Clear cell sarcoma of the kidney: a review of 351 cases from the National Wilms Tumor Study Group Pathology Center.

We reviewed 351 cases of clear cell sarcoma of the kidney (CCSK), including 182 cases entered on National Wilms Tumor Study Group (NWTSG) trials 1-4 for which clinical follow-up information was available. Tumors were restaged using NWTS 5 criteria. Mean age at diagnosis in the NWTS group was 36 months with a range of 2 months to 14 years. The male to female ratio was 2:1. Typical gross features included large size (mean diameter 11.3 cm), a mucoid texture, foci of necrosis, and prominent cyst formation. Nine major histologic patterns were identified (classic, myxoid, sclerosing, cellular, epithelioid, palisading, spindle, storiform, and anaplastic); virtually all tumors contained multiple patterns that blended with one another. Immunohistochemical stains were performed on 45 cases; only vimentin was consistently immunoreactive. Consistently negative results with other antibodies helped exclude other tumors in the differential diagnosis; all CCSKs were cytokeratin-negative, including epithelioid tumors that mimicked Wilms tumor, and MIC2-negative, including cellular tumors that mimicked primitive neuroectodermal tumor. The p53 gene product was rarely overexpressed in non-anaplastic CCSKs, but strikingly overexpressed in two of three anaplastic CCSKs. Overall survival was 69%. Multivariate analysis revealed four independent prognostic factors for survival: treatment with doxorubicin, stage, age at diagnosis, and tumor necrosis. Of note, stage 1 patients had a remarkable 98% survival rate. No other histologic or clinical variable independently correlated with survival.

Histological analysis of aggressiveness and responsiveness in Wilms' tumor.

The clinical behavior and outcome for any neoplasm are determined originally by its aggressiveness. As adjuvant therapy becomes increasingly effective for that neoplasm, responsiveness to therapy assumes a larger role in determining outcome. Wilms' tumor (WT) provides instructive examples of the dissociation of aggressiveness from responsiveness. The presence of gigantic nuclei with multipolar mitotic figures (anaplasia) appears to be a marker of resistance to therapy, but not of increased aggressiveness. For this reason, anaplasia in a stage 1 WT and anaplasia confined to discrete foci within the primary tumor have no adverse prognostic significance following surgical resection. The prognostic significance of anaplasia is apparently limited to those patients in whom anaplastic cells remain following attempted surgical resection. WT with predominantly epithelial differentiation usually have a low degree of aggressiveness. In this study, 81.3% of WT with this pattern were stage 1. This feature accounts for the high cure rate associated with this pattern prior to the advent of effective adjuvant therapy. However, epithelial predominant WT that present with advanced stage disease may be quite resistant to therapy, with relapse and death rates higher than for more aggressive WT patterns. In contrast, the diffuse blastemal pattern is associated with marked aggressiveness, but with high survival rates suggesting it is usually responsive to current therapy. These features illustrate the independence of aggressiveness and responsiveness in determining outcome for some patients with cancer. Grading systems must be reevaluated with each significant change in therapy. In order to formulate rational therapy, it is important to determine whether prognostic markers are associated with aggressiveness or responsiveness.

Ruptured abdominal aortic aneurysms--prognostic indicators and complications affecting mortality. A local experience.

Although elective abdominal aortic aneurysm (AAA) repair can be done with a less than 5% mortality rate, ruptured AAAs have a 32-85% mortality rate. The aims of this study were: (i) to identify prognostic factors affecting mortality; (ii) to identify and assess the impact of postoperative complications on mortality; and (iii) to try to identify a subgroup of patients who would not benefit from surgery. The records of 54 patients presenting with ruptured AAAs were reviewed; 49 of these patients were operated on, 43 of them males and 6 females (mean age 67 years). The operative mortality rate was 44%, most patients who died doing so in the intensive care unit. In 14 cases AAA was diagnosed before rupture--6 of these patients died. Factors that had a significant effect on mortality were: (i) associated ischaemic heart disease--83% of these patients died postoperatively; (ii) the degree of shock on admission--66% of patients with a blood pressure on admission of 85 mmHg or less died; and (iii) the number of postoperative complications per patients--those with 2 or more complications had an 83% mortality rate. Factors that did not correlate statistically with mortality were age, time interval to surgery, volume and composition of intra-operative fluid therapy, and length of surgery. The most important correctable error was failure to operate electively. From the factors assessed it was not possible clearly to identify a subgroup of patients in this study who should have been excluded from surgery.

Duplex Doppler investigation of suspected vascular lesions at the carotid bifurcation.

This prospective study was undertaken to evaluate the role of duplex Doppler (DD) scanning in the diagnosis of masses of suspected vascular origin at the carotid bifurcation. We also assessed the different DD signs of carotid body tumors, especially the difference in resistance index (RI) in the external carotid artery on the side of the tumor. Over a 3-year period (1987-1991) all patients (n = 50) with masses of suspected vascular origin at the angle of the mandible underwent DD investigation. The clinical diagnoses included carotid body tumors and carotid bifurcation area aneurysms. Arteriography was also performed in all patients. DD examination diagnosed carotid body tumors in 11 patients, aneurysms in 5, nonvascular lesions in 11, carotid artery kinks in 10, and a prominent carotid bifurcation in 13 patients. In 23 of 50 patients (46%) no pathology (kinks and prominent vessels) was present. DD imaging proved to be 100% accurate in diagnosing these lesions as determined by arteriography. The DD findings in carotid body tumors demonstrated a "wineglass" bifurcation containing a lesion with echoes as well as pronounced and turbulent multidirectional flow ("hypervascular tumor flow"). Low-resistance flow was present in the external carotid artery in 80% of patients, indicating the blood supply of the tumor. Patients with lumps of suspected vascular origin at the carotid bifurcation should be initially investigated by DD examination, which can accurately exclude the diagnosis of carotid body tumors and carotid aneurysms and clearly eliminate arteriography in these patients.

Escherichia coli O157:H7 haemorrhagic colitis. Report of the first South African case.

Escherichia coli O157:H7, although recognised 15 years ago, has only become a significant pathogen since 1982 when two outbreaks of haemorrhagic colitis due to this organism were described in the USA. Since then, numerous such outbreaks have been reported. Recent experience with a patient presenting with E. coli O157:H7-induced haemorrhagic colitis is described. The main features, pathological findings and investigations are described and the principles of management outlined.