Shaobo Zhang

Clear Cell Papillary Renal Cell Carcinoma : A Distinct Histopathologic and Molecular Genetic Entity

A group of renal tumors composed mainly of cells with clear cytoplasm arranged in papillary patterns and arising in end-stage kidneys has recently been identified. The aim of our study is to investigate the cytogenetic and immunohistochemical phenotypes of these unusual renal tumors, and of morphologically similar tumors arising in kidneys unaffected by end-stage renal disease. Seven tumors from 5 patients (age range: 53 to 64u2009y, mean: 60u2009y; 3 men and 2 women) were identified. Sections were obtained from paraffin blocks, including the tumors and adjacent non-neoplastic renal parenchyma. Interphase fluorescence in situ hybridization was performed with centromeric probes for chromosomes 3, 7, 17, Y, and with a subtelomeric probe for 3p25. Immunohistochemistry was performed with antibodies against cytokeratin 7, carbonic anhydrase IX, α-methylacyl-CoA racemase, CD10, and transcription factor E3. Four of the tumors were from patients who did not have end-stage renal disease. One patient had end-stage renal disease and presented with 3 morphologically identical tumors, composed of clear cells arranged in a mixture of cystic and papillary structures. Follow-up data were available from all patients and none showed recurrence or metastasis (mean follow-up: 24u2009mo). All 7 tumors (ranging from 4 to 50u2009mm in diameter) were stage pT1. All tumors lacked the gains of chromosome 7 and losses of chromosome Y that are typical of papillary renal cell carcinoma. Only 1 tumor showed gain of chromosome 17. Deletion of 3p, usually seen in clear cell renal cell carcinoma, was not detected. All tumors showed strongly positive immunohistochemical staining for cytokeratin 7 and carbonic anhydrase IX and negative immunostaining with antibodies against α-methylacyl-CoA racemase, CD10, and transcription factor E3. In conclusion, clear cell papillary renal cell carcinoma can arise in otherwise normal kidneys and in kidneys with end-stage renal disease. This tumor has immunophenotypic and genetic profiles distinct from those of either classic papillary or clear cell renal cell carcinoma, and should be considered a distinct entity in the spectrum of renal cell neoplasia.

Molecular Genetic Evidence for a Common Clonal Origin of Urinary Bladder Small Cell Carcinoma and Coexisting Urothelial Carcinoma

In most cases, small-cell carcinoma of the urinary bladder is admixed with other histological types of bladder carcinoma. To understand the pathogenetic relationship between the two tumor types, we analyzed histologically distinct tumor cell populations from the same patient for loss of heterozygosity (LOH) and X chromosome inactivation (in female patients). We examined five polymorphic microsatellite markers located on chromosome 3p25-26 (D3S3050), chromosome 9p21 (IFNA and D9S171), chromosome 9q32-33 (D9S177), and chromosome 17p13 (TP53) in 20 patients with small-cell carcinoma of the urinary bladder and concurrent urothelial carcinoma. DNA samples were prepared from formalin-fixed, paraffin-embedded tissue sections using laser-assisted microdissection. A nearly identical pattern of allelic loss was observed in the two tumor types in all cases, with an overall frequency of allelic loss of 90% (18 of 20 cases). Three patients showed different allelic loss patterns in the two tumor types at a single locus; however, the LOH patterns at the remaining loci were identical. Similarly, the same pattern of nonrandom X chromosome inactivation was present in both carcinoma components in the four cases analyzed. Concordant genetic alterations and X chromosome inactivation between small-cell carcinoma and coexisting urothelial carcinoma suggest that both tumor components originate from the same cells in the urothelium.

Evidence for Common Clonal Origin of Multifocal Lung Cancers

BACKGROUNDnLung cancer is the most common cause of cancer death in the United States. Multiple anatomically separate but histologically similar lung tumors are often found in the same patient. The clonal origin of multiple lung tumors is uncertain.nnnMETHODSnWe analyzed 70 lung tumors from 30 patients (23 females and seven males) who underwent surgical resection for lung epithelial tumors, of whom 26 had non-small cell carcinomas and four had carcinoid/atypical carcinoid tumors. All patients had multiple tumors (two to five) involving one or both lungs. Genomic DNA was extracted from paraffin-embedded tissue sections using laser capture microdissection and analyzed for loss of heterozygosity, TP53 mutations, and X-chromosome inactivation status. The percentage (95% confidence interval [CI]) of patients in whom there were concordant patterns of genetic alteration was calculated.nnnRESULTSnAll 30 case subjects showed loss of heterozygosity (LOH) in at least one and at most four of the six polymorphic microsatellite markers. Completely concordant LOH patterns between synchronous and metachronous cancers in individual patients were seen in 26 (87%) of 30 informative patients (95% CI = 75% to 99%). Identical point mutations were present in eight of 10 patients who exhibited TP53 mutation by sequencing. Tumors in 18 (78%) of 23 female patients (95% CI = 67% to 98%) showed identical X-chromosome inactivation patterns. Combining the results of LOH studies, TP53 mutation screening analyses, and X-chromosome inactivation data, we demonstrated that the multiple separate tumors in 23 (77%) of 30 patients (95% CI = 62% to 92%) had identical genetic changes, consistent with monoclonal origin of the separate tumors.nnnCONCLUSIONSnOur data indicate that the great majority of multifocal lung cancers have a common clonal origin and that multifocality in lung cancer represents local and regional intrapulmonary metastasis.

Renal Cell Carcinomas With Papillary Architecture and Clear Cell Components: The Utility of Immunohistochemical and Cytogenetical Analyses in Differential Diagnosis

Although histologic features enable an accurate diagnosis in most renal carcinomas, overlapping morphologic findings between some renal neoplasms make subclassification difficult. Some renal carcinomas show papillary architecture but are composed extensively of cells with clear cytoplasm, and it is unclear whether they should be classified as clear cell renal cell carcinomas or papillary renal cell carcinomas. We analyzed the immunohistochemical profiles and the cytogenetic patterns of 14 renal carcinomas showing papillary architecture in which there were variable amounts of cells with clear cytoplasm. The patients were 8 women and 6 men (mean age: 54u2009y). Immunohistochemistry and fluorescence in situ hybridization analysis distinguished 2 different groups. The first consisted of 10 renal cell carcinomas with strong immunoreactivity for α-methyl coenzyme A racemase, of which 9 also expressed cytokeratin 7. All of these neoplasms showed gains of chromosome 7 or 17 and chromosome Y was lost in all the male patients whereas 3p deletion was detected only in one case. In the other 4 renal cell carcinomas, cytokeratin 7 was not detected and α-methylacyl-CoA racemase was positive in only 1. In these neoplasms, no gain of chromosome 7 or 17 and no loss of chromosome Y were observed, whereas 3p deletion was detected in 3 of them. None of the 14 neoplasms showed immunoreactivity for TFE3. The combined use of immunohistochemistry and cytogenetics enabled us to provide a definitive diagnosis for 12 of 14 renal cell carcinomas with papillary architecture and clear cell components: 9 cases were confirmed to be papillary renal cell carcinomas and 3 cases were confirmed to be clear cell renal cell carcinomas. Despite these ancillary techniques, 2 cases remained unclassified. Our study establishes the utility of these procedures in accurately classifying the great majority of renal cell carcinomas with these findings.

Acquired cystic disease-associated renal tumors: an immunohistochemical and fluorescence in situ hybridization study

End-stage renal disease is associated with an increased incidence of renal cell neoplasms. Among these, recent studies have identified tumors with unusual histological patterns that do not fit into the categories recognized in the current classification system. These tumors often occur in kidneys with acquired cystic disease and are composed mainly of large eosinophilic cells arranged in solid, cribriform, acinar, or papillary patterns. They also contain deposits of calcium oxalate crystals. We investigated three eosinophilic epithelial tumors arising in kidneys with acquired cystic disease from three patients. Each of the tumors was composed of large eosinophilic cells arranged in solid, acinar, or tubulocystic architecture. Deposits of calcium oxalate crystals were present in each tumor. Hales colloidal stain showed a positive cytoplasmic reaction in one of the neoplasms. Immunohistochemistry displayed positive results for CD10 (3/3), AE1/AE3 (3/3), alpha-methylacyl-CoA racemase (2/3), CAM5.2 (2/3), and vimentin (1/3). Reactions for epithelial membrane antigen, cytokeratin 7, and high molecular weight cytokeratin (34βE12) were negative. Fluorescence in situ hybridization analysis showed no losses or gains of chromosomes 1, 2, 6, 10, or 17 in one tumor. There were gains of chromosomes 1, 2, and 6 in two tumors. One of these tumors also showed gains of chromosome 10. Eosinophilic renal cell tumors associated with acquired cystic disease have immunophenotypes and genetic profiles distinct from the renal cell neoplasms recognized in the current classification of renal cell neoplasia, and should be considered as a distinct clinicopathologic entity in the spectrum of renal cell neoplasia.

Epidermal growth factor receptor protein expression and gene amplification in small cell carcinoma of the urinary bladder

Purpose: Small cell carcinoma of the urinary bladder is a highly aggressive malignancy with an average life expectancy of only a few months. Epidermal growth factor receptor (EGFR) has been implicated in the pathogenesis and progression of many malignancies. This study was done to investigate EGFR protein expression and gene amplification in a large series of small cell carcinomas of the urinary bladder. Experimental Design: Fifty-two cases of urinary bladder small cell carcinoma were included in this study. Immunostaining for EGFR was done on paraffin-embedded tissue sections, and gene amplification for EGFR was done by fluorescence in situ hybridization. EGFR expression was correlated with clinicopathologic characteristics and clinical outcome. Results: All 52 patients, except 1, had advanced disease (T2 or above) at presentation. Immunohistochemically, positive EGFR expression was observed in 14 of 52 (27%) cases. No EGFR gene amplification was observed in any of 52 cases by fluorescence in situ hybridization. Forty cases had polysomy and the remaining 12 cases displayed disomy. No correlation between EGFR protein expression and gene amplification was shown. There was no correlation between EGFR expression and clinicopathologic characteristics. Conclusions: EGFR is expressed in a subset of urinary bladder small cell carcinomas; however, expression of EGFR does not correlate with clinicopathologic variables. At the molecular level, EGFR overexpression in small cell carcinoma of the urinary bladder does not seem to be caused by gene amplification. The expression of EGFR raises the possibility that EGFR may be a potential therapeutic target in the treatment of this malignancy.

Chromosome 12p abnormalities in dysgerminoma of the ovary: a FISH analysis.

Dysgerminoma is the most common malignant ovarian germ cell tumor and shares histological and immunophenotypical features with its testicular counterpart, seminoma. Chromosome 12p abnormalities are genetic hallmarks of testicular seminomas. Little is known about these genetic changes in dysgerminoma. We performed dual color fluorescence in situ hybridization (FISH) analyses with a centromeric α-satellite probe for chromosome 12 and a subtelomeric probe for 12p on paraffin-embedded tissue sections from 21 dysgerminomas and two gonadoblastomas. Chromosome 12p abnormalities were detected in 81% of dysgerminomas. In all, 57% of cases had only isochromosome 12p and 5% had only 12p overrepresentation. In all, 19% had both isochrome 12p and 12p overrepresentation. Gonadoblastomas were negative for isochromosome 12p or 12p overrepresentation. Chromosome 12p abnormalities are common in dysgerminoma of the ovary. FISH analyses for chromosome 12p abnormalities may be a useful diagnostic adjunct for confirming the diagnosis of dysgerminoma and for distinguishing it from nongerm cell malignancies that enter into the differential diagnosis.

Histopathological findings after treatment of prostate cancer using high-intensity focused ultrasound (HIFU)

High‐intensity focused ultrasound (HIFU) treatment is a novel minimally invasive therapeutic option for patients with localized prostate cancer. Little is known about the histological findings in prostate biopsies upon HIFU treatment.

Evidence for Polyclonal Origin of Multifocal Clear Cell Renal Cell Carcinoma

Purpose: Renal cell carcinomas are often multifocal. We investigated the genomic signatures of multifocal clear cell renal cell carcinoma to determine whether multiple tumors in the same kidney bear a clonal relationship to one another. Experimental Design: A total of 62 tumors from 26 patients who underwent radical nephrectomy were examined. All patients had multiple separate clear cell renal carcinomas. Loss of heterozygosity analyses were done using five microsatellite polymorphic markers that represent putative tumor suppressor genes on chromosome 3p14 (D3S1300), 7q31 (D7S522), 8p22 (D8S261), 9p21 (D9S171), and 17p13 (TP53). X chromosome inactivation analyses were also done on the renal tumors from the 10 female patients. Chromosome 3p deletion status was determined by dual color interphase fluorescence in situ hybridization analysis in all tumors. Results: Nineteen of the 26 (73%) patients with multifocal clear cell renal cell carcinoma showed allelic loss in at least 1 of 5 microsatellite loci in separate tumors analyzed. A disconcordant pattern of allelic loss between coexisting kidney tumors was observed in 7 cases. Six cases showed discordant 3p deletion patterns by dual color interphase fluorescence in situ hybridization analysis. Of the eight informative female cases studied by X chromosome inactivation, one showed a discordant nonrandom pattern of X chromosome inactivation. Overall, evidence of independent origin of the multifocal renal tumors was observed in 12 of 26 cases (46%). Conclusions: Our data suggest that in a significant number of cases of multifocal clear cell renal cell carcinoma, the spatially separate tumors are of different clonal origin and arise independently.

Renal Cell Neoplasms of Oncocytosis Have Distinct Morphologic, Immunohistochemical, and Cytogenetic Profiles

This study was undertaken to elucidate the genetic patterns of the renal cell neoplasms of oncocytosis and to compare them with those found in cases with multiple oncocytomas. Three cases of renal oncocytosis and 6 cases of multiple oncocytomas were analyzed. Fluorescence in situ hybridization analysis was performed with centromeric probes for chromosomes 1, 2, 6, 10, and 17 that are typically lost in chromophobe renal cell carcinoma but not in oncocytoma. Immunohistochemistry for cytokeratin 7, parvalbumin, and S100A1 was performed in all cases. Eleven tumors were present in the 3 kidneys with oncocytosis. One of these was a classic chromophobe renal cell carcinoma. In the other 10, none showed any chromosomal losses, whereas 3 showed gains of all 5 chromosomes and 1 had gains of chromosomes 2 and 10. The chromophobe renal cell carcinoma showed losses of chromosome 1, 6, 10, and 17. Twelve of 14 tumors from the patients with multiple oncocytomas showed no loss of any of the chromosomes 1, 2, 6, 10, or 17 and 2 had loss of chromosome 1. All the tumors from kidneys with renal oncocytosis showed strong parvalbumin immunoreactivity, whereas cytokeratin 7 and S100A1 expression were variable. In summary, the renal cell neoplasms of oncocytosis seem to have distinct morphologic, immunohistochemical, and cytogenetic profiles and likely are a distinct entity, not closely related to oncocytoma or chromophobe renal cell carcinoma.