A review of all cases of nephroblastoma admitted to the University Hospital over a 10 year period reveals that its incidence relative to the other childhood tumours and epidemiological features are similar to other centres. The majority of patients presented with either stage III or IV disease. During the period 1968·1972 the number of defaulters was high and survival was poor. Following the introduction of treatment protocol, default rate has fallen and 5 of 7 patients have survived more than 2 years. Earlier referral and education of the parents should help improve the outcome for children with Wilms' tumour in Malaysia.
Wilms' tumour (nephroblastoma) has been associated with chromosomal abnormalities at the 11p13, 11p15 and 16q regions. A study into the possibility of mutations occurring within p53, the ubiquitous adult tumour suppressor gene, in Wilms' tumour was carried out. Thirty-eight cases were studied. Of these 36 were categorised into the favourable histology group and two into the unfavourable histology group based on the National Wilms' Tumour Study criteria. Archival formalin-fixed, paraffin-embedded tissue sections from each case were stained with a polyclonal (AB565:Chemicon) and a monoclonal (DO7:Dako) antibody raised against p53 protein using a peroxidase-labelled streptavidin biotin kit (Dako). 'Cure' (disease-free survival of 60 months or longer) was documented in 39% of cases with favourable histology tumours. Eleven percent in this group succumbed to the disease. Both cases with unfavourable histology died. Four out of 36 (11%) tumours with favourable histology demonstrated weak to moderate staining with both AB565 and DO7 in more than 75% of tumour cells. In contrast, p53 protein expression in unfavourable histology tumours was significantly increased compared with the favourable histology group (P = 0.021) with both cases demonstrating immunopositivity in > 75% of tumour cells when stained with AB565 and DO7. The intensity of staining ranged from moderate to strong in both cases. It appears from this preliminary study that the immunohistochemical expression of p53 protein in Wilms' tumour, presumably a result of mutation in the p53 tumour suppressor gene, correlates with histological classification, histological categorisation being one of the useful features in the prognostic assessment of Wilms' tumours.
We report a six-year-old Malay girl who presented with a right retroperitoneal tumour that measured 7.5 cm in diameter. A wide excision of the lesion was performed. The tumour was separated from a normal-appearing right kidney by a capsule. Microscopically, this well-encapsulated tumour was composed of classical triphasic components: epithelial, mesenchymal and blastemal areas. The immunohistochemical study showed WT1 expression in the blastemal area. Thus, a diagnosis of Wilms' tumour with favourable histology was made. The patient was well for 12 months. Extrarenal Wilms' tumour is uncommon, with the majority of cases occurring in the retroperitoneal and inguinal areas. Wilms' tumour that is not arising from the intrarenal area but shares a common capsule with the ipsilateral kidney, is even rarer. Indeed, our case would be more appropriately classified as juxtarenal/pararenal Wilms' tumour. Despite its rarity, an extrarenal or even juxtarenal/pararenal Wilms' tumour should be included in the differential diagnosis of retroperitoneal tumour.
Formerly thought to have a constant incidence rate throughout the world, Wilms' tumour (nephroblastoma) has been shown to be less common among Asian children. A retrospective demographic and morphological study of Wilms' tumour histologically diagnosed over a 22-year period at the Department of Pathology, University Hospital, Kuala Lumpur was conducted to assess for inherent demographic and morphological differences between tumours in Malaysian children and those of Western populations. Thirty-seven cases of histologically proven Wilms' tumour qualified for inclusion in this study. 19 patients were Chinese, 13 Malay, 4 Indian and 1 Anglo-asian. 21 were male and 16 were female (M:F ratio = 1.3:1). Their ages ranged from 1 month to 4 years. 70.3% of the patients were below 2 years of age. 36 cases had unilateral and 1 bilateral tumours. Of unilateral tumours, 19 involved the left kidney and 17 the right. Histological assessment, based on criteria of the National Wilms' Tumor Study Group, revealed 20 (52.6%) tumours with a mixed pattern while 8 (21.1%) showed epithelial, 7 (18.4%) blastemal and 3 (7.8%) stromal-predominant patterns. Anaplasia was observed in only 2 tumours (5.3%). There was no obvious difference in age range and sex distribution, laterality of tumours and incidence of anaplasia between this and Western studies. No ethnic predilection was observed. A notably larger percentage of cases were below 2 years of age. Also, a larger proportion of epithelial-predominant and a lower proportion of blastemal-predominant tumours was observed compared with patterns reported from Western populations.
This study explores immunohistochemical characteristics that may be of diagnostic value in differentiating clear cell sarcoma of the kidney (CCSK) from Wilms' tumor (WT) and may provide some insight into the histogenesis of CCSK. Formalin-fixed, paraffin-embedded sections of 8 CCSK and 9 WT were stained, using the standard avidin-biotin peroxidase complex method, for vimentin (VIM), Factor-8 related antigen (F8A), epithelial membrane antigen (EMA), desmin (DES), S-100 protein and Mac 387. CCSK cells consistently exhibited moderate to strong diffuse cytoplasmic positivity for VIM and were negative for F8A, EMA, DES, S-100 and Mac 387. In contrast, only patchy groups of stromal cells and primitive glomeruloid structures in WT exhibited VIM-positivity. Blastemal cells were VIM-negative. Stromal cells with rhabdomyomatous differentiation exhibited cytoplasmic positivity for DES. Epithelial cells of maturing tubular structures showed EMA-positivity whereas immature tubular structures were EMA-negative. Neither blastemal, stromal nor epithelial elements in WT were positive for F8A, S-100 or Mac 387. Podocytes and mesangial cells of glomeruli in 3 mid-trimester human abortuses (controls) exhibited moderate to strong VIM-positivity. The importance of differentiating CCSK from WT has been repeatedly emphasized because of its poorer prognosis and the necessity of adding Adriamycin to the chemotherapeutic regime. The consistent VIM-positivity of CCSK cells can be a useful feature in differentiating it from "blastemal-predominant" WT, with which it is often confused. Although vimentin expression by CCSK cells is consistent with a mesenchymal character, the possibility of a histogenetic link with glomerular podocytes or mesangial cells should also be considered.
Eight histologically-confirmed cases of clear cell sarcoma of the kidney (CCSK) were studied for possible mutations in the p53 tumor suppressor gene by the immunohistochemical demonstration of mutant p53 proteins using a monoclonal (DO7: Dako) and a polyclonal (AB565: Chemicon) antibody to p53 protein. All cases exhibited p53 protein nuclear immunopositivity, although in varying numbers of tumor cells and with different staining intensities. p53 protein (DO7 or AB565) was expressed in < 25% of the tumor cells in four (50%) of the cases, including the one case with a known long term survival of 13 years from the time of diagnosis. The other tumors showed p53 protein immunopositivity in > 25% of the tumor cells when stained with either DO7 or AB565 or both. The intensity of staining, graded on visual impression into weak, moderate or strong, did not correlate well with the ratio of positive staining tumor cells. While this study is unable to clarify the relative prevalence and importance of p53 mutational events in the pathogenesis of this aggressive renal tumor of childhood, it is reasonably suggestive that alterations in the p53 tumor suppressor gene do occur in CCSK.
Eight cases of clear cell sarcoma of kidney were seen in the Department of Pathology, University Hospital, Kuala Lumpur, Malaysia over the 16-year period from 1973 to 1989. Five of the patients were males. Six patients were Malay, one Chinese and one Indian. The patients' ages ranged from 8 months to 3 years. Clear cell sarcoma was the original diagnosis in two patients while six were diagnosed as blastemal-predominant Wilms' tumours at presentation. Metastases developed in five patients. Metastatic sites included the thoracic vertebra, skull, orbit, humerus, radius, ulna, shoulder, lung and liver. The prolonged survival, of 9 years and 9 months, seen in one patient despite omission of Adriamycin (doxorubicin) from the chemotherapeutic protocol is highlighted. We also emphasise the histological factors which are of help in differentiating clear cell sarcoma from Wilms' tumour.
We report the clinical features and in vitro chemosensitivity assay findings of a 13-year-old girl who developed secondary B-cell acute lymphoblastic leukemia (ALL) 7 years after a diagnosis of Wilms' tumor. The patient was treated using the Berlin - Frankfurt - Muenster (BFM) ALL chemotherapy protocol with poor response to initial therapy before succumbing to sepsis. An in vitro chemosensitivity assay on her peripheral blood lymphoblasts was performed while she was undergoing induction therapy and showed a high level of resistance to drugs commonly used for ALL therapy, e.g. steroids, anthracyclines, vincristine and L-asparaginase. The mechanism of chemoresistance was not elicited, but was probably not related to P-glycoprotein (P-gp) over-expression. We believe that the in vitro chemosensitivity assay is a good indicator of cellular response to chemotherapy and may provide reliable information for the basis of the selection of drugs to be used for the treatment of similarly rare patients rather than relying on "standard" protocols.
Introduction: Denys-Drash Syndrome (DDS) consists of a triad of pseudohermaphroditism, Wilms'tumor and nephropathy. This condition may manifest as a complete triad or in an incomplete form; with either one or a combination of the above features. The characteristic glomerular abnormality in DDS is diffuse mesangial sclerosis (DMS).Case report: We report two cases of DDS with focal membranoproliferative glomerulonephritis (MPGN). Both of our cases were males with ambiguous genitalia. They had a similar heterozygous germline mutation in exon 9 of WT1, c.1180C>T, p.R394W; a known mutation hotspot for DDS. Case 1 had nephropathy at the age of 4 years and Case 2 at 2.5 years with different rates of progression to end-stage renal failure. Conclusion: Our findings, in combination with other reports, illustrate the clinicopathological heterogeneity of DDS. There are no universal recommendations for optimal management of patients with DDS due to the inability to accurately predict affected individuals' progress.
Renal cancer is rare and its incidence is 1.9 per 100,000 in the Malaysian population, which consists of three major ethnic groups (Malay, Chinese and Indians). A retrospective study was her conducted to identify clinical characteristics and ethnic background influences on presentation. The study included all renal cancer patients from a single medical institution over ten years, with a total of 75 cases. Seventy-three patients underwent surgery while 2 received only radiotherapy or chemotherapy. The male to female ratio was 2.75:1. Incidence was equal among the Malay (49.3%) and Chinese ethnic groups (45.3%). Mean age of patients were 57.1 (18-93) years old. There were 26 (37.4%) patients with Stage I disease, 14 (18.7%) at Stage II, 23 (30.7%) at Stage III and 12 (16%) at Stage IV. The Chinese race presented at mean older age (p= 0.02) and later stage of disease (p= 0.046). Patients above 40 years old had more advanced stage disease (p= 0.023). Tumour histology were clear cell (72%), urothelial cell (13.3%), sarcomatoid cell and nephroblastoma each contributed 2.7%. The mean tumour size was 8.1 (2-20) cm. There was substantial agreement between the pre and post operative staging (kappa 0.691). In conclusion we observed significant influences of age and race in the clinical presentation of renal cancer in our institution based population. There was larger male to female ratio and mean tumour size as compared to previous epidemiology studies.