Search

Nephroblastoma (Wilms' tumor) is an embryonic tumor, an adenomyosarcoma that is casuistically rarely encountered in adults. It most commonly develops in children aged 1 to 5 years. This type of malignancy does not usually spread to the myocardium. The paper presents a clinical case of Wilms' tumor in an adult female patient with a solitary metastasis in the heart.

There may be a number of tumors made up by small round blue cells in the kidneys of children. One of them is primitive neuroectodermal tumor (PNET). The differences in therapeutic approaches determine the need to establish an accurate diagnosis. The differential diagnosis of PNET and the blastemal component of Wilms tumor can be difficult due to the similar histological pattern. There is a need for a close analysis of morphological manifestations, by keeping in mind the age of patients, and supplementary studies. A strong CD99 membrane expression and nuclear FLI1 expression in tumor cells are the signs of PNET. Reverse transcriptase-polymerase chain reaction and fluorescence in situ hybridization can determine PNET-specific translocations [t(11;22)(q24;q12), by involving the EWS gene.

The accuracy of magnetic resonance imaging (MRI) in the diagnosis of Wilms' tumor (WT) and in the evaluation of preoperative chemotherapy (PCH) efficiency was investigated and compared with histopathological data of 56 children and infants with proven retroperitoneum neoplasma (WT--49, neuroblastoma--6, congenital mesoblastic nephroma--1). The author described the WT MRI-semiotics in general and in particular for its changes during the preoperative chemotherapy. The formula for calculation of tumor reduction index is suggested. The MRI sensitivity (100%), specificity (77.8%) and accuracy (91.1%) are detected. The high positive correlation level between the MRI and pathologic findings, concerning WT dimensions, pseudocapsule presence and safety, tumor structure secondary alterations and tumor spreading was found. At the same time, the specific MRI criteria for the different histological types of WT were not found. MRI is confirmed to be an accurate tool for diagnostic monitoring of patients with WT and other retroperitoneum neoplasms.

The paper deals with a diagnostic informational and analytical system (DIAS). The system is based on the current concept of a dynamic model of nephro-urological clearance macroregulation under retention factors at the pre-, intra-, and postrenal levels during drug load tests. DIAS includes a package of dynamic renoscintigraphic techniques, as well as original software support. A system for parameters of renal clearance regulation has been developed, which is effective at nephro-urological screening and monitoring at all treatment stages for cancer patients. A two-detector chamber which permits the mounting of a detector at an angle to the patient's body is the optimum diagnostic apparatus for a cancer clinic. The use of functional tests makes it possible to examine the regulatory reserves for each kidney, followed up by the choice of adequate corrective measures to prevent renal failure during treatment. In some cases, DIAS monitoring frequently shows a higher sensitivity to the signs of latent renal failure than does routine clinical and laboratory monitoring. The effective radiation dose taken by a patient during a study by the DIAS technology aimed at reducing radioopaque doses is 100-150 times higher than that at an X-ray study and is an order less than during routine urinary tests.

The treatment of nephroblastomas which accounts for 72% of all malignant neoplasms in children is one of the topical problems of pediatric oncology. To detect the tumor at early stages of a tumorous process is one of the main conditions of successful treatment for nephroblastomas. The histological types of nephroblastoma, its international classifications and present-day treatment policy are given. A role of radiation treatment is shown at pre- and postoperative therapeutical stages. Drugs, their combinations, and the efficiency of polychemotherapy regimens in use are outlined. The importance of comprehensive examination of the patient to determine the extent of malignancy and to choose adequate antitumor treatment regimens is emphasized.

Nephroblastoma or Wilms' tumor occurs most frequently in children. New approaches to diagnosis and treatment of this malignancy introduced for the last 15 years are reviewed. Current approaches are characterized by advances in computer noninvasive diagnostic techniques and more aggressive chemotherapy. The first line treatment is polychemotherapy (1 or 2 courses) followed by surgical intervention and postoperative drug or drug+radiation treatment. As shown by follow-up, 40% of patients with nephroblastoma stage III and IV are now free of recurrences and metastases for at least five years. Special investigations are needed to elucidate these children's quality of life, physical, social and mental fitness. Serious problems still remain in perfection of programmed treatment of children with prognostically unfavourable factors.

4 rare cases are reported of adult Wilms' tumor in females aged 35-65. It had been developing subclinically for a long time and was detected at palpation or at abdominal ultrasonography. In the 35-year-old woman the weight of the removed tumor reached 3.5 kg. Wilms' tumor in the adults seems to run asymptomatically and, consequently, is likely to be diagnosed late.

Total serum lactate dehydrogenase (LDH) activity was studied in 65 children with nephroblastoma at stage II-IV. Total LDH activity was elevated in 87% of cases. A correlation between incidence and level of LDH activity, on the one hand, and stage size of tumor, on the other, was established. The increase in total LDH activity at stages II and III in 75 and 85.7%, respectively, was found to match those in LDH concentration 1.2-4-fold and 1.3-7.3-fold, enhanced 1.4-8.4 times. Successful radiation therapy and/or surgery was followed by LDH level coming back to normal. However, failed treatment and further progression of tumor involved persistent rise in the enzyme activity.

A total of 450 children with nephroblastoma were treated in the children's oncological department of the All-Union Cancer Research Centre, the USSR Academy of Medical Sciences, between 1976 and 1986. Tumour relapses were diagnosed during various terms of postsurgery in 131 (29.1 per cent) of them: true relapses in 58 (44.1); retroperitoneal lymph nodal metastases in 56 (42.7 per cent) and the both patterns in 17 (13.2 per cent) patients. The majority of the children were older than 3 years. The initial and the most common manifestations of nephroblastoma relapses were the following symptoms: weakness and diminished appetite (93.1 per cent) pale skin (78.6 per cent), abdominal pains (77 per cent), enlarged abdomen (73 per cent), a palpable tumour (82.4 per cent), neurological symptomatology: defecation and urination disorders (12.9 per cent), pareses and paralyses of lower extremities (6.8 per cent). Timely usage of diagnostic complex measures (palpation under the control of myorelaxants, ultrasonic and computed tomography, angiography) enables one to diagnose nephroblastoma relapses. Such histological patterns of nephroblastoma as nondifferentiated blastema, sarcomatoid and rhabdoid tumours were considered as prognostically unfavourable ones. More relapses were diagnosed in children over 4 years. Some cases of nephroblastoma relapses are also caused by the operative technique (lumbar incision in nephrectomy) and extension of the tumour (into the adjacent organs and tissues--Stage II disease). Pre- of intraoperative ruptures of tumour capsules is a principal factor contributing to relapses. Radiation and chemotherapy are found to be mandatory for the prevention of the ruptures.

Wilms' tumor occurs extremely rarely in adults. There is no consensus in the literature on the problems of clinical manifestations, diagnosis and treatment of the disease. Ten adult patients (aged 16-29) with Wilms' tumor formed the study group. They made up 0.9 per cent of the total number of kidney tumor patients. The peculiarities of the clinical course that distinguish adult nephroblastoma from renal cancer and Wilms' tumor of the infancy were analysed. The latent period appeared to be long. Problems of diagnosis are discussed. Angiography proved to be of the highest diagnostic value. Complex treatment including transperitoneal nephrectomy, radiation and chemotherapy was carried out in 7 cases, palliative chemotherapy and radiation treatment--in 3. Unlike pediatric nephroblastoma, Wilms' tumor in adults was resistant to radiation. Treatment results still remained unsatisfactory: 6 patients died 7-19 months after the beginning of treatment.

An evaluation of 388 cases of Wilms tumor within 13 years established a high proportion of advanced cases among children: stage II - 30.6; III - 35.4; IV - 27.6 and V (bilateral) - 6.4%. Main homeostatic indices remained unchanged until stages III-IV. Primary tumor and metastases can be detected by a complex of clinical, X-ray and radioisotope methods the effectiveness of which is determined by degree of tumor extension. Dissemination of tumor at different sites were detected by primary examination in 40.5% and at later stages in 15% of patients. Most metastases (96%) were detected within the first 12 months of therapy. They were significantly more frequent at stage III and their frequency was in correlation with the patient's age at the time of tumor detection. Out of 388 cases, 112 (28.9%) survived for more than 3 years, stage II - 57.1; stage III - 25.4 and stage IV - 4.6% included. 1.5 - 2 year-long courses of pre- and postoperative polychemotherapy proved to be effective, whereas in cases of stage III tumor they should be supplemented with irradiation of primary tumor, its bed, regional lymph collectors and metastases. These measures ensured a 3-year survival in 69.5% of stage II patients and in 32.3% of stage III patients.

The results of preoperative polychemotherapy of nephroblastoma in 14 children are presented. Ultrasonic tomography, computed tomography and angiography were performed in all the patients before and after medication. The findings on the efficacy of polychemotherapy were assessed on the basis of surgical evidence and, in particular, resected material examination. A high diagnostic value of all the methods was demonstrated and criteria of the effectiveness of preoperative polychemotherapy as evaluated by application of ultrasonic and computed tomography and angiography were worked out. Optimal terms of carrying out diagnostic procedures in patients with nephroblastoma during preoperative treatment are suggested.

Thirty-two 4 month--5 year old children suffering liver tumors, renal cysts, Wilms' tumor and dermoid cysts of the ovary underwent ultrasonic examination. The data obtained were compared to those of histologic examination of autopsy and resected material.

Three cases of the "cellular" variant of mesoblastic nephroma are reported. A feature of one of them was prolonged (7.5 months) spontaneous development of the tumor which presented a peculiar morphologic appearance. Diagnostic differentiation of mesoblastic nephroma from Wilm's tumor and sarcomas is discussed. Results of an electron-microscopic study of one of the tumors are given.

The authors have examined 92 children with renal tumors. The treatment for Wilms tumor should be combined: preoperative irradiation, nephrectomy, postoperative irradiation. Late results were studied in 48 patients. 16 patients (33.3%) are living without the recurrence and metastases for over two years, including 4 over 5 years.