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INTERNATIONAL ABSTRACTS
irregular, and the frozen section confirmed perilobar hyperplastic nephroblastomatosis. A right nephrectomy was performed because the tumor could not be separated from the normal renal tissue in the lower pole. The regional nodes were sampled. Histological features of the right kidney were consistent with a cystic, partially differentiated nephroblastoma (CPDN). There was no lymph node involvement. Subcapsular, perilobar hyperplastic nephrogenic rests were found in the residual rim of renal tissue. Left kidney sections confirmed hyperplastic nephroblastomatosis, with immature tubules and blastema. The child received actinomycin and vincristine chemotherapy according to NWTS group protocol for stage I Wilms’ tumor of favorable histology. The area of the nephrogenic rests was less well defined in the postoperative sonogram scan and could not be seen after 6 weeks of chemotherapy. However, a new nodule was seen in the upper pole of the left kidney on a CT scan and sonogram performed 12 weeks after chemotherapy. Excision biopsy showed a nodule comprised of blastemal tissue, compressing the adjacent rim of subcapsular nephrogenic rests characteristic of neoplastic nephroblastomatosis. The authors believe that the cystic neoplasm (CN), CPDN, and Wilms’ tumor are histologically related entities analogous to ganglioneuroma, ganglioneuroblastoma, and neuroblastoma. Management of nephroblastomatosis is uncertain and was made more difficult because of the presence of well-defined areas of hyperplastic nephroblastomatosis in the contralateral kidney. Therefore, a short course of chemotherapy was given after nephrectomy. The authors address the difficulties in the management of patients with CPDN associated with nephroblastomatosis and refer to limited literature available on this subject. Therefore, they believe that multicenter retrospective and prospective studies are necessary to better define the management of patients with cystic renal neoplasms.-II. Surana
Small Bowel Obstruction After Nephrectomy for Wilms’ Tumor: A Report of the National Wilms’ Tumor Study-3. M.L. R&hey, P.P. Kelalis, R. Etzimi, et al. Ann Surg 218:654-659, (Nwem-
ber), 1993. Patients enrolled in the Third National Wilms’ Tumor Studywho underwent tumor resection were reviewed for the incidence and predisposing factors to small bowel obstruction (SBO) in the postoperative period. The children were assigned to a calculated stage, based on the extent of local disease. C-stage I patients (n = 796) were those with complete resection, C-stage II patients (n = 499) had microscopic evidence of capsular penetration, local tumor spillage, complete excision of local tumor extension, or extrarenal vascular extension, and C-stage III patients (n = 594) had residual disease, diffuse tumor spill, peritoneal implants, or positive regional lymph nodes. All stage IV patients were reassigned to a calculated stage, based on local findings. The median age at diagnosis was 3 years, and the median duration of follow-up was 5.1 years. The majority of patients were explored via transverse abdominal transperitoneal incisions. Postoperative complications were encountered in 19.8% of 1,910 patients. One hundred thirtyone patients (6.9%) had SBO, which occurred between 3 and 1,993 days postoperatively. Fifty-four percent of 530 occurred during the first 100 days after surgery. The etiology of SBO was adhesions in 104, intussusception in 17, and internal hernia in 2. Sixteen of 17 cases of intussusception were noted within the first 3 weeks of surgery. Intussusceptions were Ileoileal (13) ileocolic (3), and jejunal (1). There was no difference in the incidence of SBO between patients with bowel resection and those with en bloc resection of other visceral organs. The bowel anastomosis was not the site of obstruction in any patient. Log-rank tests identified potentially important parameters to SBO: intravascular tumor extension, resection of other organs, preoperative tumor rupture,
residual disease, C-stage III, and possibly tumor spill. The incidence of SBO for stage II, favorable histology (FH), is higher in patients receiving postoperative abdominal irradiation, but the difference is not statistically significant. Similarly, the incidence of SBO was higher in patients with stage III, FH, who received 2,000 cGy, but the difference is not significantly different. The actuarial estimated survival at 2 and 5 years for patients with and without SBO is similar. This review showed that the most significant factors in explaining the development of postoperative SBO after nephrectomy for Wilms’ tumor were higher local tumor stage, extrarenal intravascular involvement, and en bloc resection of other organs at the time of nephrectomy. Each of these factors suggests that a more extensive operative procedure was performed to extirpate the tumor. The length of operative procedure was not available to confirm the hypothesis.--Edward G. Ford Clinical Study of 537 Neuroblastomr Patients Diagnosed Before 1 Year of Age. Part 2: Primary Tumor, Metastasis, Histology and Laboratory Data. T. Shikata, T. Matsumura, Y: Matsuda, et al. J Jpn Sot Pediatr Surg 29:1109-l 118, (October),
1993. To recommend a therapeutic regimen for neuroblastoma patients diagnosed before 1 year of age, the authors conducted a survey, by questionnaire, throughout Japan. Five hundred thirtyseven patients were registered. The mean weights of primary masses in stage I or II were 44.8 g in 204 cases detected by mass screening (MS) and 87.9 g in 37 cases not detected by mass screening (non-MS). Local extension was observed in 41% of 350 MS cases and in 57% of 143 non-MS cases. Metastases were observed in 52% of 350 MS cases and in 73% of 175 non-MS cases. Of 511 cases, the histological diagnosis was ganglioneuroblastoma in 24% and neuroblastoma in 76%. Most of the non-MS cases with round cell type were in stage III, IV-A or IV-B. The urinary vanillylmandelic acid was less than 25 per milligram creatinine in 18% of 336 MS cases and in 22% of 82 non-MS cases, and the homovanillic acid was less than 35 in 26% of 332 MS cases and in 20% of 79 non-MS cases. VMA and HVA were more sensitive markers for detecting these cases than was serum neuron-specific enolase (NSE). Most non-MS cases with higher levels of serum NSE, ferritin, or LDH were in stage III, IV-A, IV-B, or IV-S. Local extension and metastases were observed in most of the cases diagnosed before 1 year of age, although their primary masses were small. Most MS cases had smaller primary masses, less local extension, and less metastasis than the non-MS cases.-Takeshi Miyano lmmunohistochemical Analysis of N-myc Protein and ns p21 Expression in Human Neuroblastoma: Correlation With Prognosis. Takahatu Oue, et al. J Jpn Sot Pediatr Surg 29~977-986,
(August), 1993. N-myc protein and ras p21 expression were analyzed in 76 primary neuroblastomas by immunohistochemical techniques using formalin-fixed paraffin sections. N-myc protein expression was detected in 17 of 76 cases (22.4%). The 5-year survival rate (SYSR) of the patients with N-myc protein expression was significantly lower (17.3%) than that of patients without it (69.8%) (P < .OOl). ras p21 expression was detected in 35 of 76 cases (46.1%). The 5YSR of patients with ras p21 expression was significantly higher (84.2%) than that of patients without it (40.7%) (P < 0.01). Both N-myc protein and ms p21 expression correlated with patients’ age, clinical staging, mass screening, and DNA ploidy, but not with tumor histology. The patients with N-myc-positive expression had a poor prognosis. In contrast, N-myc-negative expression did not necessarily suggest a good prognosis. In these cases, ras-p21 expression suggested a good prognosis. It is concluded that the immuno-