Imaging Patients with Wilms Tumor

Nephroblastoma is a success of paediatric oncologic therapy. How further can we go?: Results of a cyto-histologic correlation study

Nephroblastoma is a success of paediatric oncologic therapy, yet, there are still some cases where favourable response to preoperative chemotherapy is not achieved. Fine needle biopsy has the role of diagnostic confirmation and, idyllically of predicting a response to preoperative chemotherapy. To advance in this aim, we retrieved a total of 14 nephroblastomas, (seven male patients and seven female with a mean age of 44.4 months), diagnosed in our department by fine needle biopsy and submitted afterward to chemotherapy and nephrectomy, in the last 10 years. Correlation between cytologic features, (morphology, cell death, and proliferation (Ki-67 labelling index), and post chemotherapy tumour evaluation was done. Cytologic pattern per se was not predictive of histologic tumour classification (P = 0.6061). We did not find any correlation between the percentage of necrosis and apoptosis (P = 0.682) in cytologic smears and histologic regressive changes but when both these two criteria coexisted in cytologic blastemal component of nephroblastomas, this fact seemed to lead to a favourable response of the tumour to chemotherapy. When evaluation of Ki-67 labelling index was done in the blastematous component present in the smears, divergent results were obtained. The small number of cases prevented any firm conclusions. By summing up, our results support the idea that there are probably two types of blastema in nephroblastoma with different "suicide" potential and chemotherapeutic response. Further studies should be performed to stratify the influence of necrosis, apoptosis, and proliferation in chemosensivity of nephroblastomas.

Imaging of renal tumours in infancy and childhood

There is a large range of benign and malignant renal neoplasms. This article lists the most benign, indeterminate and malignant renal tumours that occur during infancy and childhood. It briefly describes the most important entities, including their imaging features, and important complications. Differential diagnosis and pitfalls are discussed, and a brief suggestion for a standardised imaging algorithm is proposed. Although modern imaging techniques, including colour Doppler sonography, helical or multidetector CT, and MR have significantly improved imaging potential, the definite diagnosis on tumour entity still is established only by histology.

Factors affecting the risk of contralateral Wilms tumor development: a report from the National Wilms Tumor Study Group

BACKGROUND

Approximately 1% of children with unilateral Wilms tumor develop contralateral disease. The authors assessed the demographic and histologic features associated with metachronous bilateral Wilms tumor (BWT).

METHODS

Characteristics of all children registered on the first four National Wilms Tumor Studies (NWTS) were recorded. The primary endpoint for evaluation was the first appearance of Wilms tumor in the remaining kidney. The cumulative risk of contralateral disease as a function of time since initial presentation was calculated as 1 minus the Kaplan-Meier estimate of remaining free of contralateral disease. A matched case control study was conducted to determine whether the presence and type of nephrogenic rests (NRs) were associated with metachronous BWT.

RESULTS

Fifty-eight of 4669 registered children developed metachronous BWT; 38 of 2445 females (expected, 30.2) versus 20 of 2224 males (expected, 27.8) (P = 0.04) developed BWT. The cumulative incidence of contralateral disease 6 years after initial diagnosis decreased from greater than 3% in the first NWTS to approximately 1.5% in the three subsequent studies (P = 0.08). Patients with NRs had a significantly increased risk of metachronous BWT. This was particularly true for young children (20 of 206 age < 12 months compared with 0 of 304 age > 12 months). Data from the matched case control study confirmed the increased relative risk associated with young age and the presence of NRs.

CONCLUSIONS

Children younger than 12 months diagnosed with Wilms tumor who also have NRs, in particular perilobar NRs, have a markedly increased risk of developing contralateral disease and require frequent and regular surveillance for several years. Surveillance is also recommended for those with NRs who are diagnosed after the age of 12 months.

[Unusual presentation of nephroblastomatosis]

BACKGROUND

Nephrogenic rests generally constitute precursor lesions of Wilms' tumor. We report a case of right nephroblastomatosis with dysmorphic features.

CASE REPORT

An enlargement of the right kidney was incidentally discovered in a 1-year-old girl with dysmorphic features but normal psychomotor development. Combined ultrasonography and computerized tomography (CT) scan showed right cortical nephroblastomatosis. Chemotherapy using actinomycin D and vincristin was successful; however, an hyperechogenic nodule was subsequently found, necessitating a right nephrectomy.

CONCLUSION

The relationship between nephroblastomatosis and Wilms' tumor is discussed. This case report reminds us of the importance of a long-term follow-up including echography and CT scan in cases of nephroblastomatosis.