Role of immunocytochemistry, electron microscopy, and DNA analysis in fine-needle aspiration biopsy diagnosis of Wilms' tumor

Clear cell sarcoma of the kidney in a 62-year-old patient presenting with generalized pruritus

Background

Clear cell sarcoma of the kidney (CCSK) is the second most common renal tumor in children following Wilms’ tumor. CCSK is extremely rare in adults, with only 25 adult cases reported in the medical literature.

Case presentation

We reported a 62-year-old man with a right renal mass presenting only with generalized pruritus who underwent radical right nephrectomy. With immunostaining, tumor cells were positive for expressed vimentin, neural cell adhesion molecule (NCAM, CD56), and Ki-67 and focally positive for p53, CD10 and Bcl-2. The histopathological diagnosis was CCSK. Two weeks after the operation, the generalized pruritus ended. One month after the operation, the patient started treatment with a regimen combining doxorubicin, vincristine, cyclophosphamide, and etoposide. At the 20-month follow-up visit, there was no evidence of local recurrence or metastases.

Conclusions

In a patient presenting with generalized pruritus, further evaluation for an underlying malignancy should be considered. It is difficult to distinguish CCSK from undifferentiated renal neoplasms. Immunohistochemistry could help to make exact histopathological diagnoses. The BCL-6 corepressor (BCOR) gene could play a significant role in CCSK tumorigenesis and be a good marker for CCSK diagnosis. Surgery with combination chemotherapy and radiation therapy could be used to treat CCSK in older patients.

Induced Pluripotent Stem Cells Reduce Progression of Experimental Chronic Kidney Disease but Develop Wilms' Tumors

The therapeutic effect of induced pluripotent stem cells (iPSs) on the progression of chronic kidney disease (CKD) has not yet been demonstrated. In this study, we sought to assess whether treatment with iPSs retards progression of CKD when compared with bone marrow mesenchymal stem cells (BMSCs). Untreated 5/6 nephrectomized rats were compared with CKD animals receiving BMSCs or iPSs. Renal function, histology, immunohistochemistry, and gene expression were studied. Implanted iPSs were tracked by the SRY gene expression analysis. Both treatments minimized elevation in serum creatinine, significantly improved clearance, and slowed down progression of disease. The proteinuria was reduced only in the iPS group. Both treatments reduced glomerulosclerosis, iPSs decreased macrophage infiltration, and TGF-β was reduced in kidneys from the BMSC group. Both types of treatments increased VEGF gene expression, TGF-β was upregulated only in the iPS group, and IL-10 had low expression in both groups. The SRY gene was found in 5/8 rats treated with iPSs. These 5 animals presented tumors with histology and cells highly staining positive for PCNA and Wilms' tumor protein antibody characteristics of Wilms' tumor. These results suggest that iPSs may be efficient to retard progression of CKD but carry the risk of Wilms' tumor development.

Adult wilms' tumor metastatic to the lung: endobronchial ultrasound-guided fine needle aspiration biopsy

Adult Wilms' tumor (WT) is a rare entity with less than 300 cases reported to date in the medical literature. Histologic and cytologic features of adult WT of the kidney are similar to findings in pediatric WT. While the lungs are noted to be the most frequent site of metastatic disease in the pediatric population, the incidence of lung metastases remains unknown for adult WT. A search revealed 38 cases of adult WT with lung metastases published to date in the English literature. Amongst these cases only two have utilized cytology of the lung lesions as a means to arrive at a final diagnosis. We report a case of adult WT metastatic to the lung that was initially diagnosed using endobronchial ultrasound-guided fine needle aspiration biopsy. The aim is to compare the current cytologic and immunohistochemical findings with those cases previously published, to outline the cytologic features of adult WT metastatic to the lung, and to emphasize the significance of cytologic diagnosis in the work-up of adult WT.

Clear cell sarcoma of the kidney: a review

Clear cell sarcoma of the kidney (CCSK) is a rare renal tumour that is observed most often in children under 3years of age. Only a few large series of CCSK have been reported and patients with CCSK are often included among patients with other types of childhood renal tumours. The purpose of this paper is to review the published series and case reports of CCSK and to create an up-to-date overview of clinical and histological features, genetics, treatment, and outcome.

Immunohistochemical profiling of Wilms tumor: a tissue microarray study

AIM

Wilms tumor (WT) usually shows a bi-phasic or tri-phasic morphology comprised of blastemal, stromal, and epithelial cells. Other biphasic renal tumors that can mimic WT may pose diagnostic dilemmas especially in preoperative needle biopsy samples. This tissue microarray study was designed to investigate the immunohistochemical features that may prove useful in the accurate diagnosis of WT in small biopsy samples.

METHODS

Eight punches from each paraffin block of 45 cases of WTs were used to construct 5 tissue microarray blocks. Immunohistochemical reactions of blastemal, stromal, and epithelial cells of each core to a panel of 37 antibodies were evaluated.

RESULTS

Blastemal elements expressed CD56 (22, 57%), CD57 (19, 55%), cytokeratin 22 (CK22) (12, 27%), and CK8 (9, 21%). Epithelial cells were stained mostly with CK22 (17, 94%), CK18 (12, 66%), CK8 (14, 70%), CD57 (10, 76%), CD56 (6, 43%), EMA (7, 44%), and CK19 (5, 25%). Stromal cells expressed SMA (21, 50%), actin (18, 48%), desmin (9, 20%), CD34 (7, 24%), CD57 (5, 18%), and CD56 (5, 15%). Only one case was positive for CK5/6, CK13, CK14, and CK20. Calretinin expression was seen in the stromal cells of 3 and placental alkaline phosphatase expression was observed in 1 case. All 3 components were negative for CK1, CK7, myoglobin, Myf-4, MyoD1, HMB45, chromogranin A, synaptophysin, Melan A, beta-HCG, alpha-HCG, alpha-Inhibin, renal cell carcinoma antigen, glycophorin A, PSA, and estrogen and progesterone receptors.

CONCLUSIONS

CD56, CD57, CK22, CK18, CK8, EMA, SMA, and actin are useful markers for an accurate diagnosis of WT in small biopsy samples.

Immunohistochemical Study of Porcine Nephroblastoma

Nephroblastoma, a relatively common renal neoplasm of young swine, represents the animal counterpart of Wilms' tumour of children. Five porcine nephroblastomas were examined histologically, and immunohistochemically with antibodies against vimentin (VIM), cytokeratins (CKs), smooth-muscle actin, Factor VIII, and laminin. Histologically all showed the three components typical of this tumour: mesenchymal blastema, epithelium (tubuli, and glomeruloid bodies) and stroma. The only antibody recognizing mesenchymal cells was VIM. One-third of tubular structures were positive for VIM. All of the tubules were positive for CK19, two-thirds expressed CK AE1/AE3, and only one-third expressed CKs 8-18. Small round tubuli, located in the stromal septa, were positive for CK7 (ureteric branches). Stromal cells expressed both VIM and actin, demonstrating myofibroblastic differentiation. The kidney originates from mesenchymal blastema, which changes to epithelium, losing VIM and acquiring CK expression. In the adult mammalian kidney, CK 19 is expressed only by the parietal epithelium of Bowman's capsule and the distal tubules. Nevertheless, CK19 is also considered a "transient" CK, expressed by different kinds of epithelia during differentiation. CK 19 was also detected in several undifferentiated neoplasms. This finding, together with the co-expression of VIM detected in some tubules, demonstrates the embryonic origin of nephroblastoma.

[Kidney tumors in childhood]

Types of renal tumors arising in children are different from those occurring in adults. Nephroblastoma is the most common (85%) with a clinical outcome which has dramatically improved in the last 30 years. Current classifications are aimed at better adaptation of treatment to each individual case, reducing iatrogenic complications without impairing total cure. Amongst entities which have been recently described or are better known we can find juvenile carcinoma associated with Xp11.2 translocation, renal medullary carcinoma, metanephric tumors, etc. Role of molecular cytogenetics is increasing for classification (and treatment) and this should always be kept in mind when dealing a fresh specimen of childhood renal tumor.

Primary Ewing's sarcoma/primitive neuroectodermal tumor of the kidney: a clinicopathologic and immunohistochemical analysis of 11 cases

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is an extraordinarily rare primary tumor in the kidney and can be mistaken for a variety of other round cell tumors, including blastema-predominant Wilms' tumor (WT). Approximately 90% of ES/PNET have a specific t(11;22), which results in a chimeric EWS-FLI-1 protein. Immunohistochemistry for the carboxy-terminus of FLI-1 is sensitive and highly specific for the diagnosis of ES/PNET. WT-1, the WT-associated tumor suppressor gene, is overexpressed in WT but not in ES/PNET. No study has examined FLI-1 or WT-1 expression in renal ES/PNET. The clinicopathologic features of 11 renal ES/PNET were studied along with immunohistochemistry for cytokeratin, desmin, CD99, FLI-1, and WT-1. WT were also immunostained for CD99 (5 cases), FLI-1 (10 cases), and WT-1 (9 cases). The patients (6 men, 5 women) ranged from 18 to 49 years of age (mean, 34 yr). The mean tumor size was 11.8 +/- 3.8 cm (mean +/- standard deviation). Presenting symptoms included abdominal/flank pain and/or hematuria. Grossly, all tumors showed necrosis and hemorrhage, and 4 had cystic change. Microscopically, all tumors showed vaguely lobular growth, primitive round cells, and variable rosette formation. Epithelial, myogenous, or cartilaginous differentiation was not seen. Immunohistochemical results on the renal ES/PNET were cytokeratin (2/8 focal), desmin (0/9), CD99 (8/8), FLI-1 (5/8), and WT-1 (0/8). In comparison, the WT only rarely expressed CD99 (1/5) and did not express FLI-1 (0/10), but were usually WT-1-positive (7/9). Follow-up on 8 cases (mean, 28 mo; range, 6-64 mo) showed 4 lung and pleural metastases, 1 bone metastasis, liver metastasis, 2 local recurrences, and 5 deaths from disease (median time to death, 16.8 mo). No case had distant metastatic disease at presentation. Adjuvant therapy included chemotherapy (8 cases), radiation (3 cases), and bone marrow transplantation (1 case). Our study affirms a unique proclivity of renal ES/PNET for young adults and that it is a highly aggressive neoplasm, with rapid death in many cases, usually after the development of treatment-resistant lung metastases. These tumors must be distinguished from blastema-predominant WT and other primitive renal tumors that require different therapy. FLI-1 and WT-1 immunohistochemistry may be valuable in this differential diagnosis, given the known immunophenotypic overlap between ES/PNET and blastema-predominant WT with regard to CD99, cytokeratin, and desmin. The accurate distinction between these two entities has clear prognostic and therapeutic implications.

Renal epithelial neoplasms: the diagnostic implications of electron microscopic study in 55 cases

Several unsettled histogenetic, nosologic and diagnostic considerations for renal epithelial tumors may have ultrastructural ramifications. Yet, a comprehensive electron microscopic study of renal epithelial neoplasms, in light of the recent classification, is not available. The ultrastructural findings from fifty-five renal epithelial neoplasms [31 clear cell renal cell carcinomas (RCC), 11 papillary RCC, 5 chromophobe RCC, 3 sarcomatoid RCC and 5 oncocytomas] were correlated with their light microscopic appearance. Clear cell RCC showed long microvilli similar to the brush border of the normal proximal tubules, with abundant cytoplasmic lipid and glycogen. Papillary RCC showed variably sized microvilli, and small amounts of cytoplasmic lipid, but no glycogen. Chromophobe RCC showed many cytoplasmic vesicles and abnormal mitochondria, with rare short and stubby microvilli. Renal oncocytoma showed many mitochondria with a few vesicles in the apical portion of the cytoplasm and rare short and stubby microvilli. The eosinophilic cell variants of clear cell RCC, papillary RCC and chromophobe RCC showed ultrastructural features similar to those of their respective prototypes, except for an increased numbers of mitochondria in the cytoplasm. One sarcomatoid clear cell RCC showed skeletal muscle differentiation. Two types of cytoplasmic inclusions, i.e. hyaline globules and granules similar to those in the Paneth cells (PC-like granules) were identified only in clear cell RCC, which displayed distinctive ultrastructural features. The current EM study demonstrates distinctive ultrastructural features of renal epithelial neoplasms. The findings lend additional support to the current classification of the pertinent tumor types, facilitate the differential diagnoses, and provide insights into the possible histogenesis of renal epithelial neoplasms.

Role of immunocytochemistry and DNA flow cytometry in the fine-needle aspiration diagnosis of malignant small round-cell tumors

In the present study, DNA flow cytometry (FCM) and immunocytochemistry (ICC) with a selected panel of antibodies were performed on 51 cases of malignant tumors which were referred for fine-needle aspiration biopsy (FNAB) to our Department of Cytology for the last 2 yr. Twelve cases were diagnosed as neuroblastoma, 16 as Ewing's sarcoma, 2 as retinoblastoma, 5 as non-Hodgkin's lymphoma (NHL), 5 as rhabdomyosarcoma, 2 as peripheral neuroectodermal tumors (PNETs), and 8 as Wilms' tumor. Eleven of 12 neuroblastomas were diploid by FCM, and 1 was aneuploid, with an S-phase fraction (SPF) of 8.3%. Neuron-specific enolase (NSE) was negative in 3 and positive in 8 cases of neuroblastoma, whereas neuroblastoma marker was positive in 3/11. Sixteen of 17 Ewing's sarcomas were diploid, and 1 showed tetraploid aneuploidy, with an SPF of 10.06%. Eight of 13 Ewing's sarcomas were positive for Mic-2 gene product (Ewing's marker). All 5 NHL were positive for leukocyte-common antigen (LCA). Three of 5 rhabdomyosarcomas were diploid, and 2 cases showed aneuploidy. Rhabdomyosarcoma showed muscle-specific actin positivity in 4 and desmin positivity in 3 cases. All 3 cases of PNET were diploid and positive for the Mic-2 gene product, whereas NSE and vimentin were positive in 2 cases. Both cases of retinoblastoma were diploid. Immunostaining was noncontributory in 1 case, and the other showed positivity for the retinoblastoma gene product, NSE, and chromogranin. Seven of 8 Wilms' tumors were diploid, and 1 showed aneuploid, with an SPF of 11.13%. Seven of 8 Wilms' tumors were positive for cytokeratin (CK), 5 were positive for NSE, 6 were positive for epithelial membrane antigen (EMA), and 5 were positive for vimentin. FNAB diagnosis of malignant round-cell tumors is difficult only by light microscopy. Due to the availability of specific markers for subgrouping tumors, ICC has proved to be more useful these days, while DNA FCM has little diagnostic value, as most of them are diploid. Further ancillary studies, e.g., electron microscopy, image analysis, and other molecular investigations, are required to further categorize these tumors more precisely for better clinical management of these cases.

Fetal rhabdomyomatous nephroblastoma: diagnosis by fine-needle aspiration cytology--a case report

The present report describes the case of a 21-mo-old boy with a fetal rhabdomyomatous nephroblastoma (FRN) diagnosed by fine-needle aspiration cytology (FNAC). The smears contained numerous isolated or clustered, deeply eosinophilic, thin, elongated rhabdomyoblasts with oval nuclei. Some of these cells presented cross-striations. Peculiar clusters of small, deeply eosinophilic, round cells with and without rounded nuclei in a mosaic pattern were interpreted as representing transversally oriented rhabdomyoblasts. Fetal rhabdomyoblasts were by far the predominant type of cell. Histology of the surgical specimen proved 90% of the mass to be constituted of fetal rhadomyomatous tissue. Adequate recognition of FRN is useful for the planning of treatment.

Fine-needle aspiration biopsy diagnosis of small round cell tumors of childhood: A comprehensive approach

Fine-needle aspiration biopsy findings in small round cell malignant tumors of children are briefly reviewed. All of these tumors usually have characteristic cytomorphology which, when recognized, may lead to a definitive diagnosis. However, when these tumors are undifferentiated, morphologic criteria may not be sufficient for arriving at a correct diagnosis. A variety of ancillary studies including electron microscopy, immunohistochemistry and DNA ploidy, cytogenetics, and fluorescent in situ hybridization may provide valuable additional information for precise characterization of these neoplasms. Some of the ancillary studies may also be used for assigning these cases to prognostically significant subgroups. This information may also help in defining the most suitable chemotherapeutic regimens for these tumors. Since most of these special studies require only a small amount of cellular material, fine-needle aspiration biopsy is ideally suited for obtaining samples for these procedures. It is hoped that as cytogenetic and molecular techniques become available in many diagnostic laboratories, a comprehensive evaluation of aspiration biopsies from round cell malignant tumors, encompassing a precise pathologic diagnosis, determination of prognosis, and prediction of response to therapy, will be possible in a majority of cases. Diagn. Cytopathol. 1999;21:81-91.

Logistic regression analysis of small round cell neoplasms: a cytologic study

The diagnosis of small round cell neoplasms (SRCN) in children is difficult by both histologic and cytologic methods. These neoplasms are unified morphologically by the scanty cytoplasm surrounding relatively round nuclei containing a primitive chromatin pattern. Further categorization is achieved histologically by the recognition of architectural differentiation and cytoplasmic features. Numerous series and case reports documenting the cytologic features of SRCN have been published in the English-language literature, but relatively few studies have statistically analyzed the diagnostic utility of these features. Our logistic regression analysis of 59 cases of SRCN indicates that the presence of an extremely scanty cytoplasm favors the diagnosis of Ewing's sarcoma (P = 0.004), as does the positive expression of cytoplasmic vacuoles (P = 0.02). Strap or tadpole cells closely correlate with the diagnosis of rhabdomyosarcoma (P < 0.001). The positive expression of rosettes strongly supports the presence of a neuroblastoma (P < 0.001). The diagnosis of Wilms' tumor is confirmed by the expression of tubules (P < 0.001). The presence of lymphoglandular bodies strongly favors the diagnosis of lymphoma (P < 0.001). While some cytologic features are highly correlated with specific SRCN, these features are not invariably present, and definitive diagnosis may require immunohistochemical or ultrastructural analysis performed on cell block material.

Diagnostic value of tissue polypeptide-specific antigen (TPS) in neuroblastoma and Wilms' tumour

Although tissue polypeptide-specific antigen (TPS) has been described as a potentially useful serum marker of tumour activity in adult epithelial tumours, few data are available for childhood malignancies. Neuroblastomas and Wilms' tumours are the commonest types of solid malignancies found in the retroperitoneum of children. At this time, a widely used marker for Wilms' tumour is not available. Using an enzyme-linked immunosorbent assay (ELISA) kit, serum TPS levels in 23 children with neuroblastomas, nine with Wilms' tumours and 22 with benign tumours were evaluated to test the usefulness of the marker in identifying malignancies. Compared with healthy children (n = 110), the preoperative least-square means (LSM) of serum TPS were considerably elevated in both neuroblastoma (LSM = 209 U l(-1)) and Wilms' tumour (LSM = 235 U l(-1)), whereas values in benign tumours were only slightly elevated. Although the Wilms' tumours were associated with higher preoperative serum TPS levels, there was no statistically significant difference compared with neuroblastomas. Receiver operating characteristic analysis (ROC curves) showed a high sensitivity and specificity for both malignancies. Successful treatment resulted in decrease in TPS serum values. Serum TPS measurements in children presenting with abdominal masses can help in diagnosing the two commonest extracranial solid malignancies of childhood. Furthermore, TPS could acquire a pivotal role in monitoring therapy.

Immunohistochemical demonstration of Wilms tumour gene product WT1 in a canine "neuroepithelioma" providing evidence for its classification as an extrarenal nephroblastoma

An intradural extramedullary tumour, surgically removed from the spinal canal of a young dog with paraplegia, had the histological appearance of a nephroblastoma. Subsequent necropsy revealed no evidence of a renal primary tumour or of any other tumour. Similar tumours of the spinal canal have been described previously under a variety of names, in particular neuroepithelioma. With an antibody to the human Wilms tumour (nephroblastoma) gene product WT1, labelling of glomeruloid bodies, similar to glomerular podocytes in human fetal kidney, was demonstrated in the tumour. This finding strengthened the suggestion that it was a nephroblastoma.