de Wilms bilateral y cirugía ahorradora de nefronas: reporte de un caso

En este artículo se reporta el caso de una niña de cuatro años de edad, sin antecedentes perinatales o patológicos de importancia, procedente de área rural, en la región nororiental de Colombia, quien ingresó al Hospital Militar Central de Bogotá, Colombia, remitida por un cuadro de cinco meses de evolución que inició con tinte ictérico, pérdida de peso e hiporexia. Posteriormente, distensión abdominal y masa palpable abdominal de un mes de evolución. Por imágenes diagnósticas se documenta tumor de Wilms bilateral, el cual se trata con quimioterapia preoperatoria y nefrectomía parcial bilateral.

Bilateral Wilms Tumor and Early Presentation in Pediatric Patients Is Associated with the Truncation of the Wilms Tumor 1 Protein

To investigate the frequency of constitutional Wilms tumor 1 gene (WT1) abnormalities in children with bilateral Wilms tumor (WT) and the age of tumor onset in patients with a mutation. Eight patients with bilateral WT were studied. High-resolution melting and direct sequencing were used to screen for the WT1 gene. Western blotting was performed to determine whether the identified mutations were associated with expressed truncated WT1 protein. The median age of tumor onset in patients with a mutation in the WT1 was lower (10 months) than in those without a mutation (39 months). Three novel heterozygous nonsense mutations were identified in exon 8 in peripheral blood from 3 individuals, whereas all 3 tumor tissues lacked the wild-type allele. All mutations led to a premature stop codon with truncation of the WT1 protein. In 1 patient, a truncated form of WT1 protein was identified, suggesting that development of the WT may have resulted from expression of an abnormal protein. Four distinct silent single-nucleotide polymorphisms (SNPs) were detected. All 3 patients with a pathogenic WT1 mutation had 2 synonymous SNPs, whereas only 1 of the remaining 5 patients had a single synonymous SNP (P < .05). Bilateral WT are associated with early presentation in pediatric patients and a high frequency of WT1 nonsense mutations in exon 8. Silent SNPs may also be involved in the development of WT.

Synchronous bilateral Wilms tumor

The optimal management of bilateral Wilms tumor (BWT) is challenging, and their survival is lower than for unilateral tumors. This report discusses a large series of BWTs treated in Italy in the last 2 decades. This analysis concerns patients with synchronous BWT registered at Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) centers between 1990 and 2011; details on their treatment and outcome are presented and discussed. Ninety BWTs were registered in the AIEOP Wilms tumor database. Preoperative chemotherapy was given for a median 12 weeks before definitive tumor resection was attempted. Forty-eight percent of the patients had preservation of bilateral renal parenchyma. The proportion of bilateral nephron-sparing surgeries was not higher in the 37 patients initially given doxorubicin/vincristine/actinomycin D (32%) than in the 43 children receiving vincristine/actinomycin D alone (58%). The 4-year disease-free survival rate was 66.5% ± 5% and overall survival was 80% ± 5% for the cohort as a whole. The 4-year disease-free survival (overall survival) for 18 children with diffuse anaplasia or postchemotherapy blastemal-type tumors was 51% ± 13% (62% ± 13%), as opposed to 72% ± 3% (88% ± 4%) for 68 children with a favorable histology (log-rank P = .04 [P = .007]). These results provide further evidence that the optimal duration and choice of drugs for preoperative chemotherapy remain an open question. Outcome remained significantly worse for BWT than for unilateral Wilms tumor. To enable the conservative treatment of as many affected kidneys as possible, only centers with experience in BWT should manage such cases.

Portal Hypertension in Childhood Bilateral Wilms' Tumor Survivor: An Excellent Indication for TIPS

Introduction. Increased pressure in portal venous system is relatively a rare complication after chemoradiotherapy for Wilms' tumor (WT). In paediatric population, feasibility and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in portal hypertension nonresponsive to medical or endoscopic treatment have been recently advocated. We report a case of TIPS positioning in a 15-year-old girl with portal hypertension as a long-term sequel of multimodality therapy in bilateral WT. Case Report. Two-year-old girl was diagnosed for bilateral WT. Right nephrectomy with left heminephrectomy and chemoradiotherapy were performed. At 7 years of age, the first gastrointestinal bleeding appeared, followed by another episode two years later, both were treated successfully with beta-blockers. At 15 years of age, severe unresponsive life-threatening gastroesophageal bleeding without hepatosplenomegaly was managed by TIPS. Reduction of the portosystemic pressure gradient was obtained. Conclusion. TIPS positioning for portal hypertension in long-term tumors' sequel is feasible and could be considered as an additional indication in paediatric patients.

Familial synchronous bilateral teratoid Wilms tumor with elevated alpha-fetoprotein level

Familial Wilms tumor is a rare entity that accounts for only 1–2% of all Wilms tumor cases, with an earlier age of onset and an increased frequency of bilateral tumors. Teratoid Wilms tumor is a variant of nephroblastoma with a predominance of heterologous tissues comprising more than 50% of the tumor volume. Wilms tumor does not usually secrete any specific tumor marker and all teratoid Wilms tumor cases previously reported were sporadic non-secreting neoplasms. Here we describe an infant with familial synchronous bilateral teratoid Wilms tumor whose serum alpha-fetoprotein level was elevated. To our knowledge, this extremely rare type of case is reported for the first time in the literature.

Pathological Review of Wilms Tumor Nephrectomy Specimens and Potential Implications for Nephron Sparing Surgery in Wilms Tumor

Nephron sparing surgery is accepted as standard of care for children with bilateral Wilms tumor or Wilms tumor in a solitary kidney and some study protocols allow nephron sparing surgery in select cases of unilateral Wilms tumor. With the increasing use of nephron sparing surgery in Wilms tumor, we reviewed pathological features from Wilms tumor radical nephrectomy specimens to determine the potential efficacy of a nephron sparing approach. Medical records of children undergoing pre-chemotherapy radical nephrectomy for unilateral Wilms tumor at our institution were reviewed. Ideal candidates for nephron sparing surgery were defined as those having a unifocal mass outside the renal hilum, sparing a third or more of the kidney, favorable histology, no signs of renal sinus or segmental vascular invasion, no metastatic lymph nodes or gross regional disease, and a distinct interface on pathological review between tumor and remaining parenchyma. A total of 78 children at a median age of 3.2 years (range 0.3 to 16.2) underwent pre-chemotherapy radical nephrectomy for unilateral Wilms tumor. Median tumor diameter was 11 cm (range 2.5 to 22). Of these children 36 (46.2%) had tumors sparing a third or more of the kidney and 70 (89.7%) had unifocal tumors. There were 73 specimens (94.6%) that showed favorable histology, and 56 (71.8%) of the specimens had a distinct border between tumor and remaining parenchyma. In total, 19 (24.4%) of the patients reviewed met all of our strict pathological criteria as ideal partial nephrectomy candidates. In a post hoc analysis using strict pathological criteria and accepted surgical oncologic principles, as many as 1 in 4 children undergoing pre-chemotherapy surgery for nonmetastatic, unilateral Wilms tumor have post-resection pathological tumor characteristics favorable for nephron sparing surgery.

Nephron Sparing Surgery for Unilateral Wilms Tumor in Children with Predisposing Syndromes: Single Center Experience Over 10 Years

Unilateral Wilms tumors associated with predisposing syndromes are treated with preoperative chemotherapy followed by surgical resection. We describe our experience with nephron sparing surgery for Wilms tumor in this population at risk for metachronous lesions. We conducted a retrospective review of all children with a predisposing syndrome who underwent nephrectomy for malignancy during a 10-year period (2000 to 2010). Data collected included age, mode of detection, tumor size, treatment, pathology results, followup time and recurrence episodes. From 2000 to 2010, 13 of 75 (19%) patients treated for Wilms tumor were diagnosed with predisposing syndrome(s). Eight patients with unilateral tumors were treated and had a mean age at diagnosis of 27 months (range 7 months to 9 years). Beckwith-Wiedemann syndrome, isolated hemihyperplasia, WAGR (Wilms tumor, Aniridia, Genitourinary abnormalities, mental Retardation) syndrome and isolated 11p13 deletion were the underlying diagnoses in 3, 2, 2 and 1 patient, respectively. All but 2 patients were diagnosed by screening ultrasound and 5 underwent preoperative chemotherapy. Median tumor size at surgery was 2.5 cm (range 1 to 13). Nephron sparing surgery was performed in 6 of 8 patients. Pathological study showed favorable histology Wilms tumor and nephrogenic rests in 6 and 2 patients, respectively. After a mean followup of 36 months (range 6 to 72) no recurrences were documented and all children had normal creatinine levels. Nephron sparing surgery appears safe for patients with unilateral Wilms tumor associated with predisposing syndrome(s), allowing for the preservation of renal function and good oncologic outcomes for the available followup time. If more studies confirm our observation, current recommendations for the surgical treatment of Wilms tumor may need to reemphasize the value of attempting nephron sparing surgery in this patient population.

Living-donor transplantation after excision of unrecognized renal cancer diagnosed after transplant

Published data on kidneys transplanted after resecting small renal cancers during the transplantation surgery are very rare and, to the best of our knowledge, no pediatric cases have been reported in the literature. Our patient was diagnosed with a bilateral Wilms tumor when he was 15 months old. A total bilateral nephrectomy was required to control the disease. Two years later, a human leukocyte antigen (HLA)-identical living-donor transplant from his father was performed. A small mass in the father's left kidney was diagnosed as an angiomyolipoma during the pretransplant donor evaluation. During the surgery, the mass was excised and the kidney implanted. One week later, the pathological study revealed the mass to be a clear cell renal carcinoma. After joint discussion, the urologic and nephrologic teams and the family decided to maintain the transplant, managing the patient with monotherapy based on rapamycin and close ultrasound control. To date, 8 years after transplantation, no signs of malignancy have been detected, and renal function is normal. This is the first reported pediatric case of a living-donor graft with a small renal carcinoma excised in the operating room. No malignancy has been observed in 8 years of follow-up.

Nephron-sparing partial nephrectomy for bilateral Wilms' tumor

PurposePartial nephrectomy is increasingly used in children with bilateral Wilms' tumor (BWT) or contralateral recurrence. Nephron-sparing surgery seeks to achieve complete tumor removal while preserving functional renal parenchyma. Previous series have documented high rates of complications, recurrence, and mortality. MethodsTwelve patients (4 boys and 8 girls aged 9-42 months) with BWT or contralateral recurrence were treated at our institution with unilateral or bilateral partial nephrectomy. Preoperative imaging, operative notes, and pathology reports were reviewed. Outcomes analyzed included complications, recurrence, readmission rate, postoperative glomerular filtration rate (GFR), and survival. ResultsAll patients underwent successful nephron-sparing resection using standard techniques, with only 2 patients requiring unilateral nephrectomy. Median length of stay was 3 days. There were no major complications or urine leaks. Two patients were lost to follow-up. The remaining 10 were followed up for a median of 36 months (range, 3-79 months). There have been no recurrences or unplanned readmissions. Mean GFR is 107.7 (±32.8) mL/min per 1.73 m2, with no patient having a GFR below the lower limit of normal for age. ConclusionNephron-sparing resection is a safe and effective approach for children with BWT or contralateral recurrence and should be part of the multimodality therapeutic approach to this disease.

836 DIFFERENTIAL DIAGNOSIS BETWEEN CARCINOMAS AND ADENOMAS OF THE ADRENAL CORTEX IN CHILDREN: A COMPARISION OF 3 HISTOPATHOLOGIC SYSTENS

dren treated at our institution for bilateral Wilms tumor without antecedent diagnostic biopsy. All received vincristine, actinomycin D, and doxorubicin for a minimum of 6 weeks prior to surgery. RESULTS: Age at clinical diagnosis ranged from 8 to 63 months. All 5 children had a palpable abdominal mass. Ultrasound failed to detect bilateral disease in 3. All diagnoses were made with cross-sectional imaging. Studies to rule out neuroblastoma were obtained in 4. Time from diagnosis to chemotherapy ranged from 2 to 8 days. After 6 weeks of chemotherapy, the average decrease in size of the largest tumor and the largest contralateral tumor was 41% (median 49%) and 47% (median 34%), respectively. In 2 cases where additional chemotherapy was given to further reduce tumor size preoperatively, the interval decrease in size of the largest tumor was 14-16% with no change in contralateral tumors; in one, all other ipsilateral tumors increased. Radical nephrectomy was required in 3 children on one side only; one whose multifocal tumors increased in size after additional chemotherapy, one who had the only mass to increase in size after initial chemotherapy (11.0 to 11.2 cm), and one who underwent conversion to radical nephrectomy due to an inability to spare the renal vein and collecting system. Renal function was preserved in all 3. In 2 kidneys, the largest tumors were reduced from 16.0 to 8.2 cm and from 6.7 to 3.0 cm; partial nephrectomies were achieved. Among all other partial nephrectomies, the largest tumor was 2.8 cm at diagnosis. Pathology confirmed Wilms tumor in all children. Only 2 who had pulmonary metastases at diagnosis had individual kidney staging greater than Stage I. After an average 5 months postoperative followup, monitoring of pulmonary lesions is ongoing in 3 children and 2 have no evidence of disease. CONCLUSIONS: In our series, biopsy-free management of bilateral Wilms tumors did not lead to misdiagnosis. While bilateral partial nephrectomies were achieved, neoadjuvant chemotherapy did not preclude radical nephrectomy in 3 children.