Renal neoplasms of the newborn

Diagnosis of fetal renal anomalies

Urinary tract abnormalities are fairly common in the perinatal period. Ultrasonography is an effective diagnostic tool for identifying fetal urinary tract anomalies and can be helpful in establishing prognosis and guiding treatment decisions. The sonographer is encouraged to characterize and localize the fetal urinary tract abnormality when identified. In doing so, the correct diagnosis can be selected from the differential possibilities, providing vital clinical information needed to develop a care plan for both the pregnant woman and her fetus.

Wilms' tumor in the neonate: a report from the National Wilms' Tumor Study

Renal neoplasms in the neonate are quite uncommon. Twenty-seven of the 3,340 patients (0.8%) registered on the National Wilms' Tumor Studies from 1969 through April 1984, were 30 days old or less. Of these 27 patients, 18 had mesoblastic nephroma, 1 had a malignant rhabdoid tumor of the kidney, and 4 others had nonneoplastic lesions. The remaining four infants were reviewed in detail. All had favorable histology Wilms' tumors; none had distant metastasis at diagnosis. Treatment ranged from surgery alone to excision plus three-drug therapy for 15 months. All fared well. The patient with Stage I rhabdoid tumor died at eight weeks of age in spite of aggressive four-drug therapy. This review supports the view that Wilms' tumor in the neonate is extremely rare.

Congenital mesoblastic nephroma: relationship to other renal tumors of infancy

Although nephroblastomas (Wilms tumor) do occur in the newborn most of the solid renal tumors in this age group constitute a distinctly different pathologic entity, congenital mesoblastic nephroma. While a more cellular histologic variant of congenital mesoblastic nephroma has been recognized recently, which occasionally may follow a malignant course, the tumor with conventional histology has never been reported to metastasize and follows a benign course when treated by adequate local excision alone. We report our 50-year experience with 11 cases of this tumor (9 cases with conventional histology and 2 with cellular variant histology). Typically, the tumor presented in the newborn as a large asymptomatic mass. Local invasion was never seen and the tumors were resected without difficulty. Grossly, the tumors usually resembled a uterine "fibroid" and, unlike nephroblastomas, rarely exhibited hemorrhage or necrosis. Microscopically, the conventional histologic congenital mesoblastic nephroma was composed of sheets of spindle-shaped cells. The cellular variant of congenital mesoblastic nephroma exhibited increased cellularity and a higher mitotic index. The relationship of congenital mesoblastic nephromas to other neonatal renal tumors is discussed and a unifying schema of neoplasia in infantile renal tumors is proposed.

Wilms' tumor--model of a curable pediatric malignant solid tumor

Wilms' tumor is the model of the treatment of a pediatric solid tumor. Initially it appeared that multi-modality therapy, consisting of transabodominal nephrectomy, post-operative radiation therapy to the tumor bed and adjuvant, single agent chemotherapy provided the highest likelihood of disease-free survival. The identification of important prognostic factors, such as histology, tumor weight, lymph node involvement and age at diagnosis has led to a re-examination of the treatment of Wilms' tumor. Future therapeutic developments will include the administration of less therapy to some well defined groups of patients, and the exploration of new programs for patients who have been demonstrated to have a poor prognosis using currently accepted treatment techniques.

Cultural characteristics of mesoblastic nephromas

Seven infants and children with renal tumors underwent nephrectomy and the tumors were cultured to investigate the behavior of their cells. In four children over 1 year of age with histologically typical nephroblastoma in the tumor cells were bizarre and disorderly. In one patient 3 months of age where the histology suggested malignancy the tumor culture showed an orderly growth pattern of spindle cells akin to normal kidney and the patient has had no recurrence for 18 months. In one infant seven months of age the histology was consistent with malignancy and this was confirmed on culture showing bizarre cells similar to those of nephroblastoma. The third infant under 1 year of age had a teratoma on histology and an unusual growth pattern on culture characterised by polyhedral cells with long processes and much overlapping. It is suggested that in infants with kidney tumors, tissue culture be used to help in assessing the malignant potential of the tumor and deciding on adjuvant therapy.

Renal tumours in children

A ten-year series of renal tumours in children up to 14 years of age was collected from the files of the Finnish Cancer Register. After histological evaluation of the material, 74 cases were accepted as primary renal tumours. Fifty-eight of these were typical Wilms' tumours, three rhabdomyosarcomas, six foetal hamartomas and seven unclassified malignant tumours. Wilms' tumours were classified into three types on the basis of the histological differentiation. The total five year survival in the Wilms group was 50 per cent with no difference between patients over and under the age of one year. Of the subtypes of Wilms' tumours the sarcomatous type showed worse prognosis than average; only three out of 16 patients were alive after a five-year follow-up time. None of the patients with foetal hamartoma died of tumour, although two fatalities, connected with the surgery, were recorded. The value of histological classification of Wilms' tumours and the importance of the recognition of the foetal hamartoma is emphasized.