RAS Family Gene Mutations, Clinicopathological Features, and Spread Patterns of Inverted Urothelial Papilloma of the Bladder

Inverted urothelial papilloma (IUP) is a benign neoplasm characterized by a downgrowth of the urothelium beneath the surface of morphologically normal urothelial cells; however, the molecular features of IUP and their association with clinicopathological characteristics are unclear. In this study, we aimed to investigate the mutational landscape, clinicopathological features, genotype-phenotype associations, and spread patterns of IUP. We performed targeted next-generation sequencing of 39 consecutive IUP cases, the largest series investigated to date, and identified oncogenic driver mutations in RAS family genes in 34 cases (87%). HRAS mutations were the most prevalent (28 cases), which included Q61R (15 cases), followed by KRAS (5 cases) and NRAS (1 case) mutations. Characteristic mutations observed in urothelial carcinoma, including those in FGFR3 , TP53 , or the TERT promoter, were absent. HRAS -mutated IUPs were associated with a history of smoking ( P = 0.017) and streaming morphology ( P < 0.001), corresponding to the trabecular subtype. In contrast, all KRAS -mutated IUPs occurred in never-smoking patients ( P = 0.001) and showed cystic changes in morphology ( P = 0.005), corresponding to the glandular subtype. RAS Q61R immunohistochemistry visually revealed the neoplastic nature of the overlying cells and distinct spread patterns of IUP cells within the surface, including pseudoinfiltrative spread. No recurrence or carcinoma development was observed in any of the IUP cases during the follow-up period. Thus, we confirmed the importance of RAS pathway activation in IUP pathogenesis, an association between RAS family gene mutations and IUP subtypes, and the spread patterns of IUP cells within the surface.

An in vitro model and the underlying pathways of sinonasal inverted papilloma development

Recently, the specific association between Sinonasal inverted papilloma (SIP) and EGFR exon 20 mutations has been reported. To investigate the link between specific EGFR mutations and SIP development, we established organotypic raft culture system using nasal polyp-derived immortalized NP2 (iNP2) cells expressing EGFR exon 20 mutants or an exon 19 mutant, and SIP-derived iIP4 cells harboring P772_H773insPYNP mutation. In the raft culture, iIP4 cells showed the inverted growth pattern characteristic to SIP. Interestingly, iNP2 cells expressing EGFR exon 20 duplication mutants, S768_D770dup and N771_H773dup, but not of EGFR exon 19 mutant, E746_A750del, showed the inverted growth pattern. Enhanced activation of the PI3K/AKT signaling pathway was observed in iNP2_S768_D770dup and iIP4 cells, while increased MAPK signaling was found in iNP2_N771_H773dup. Increased cell migration and invasion were found in all cells carrying EGFR mutations when compared to iNP2 cells, and this effect was inhibited by either PI3K or MEK inhibitor. Notably, iNP2 cells expressing the N771_H773dup mutant showed the highest migration and invasion abilities. These results suggest that specific mutations in EGFR exon 20 play a crucial role in SIP development, partially though hyper-activation of the PI3K/AKT and MAPK signaling pathways. This study presents the first in vitro model for SIP development, which could facilitate further investigations into SIP pathogenesis and preclinical studies for new therapeutic agents.

Human papillomavirus expression in relation to biological behavior, Ki-67 proliferative marker, and P53 prognostic marker in Schneiderian papilloma

Various malignant and benign tumors can arise in the sinonasal cavity, including inverted papilloma (IP), a benign neoplasm with unique clinical characteristics. However, the mechanisms involved in the recurrence, occurrence, and malignant transformation of IP remain debatable. This study aimed to investigate the impact of human papillomavirus (HPV) infections on IP by comparing the number of infections in cases with epithelial tissue dysplasia and explore the predictive role of proliferative and prognostic markers in dysplasia. Tissue blocks from 35 cases of sinonasal papilloma, collected between 2015 and 2021 from the laboratory archives of the Medical City of Ghazi Al-Hererri Hospital in Baghdad, Iraq, were immunohistochemically stained with monoclonal antibodies (mAbs) to detect Ki-67 and p53. A quantitative immunohistochemical analysis was conducted to analyze the results. Polymerase chain reaction (PCR) was performed to detect HPV genotypes 16/18 and 6/11 in the tissues. There was an insignificant increase in Ki-67 and p53 expression in inverted papillomas with dysplasia. HPV11 was the most prevalent genotype in 34.3% of the patients, followed by HPV16 and HPV18 in 31.4% of the patients for each virus. The least common virus detected was human papillomavirus 6 (8.6%), which did not show any significant association with the degree of dysplasia. Viral detection proliferation and apoptosis had no impact on tumor dysplasia amongst all the patients, showing no relationship with the evaluated cases.

Decreased Expressions of CK1α and PTEN in Sinonasal Inverted Papilloma

To investigate the diagnostic value of casein kinase 1α (CK1α) and phosphatase and tensin homolog (PTEN) in sinonasal inverted papilloma (SNIP), 42 control subjects and 56 SNIP patients were recruited in this study. Demographic and clinical characteristics, computerized tomography scans and endoscopic examinations were analyzed according to the Krouse staging system. Real-time quantitative-polymerase chain reaction and Western blotting were performed to detect CK1α and PTEN expression levels in different subgroups. Receiver operating characteristic and correlation analyses were conducted to assess their clinical significance in SNIP diagnosis. The expression levels of CK1α and PTEN were decreased in SNIP patients. Interestingly, the declined mRNA levels were consistent with the elevated Krouse staging and closely associated with the pathophysiological characteristics. Their expression levels also negatively correlated with neutrophil counts and positively correlated with lymphocyte counts in the blood of SNIP patients. This study suggests that CK1α and PTEN might be useful biomarkers for the occurrence and recurrence diagnosis of SNIP.

NGS-based miRNome identifies miR-449 cluster as marker of malignant transformation of sinonasal inverted papilloma

OBJECTIVE

identification of the miRNA expression profile in sinonasal inverted papilloma (SNIP) as a tool to evaluate the risk of transformation into sinonasal squamous cell carcinoma (SNSCC).

MATERIALS AND METHODS

paired tumour tissues and adjacent normal tissues were obtained from SNIP and SNSCC patients who had undergone surgical resection and used for next-generation sequencing (NGS)-based miRNome analysis. SNIP tissues with concomitant dysplasia (SNIP-DISP) were used as malignant transition samples. By comparing the deregulated miRNAs in SNIP and SNSCC, an miRNA cluster was identified and its physio- and clinical-pathological value was predicted.

RESULTS

NGS identified 54 miRNAs significantly down- and upregulated in SNIP. Among them, the miR-449 cluster was upregulated in SNIP and could differentiate the benign tumour from normal tissue. Notably, the miR-449 cluster was found to be significantly underexpressed in SNSCC, and the cluster markedly changed in SNIP during the malignant transition into SNSCC. miRNA enrichment analysis and GO analysis revealed that miR-449 is involved in apoptotic and cell proliferation pathways.

CONCLUSIONS

Our findings suggest that miR-449 may be involved in the molecular pathogenesis of SNIP and its malignant transformation into SNSCC. miR-449 might therefore be a useful tumour biomarker in patients with SNIP and may also have the potential to be used as a tool for detecting and monitoring the course of the possible malignant transformation.

Expression of Sp100 Protein in Human Papillomavirus-Associated Sinonasal Inverted Papilloma

OBJECTIVE

Sinonasal inverted papilloma (SNIP) is a benign tumor characterized by an aggressive growth, a tendency to recur, and an association with malignancy. However, the precise etiology of SNIP is still unknown. The objective of this study was to identify the expression pattern of speckled protein 100 (Sp100) in the malignant transformation (MT) of SNIP and its correlation with human papillomavirus (HPV)-16 and HPV-18 infections and other clinical features. This would further help in understanding the possible mechanisms for the development of SNIP.

METHODS

Individual nasal mucosa specimens from 40 patients (25 males and 15 females) and 10 inferior turbinate specimens as controls were included in the present study. The samples were divided into several sections for histopathological examination, HPV DNA detection, and immunohistochemical staining.

RESULTS

We observed that as SNIP progressed, the Sp100 protein expression was gradually downregulated, and SP100 localization changed from nucleus to the cytoplasm. Positive rate of HPV infection in the SNIP with MT group was higher than that in the other groups, and Sp100 expression was correlated to HPV infections and SNIP with MT. However, no correlation was observed between Sp100 expression and clinical features, such as age, gender, and smoking.

CONCLUSION

Positive rate of HPV infection is high in the SNIP with MT and has a correlation with Sp100 expression. In addition, the expression of Sp100 is downregulated in SNIP with MT, and Sp100 may play a role in the progression of SNIP.

Genetic mutation analysis of the malignant transformation of sinonasal inverted papilloma by targeted amplicon sequencing

BACKGROUND

The mechanism underlying the malignant transformation of inverted papilloma (IP) has not yet been elucidated.

METHODS

To clarify the genes responsible for the malignant transformation, we analyzed 10 cases of IP, 8 of IP with dysplasia, and 11 of squamous cell carcinoma (SCC) by targeted amplicon sequencing.

RESULTS

The number of mutant genes increased in the order of IP < dysplasia < SCC. Significant differences were observed in the mutation rates of three genes (KRAS, APC and STK11) in particular. TP53 was altered frequently in each group and might be involved in malignant transformation based on to the site of the mutation. A comparison of the genetic variants by region of IP tissue among patients with IP alone, and those with dysplasia or SCC revealed significant differences in the mutation rate of the KRAS gene.

CONCLUSION

Identification of genetic mutations in KRAS is effective for predicting the malignant transformation of IP.

Human Papilloma Virus (HPV) in Sinonasal Papillomas and Squamous Cell Carcinomas: A PCR-based Study of 60 cases

This study was carried out to observe the association of Human Papilloma Virus (HPV) with papillomas and squamous cell carcinomas of the sinonasal region. The present study was a hospital-based study conducted over a period of three years from May, 2014 to May, 2017 in the Department of Pathology, Government Medical College, Srinagar. A total of 196 cases of non-neoplastic and neoplastic lesions of nasal cavity and paranasal sinuses were observed during the study period. Out of total 196 cases, 102 were non-neoplastic and 94 were neoplastic. Of the 94 neoplastic lesions, 58 were benign and 36 were malignant. A total of 60 cases which included 38(63.33%) inverted papillomas, 12(20%) exophytic papillomas and 10 (16.66%) squamous cell carcinomas were included in the present study for HPV association. We studied the association of HPV with sinonasal papillomas and squamous cell carcinomas by polymerase chain reaction (PCR). HPV positivity was seen in 5(13.16%) out of 38 cases of inverted papillomas, whereas 4 out of 12(33.33%) exophytic papillomas tested positive for HPV. Out of 10 squamous cell carcinomas HPV positivity was seen in 2(20%) cases. Low risk HPV types 6 and 11 showed an association with sinonasal papillomas and oncogenic HPV types 16 and 18 with squamous cell carcinomas.

[Expression and significance of C/EBPα and CK10 in nasal inverted papilloma]

OBJECTIVE

The expression of C/EBPα, CK10 in nasal inverted papilloma (NIP) were detected in the study. Further discussed their significance in genesia, development and recurrence of NIP.

METHOD

Three groups including nasal cavity mucosae (NM 10 cases), nasal polyp (NP 20 cases) and NIP (30 cases) were selected in the study. Expretion of C/EBPα, CK10 were detected by immunohistochemisty PV-6000 method.

RESULT

(1) The different expression of C/EBPα and CK10 in the group of NM, NP and NIP was statistically significant (P < 0.05). (2) The different expression of C/EBPα, CK10 in the group of benign NIP and NIP with atypical hyperplasia was statistically significant (P < 0.05). (3) The different expression of C/EBPα and CK10 in the group of NIP with recurrence and NIP with no recurrence was statistically significant, P < 0.05, respectively. (4) Our result indicate that the relationship of C/EBPα and CK10 (r = 0.578, P < 0.01) was direct correlation. The difference was statistically significant.

CONCLUSION

In conclusion, the present results describe C/EBPα, CK10 expression in NIP and their possible implication in the regulation of tumor growth and differentiation. C/EBPα and CK10 production may prove useful in terms of a prognostic marker for the recurrence in nasal inverted papilloma.

[Significances of COX-2, p21, Ki-67 expression and HPV infection in nasal inverted papilloma]

OBJECTIVE

To investigate the significance of expression of COX-2, p21, Ki67 and HPV in nasal inverted papilloma.

METHOD

Detecting COX-2, p21, Ki-67 in 30 cases of nasal inverted papilloma (NIP), 20 cases of nasal polyps (NP) and 10 cases of normal nasal mucosa (NM) by two step immunohistochemical method, and HPV virus by flow-through hybridization method.

RESULT

The positive expression rate of COX-2 and Ki-67 in NIP, NP and NM group was decreased in turn, COX-2 had significant difference in the groups(χ2 = 30.00, P< 0. 05); the positive expression rate of Ki-67 had significant differences between NIP and NM group (χ2 = 8. 533, P<0. 05). The expression of COX-2 in NIP tissues was positively correlate with that of Ki-67 by using Spearman rank correlation analysis (r=0.78, P<0.05). Expression of p21 were not observed in NIP group. The positive rate of HPV was 26. 67% in 30 cases of NIP, all of HPV16 type.

CONCLUSION

COX-2, Ki-67 and HPV infection have certain correlation with the occurrence of NIP. The occurrence of NIP has relationship with inflammatory reaction mediated by COX-2. Ki-67 can well reflect the proliferation activity of tumor cells, and can be used to measure the proliferation rate of nasal inverted papilloma. The COX-2 and Ki-67 have a synergistic role in the pathogenesis of NIP. p21 has no significant relationship with the incidence of NIP. HPV infection is related to the pathogenesis of NIP, but not as a;major factor in the pathogenesis of NIP.

[The quantification and significance of muscle segment homeobox gene Msx2, human topoisomerase II-α, HPV16 and VEGF in sinonasal inverted papilloma]

OBJECTIVE

To investigate the quantification and significance of Msx2, topoII-α; HPV16 and VEGF in sinonasal inverted papilloma(SNIP), to study the correlation among the four factors,and to discover the relationship between Msx2 and topoII-α in the process of SNIP malignant transfomation.

METHOD

Real-time quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect the expression of Msx2, topoII-α, HPV16 and VEGF in 13 cases of sinonasal inverted papilloma (SNIP), 10 cases of sinonasal squamous cell carcinoma(NSCC) and 10 cases of inflammatory nasal polyp paraffin (INP)tissues. According to the pathology results SNIP were divided into mild dysplasia, moderate dysplasia and severe dysplasia. All the data were analysised by SPSS17. 0, P<0. 05 was refered to statistically significant difference.

RESULT

The mRNA level of Msx2, topoII-α, VEGF and HPV16 in SNIP, NSCC tissues were significantly higher than in the INP tissues (P<0. 05). The expression differences of Msx2, topoII-α, HPV16 and VEGF mRNA level in SNIP tissues which were divided into three groups according to their pathological results,were all statistically significantly different between any two of the three groups (P< 0. 05). Using Pearson correlation coefficient analysis,we found positive correlation between any two of the mRNA level of Msx2, topoII-α, VEGF and HPV16 (P<0. 05).

CONCLUSION

Msx2 and topoII-α may play an important role in the process of SNIP Malignant transformation,which may be new targets for gene therapy of SNIP and NSCC.

HRAS mutations are frequent in inverted urothelial neoplasms

Inverted urothelial papilloma (IUP) is an uncommon neoplasm of the urinary bladder with distinct morphologic features. Studies regarding the role of human papillomavirus (HPV) in the etiology of IUP have provided conflicting evidence of HPV infection. In addition, little is known regarding the molecular alterations present in IUP or other urothelial neoplasms, which might demonstrate inverted growth pattern like low-grade or high-grade urothelial carcinoma (UCA). Here, we evaluated for the presence of common driving somatic mutations and HPV within a cohort of IUPs, (n = 7) noninvasive low-grade papillary UCAs with inverted growth pattern (n = 5), and noninvasive high-grade papillary UCAs with inverted growth pattern (n = 8). HPV was not detected in any case of IUP or inverted UCA by either in situ hybridization or by polymerase chain reaction. Next-generation sequencing identified recurrent mutations in HRAS (Q61R) in 3 of 5 IUPs, described for the first time in this neoplasm. Additional mutations of Ras pathway members were detected including HRAS, KRAS, and BRAF. The presence of Ras pathway member mutations at a relatively high rate suggests this pathway may contribute to pathogenesis of inverted urothelial neoplasms. In addition, we did not find any evidence supporting a role for HPV in the etiology of IUP.

Downregulation of DLEC1 in sinonasal inverted papilloma and squamous cell carcinoma

OBJECTIVE

Inverted papilloma is associated with sinonasal squamous cell carcinoma. This study aimed to investigate the epigenetic regulation of the tumour suppressor gene DLEC1 in inverted papilloma and sinonasal squamous cell carcinoma.

METHODS

DLEC1 gene expression was investigated by quantitative real-time polymerase chain reaction (QRT-PCR) in normal mucosa, inverted papilloma, and squamous cell carcinoma tissues. Methylation-specific PCR and subsequent autosequencing were also used to examine the methylation status of DLEC1 promoter and the involved mechanism. DLEC1 expression in a large validation set was evaluated by immunohistochemistry (n  =  25 in each group).

RESULTS

DLEC1 was downregulated in inverted papilloma and squamous cell carcinoma tissues compared to normal mucosa (p < .01 in QRT-PCR and immunohistochemistry), with squamous cell carcinoma more repressed (p < .05 in QRT-PCR and immunohistochemistry) than inverted papilloma tissues. DLEC1 promoter hypermethylation was found in squamous cell carcinoma tissues.

CONCLUSION

Repression of DLEC1 in squamous cell carcinoma tissues is associated with promoter hypermethylation. DLEC1 is downregulated in sinonasal squamous cell carcinoma and inverted papilloma and has a distinct mechanism.

[Expression and significance of Msx2 and topo II-alpha in sinonasal inverted papilloma]

OBJECTIVE

To investigate the expression and significance of muscle segment homeobox2 (Msx2) and topo II-alpha in sinonasal inverted papilloma (SNIP), and the relationship in the process of malignant transformation of SNIP.

METHOD

Immunohistochemical method was used to detect the expression of Msx2 and topo II-alpha in 32 cases of SNIP, 30 cases of inflammatory nasal polyp (INP) and 30 cases of SNIP with carcinoma. According to the pathology results, SNIP were divided into mild atypical hyperplasia, moderate atypical hyperplasia and severe atypical hyperplasia.

RESULT

The mean optical density of Msx2 in SNIP and SNIP with carcinoma tissues were 0.2183 +/- 0.0598 and 0.2521 +/- 0.0761,which were significantly higher than 0.1878 +/- 0. 0372 in the INP tissue (P<0.05 or 0.01). The mean optical density of topo II-alpha in SNIP and SNIP with carcinoma tissues were 0.2303 +/- 0.0397 and 0.2666 +/- 0.0483, which were significantly higher than 0.1978 +/- 0.0388 in the NIP tissue (P<0.01). There were significant difference of Msx2 and topo II-alpha in SNIP between any two of the three groups divided according to pathological morphology (P<0.01 or 0.05). The expression of Msx2 and topo II-alpha in SNIP were positively correlated (P<0.05).

CONCLUSION

Msx2 and topo II-alpha may play an important role in the occurrence and development of SNIP. So it can be used as new therapeutic targets.

[Expression and significances of FSCN1 and HGF in nasal inverted papilloma]

OBJECTIVE

To study the expressions of FSCN1 and HGF in nasal inverted papilloma (NIP) and explore their role in occurrence and development of this disease.

METHOD

Immunohistochemical method was used to determine the expression of FSCN1 and HGF in 12 cases of chronic hypertrophic rhinitis, 40 cases of NIP and 14 cases of NIP with malignant transformation.

RESULT

FSCN1 was expressed in 52.5% of NIP, 78.6% of NIP with malignant transformation and 8.3% of inferior turbinate of chronic hypertrophic rhinitis. Expression of FSCN1 was significantly higher in NIP and NIP with malignant transformation than in inferior turbinate (P<0.05). HGF was expressed in 85.7% of NIP with malignant transformation and 8.3% of inferior turbinate. Expression of HGF was significantly higher in NIP with malignant transformation than in inferior turbinate (P<0.05). HGF was expressed in 40.0% of NIP,which was higher than that of inferior turbinate. Expression of HGF was positively related to expression of FSCN1 in NIP and NIP with malignant transformation.

CONCLUSION

The abnormal expression of FSCN1 and HGF may be closely correlated with NIP and its malignant process. Analysis of FSCN1 and HGF expression in NIP may be useful in predicting malignant transformation.

[Significance and expression of VEGF and its receptor in nasal inverted papillomas and the correlation with malignant phenotype]

OBJECTIVE

To determine the expression of vascular endothelial growth factor (VEGF) and their receptor in nasal inverted papillomas (NIP) and to clarify the function of VEGF in the occurrence of NIPs and the correlation with malignant phenotype.

METHOD

VEGF and its receptor (flk-1), expression were examined by immunohistochemistry using LSAB method in sections of NIP from 48 patients and squamous carcinoma from 8 patients.

RESULT

All the epithelium together with the adjacent vascular and stroma,expressed increased positive staining of VEGF and flk-1 with the degree of atypical hyperplasia in epithelium. The VEGF/flk-1 expression in epithelium was significantly stronger in severe atypical hyperplasia than that in mild atypical hyperplasia, and same in mild atypical hyperplasia than in NIPs (P<0.01).

CONCLUSION

VEGF/flk-1 participate in the growth of NIPs. The enhanced VEGF/flk-1 in the epithelium may be identified as one of the parameters in judging malignant transformation of NIPs.

[Urothelial hyperplastic lesion with endophytic growth pattern: a clinicopathologic study]

OBJECTIVE

To study the clinicopathologic features of urothelial hyperplastic lesion with an endophytic growth pattern and the role of immunohistochemistry and multitargeted fluorescence in situ hybridization (FISH) in the differential diagnosis.

METHODS

Forty-one cases of urothelial lesions exhibiting endophytic growth patterns were reviewed and reclassified as inverted papilloma, urothelial carcinoma with an endophytic growth pattern, and florid von Brunn nest. The gains of chromosomes 3, 7, and 17 and loss of 9p21 was detected by FISH, and performed immunohistochemical staining for CK20, p53, and Ki-67. Follow-up data of 12 cases were obtained.

RESULTS

(1) Twelve inverted papillomas sized 1.2 cm in average, consisted of anastomosing cords and nests with uniform width distribution involving the lamina propria, the central portion contained streaming cells with squamous metaplasia, and the periphery showed palisading. No or rare atypia and mitosis were found. Focal exophytic papillary component lined by less than 6 layers of normal urothelium were observed in 4 cases. (2) Twenty-four urothelial carcinomas with an endophytic growth pattern sized 2.1 cm in average, demonstrated the similar architecture with inverted papilloma, but exhibited thick columns and variable thickness of the cords, irregular size and shape of large nests with transition into solids. Mild to moderate cytologic atypia was shown, and mitotic figures ranged 1 to 8 per 10 HPFs. Exophytic papillary component was not observed in 3 cases, but the superficial urothelium showed dysplasia, while coexisted exophytic component in other cases was associated with low malignant potential or low grade tumor. (3) Five florid von Brunn nests sized 0.9 cm in average, had normal or hyperplastic urothelium, variable nests with cysts compacted in lamina propria, no cytologic atypia and mitosis. Twenty-one of 24 (79.1%) urothelial carcinomas with an endophytic growth pattern displayed abnormally positive results by multitargeted FISH, whereas all inverted papillomas and florid von Brunn nests were negative. Immunohistochemically, CK20 was weakly positive in 2 cases of urothelial carcinoma with an endophytic growth pattern, and negative in all inverted papillomas and florid von Brunn nests. p53 weakly stained 5% to 50% nuclei of the tumor cells in 16 cases of urothelial carcinomas with an endophytic growth pattern and 1 inverted papilloma. 1%-5% tumor cells expressed Ki-67 in urothelial carcinoma with an endophytic growth pattern, and less than 1% in inverted papilloma and florid von Brunn nests. Follow-up study revealed that 2 cases of urothelial carcinoma with an endophytic growth pattern had developed invasive carcinoma, underwent cystectomy, and metastasized remotely. No recurrence occurred in cases of inverted papilloma.

CONCLUSIONS

Benign and malignant urothelial lesions with an endophytic growth pattern present histologic overlapping. Urothelial carcinoma with an endophytic growth pattern displays unique characteristics in morphology and immunohistochemistry. Multitargeted FISH analysis is helpful in the differential diagnosis.

Expression of p53, p16INK4A, pRb, p21WAF1/CIP1, p27KIP1, cyclin D1, Ki-67 and HPV DNA in sinonasal endophytic Schneiderian (inverted) papilloma

CONCLUSIONS

Human papilloma virus (HPV) was associated with sinonasal inverted papilloma (SIP) in 14/20 (70%) patients with a prevalence of HPV 6/11; alterations of the cell cycle proteins were statistically significant.

OBJECTIVES

We investigated SIPs relationships between HPV infection and aberrant expression of cell cycle proteins.

MATERIALS AND METHODS

Twenty SIPs were evaluated for p53, p16(INK4a), pRb, p21(WAF1), p27(Kip1), cyclin D1 and Ki-67 expression by immunohistochemistry. HPV was investigated by polymerase chain reaction (PCR).

RESULTS

HPV DNA was detected in 14/20 patients with inverted papillomas (IPs) (70%). The majority of tumours showed strong p16, p21, p27, pRb and cyclin D1 staining and little or no p53 expression. Tumours harbouring dysplasia were significantly more likely to be p53-positive and exhibit up-regulated p21 and p27, and showed altered intensity and distribution of reactive cells into and through the epithelium. Dysplastic epithelium was strongly reactive for p16 and the MIB 1 labelling index was almost 20%. These findings were associated with expression of p53 in the same zones. Comparing the p53 reactivity with the presence of HPV DNA, SIPs were stratified as follows: HPV + p53-, 12 (63.15%); HPV + p53+, 2 (10.52%); HPV - p53+, 3 (15.78%) and HPV - p53-, 2 (10.52%). Statistical analysis showed that HPV presence correlated with p53-positive immunostaining (p=0.045).

Low frequency of molecular changes and tumor recurrence in inverted papillomas of the urinary tract

AIM

Inverted papilloma (IP) of the urinary tract can be difficult to distinguish from noninvasive urothelial carcinoma with prominent inverted growth pattern (invNIUC). Ancillary markers may help to resolve such cases and clarify the reported malignant potential of some IPs.

METHODS

Eighty-nine urothelial lesions initially diagnosed as IP were reviewed by 4 experienced urologic pathologists and studied immunohistochemically (Ki67, p53, CK20, MSH2, MLH1, and MSH6). Mutations of the FGFR3 gene, deletions (loss of heterozygosity) of 9p, 9q, and 17p, microsatellite instability, and elevated microsatellite instability at selected tetranucleotides were also analyzed.

RESULTS

Considerable interobserver variability in histopathologic diagnoses was noticed. Only 62 (69.7%) initial diagnoses were confirmed by the review pathologists whereas 23 tumors (25.8%) were redefined as invNIUC. Molecular analyses revealed infrequent alterations in IPs, including microsatellite instability (1.8%), elevated microsatellite instability at selected tetranucleotides (13.2%), FGFR3 mutations (9.8%), 9p deletions (3.9%), 9q deletions (13.2%), 17p deletions (5.1%), nuclear p53 accumulation (18.9%), and aberrant immunostaining for MSH2 (5.8%), MLH1 (11.8%), and MSH6 (3.8%). IP and invNIUC differed in FGFR3 mutations and Ki-67 labeling index (P<0.001 each), and 9q loss of heterozygosity (P=0.03). There were fewer recurrences in IP (5.4%) compared with invNIUC (40.9%; P<0.0001).

CONCLUSIONS

IP is a benign lesion that lacks specific genetic alterations found in exophytic noninvasive papillary urothelial tumors. These lesions could be reactive in nature, perhaps secondary to chronic inflammation or a neoplastic process that lack specific genetic alterations. Nevertheless given the clinical and molecular data of this study a conservative clinical approach is appropriate.

Do nasal polyps and inverted papilloma have similar disorders in cell cycle regulation?

BACKGROUND

The aim of this study was to determine the expression of cell cycle regulation genes in patients with inverted papilloma (IP) and compare this with expression in patients with nasal polyps (NPs).

METHODS

Tissue from 18 patients with IP and 5 patients with NPs were stained by immunohistochemistry techniques for p53 and p27. Measurement of the gene expression was performed by three assessors, who we blinded with respect to the specimens.

RESULTS

The mean score for p53 expression (3.33) was significantly higher in the IP group than the NP group (1.46). The mean difference between IP and NPs was 1.80 (CI, 1.15-2.46; p = 0.003). Additionally, we showed in a number of individuals variation in the p53 expression within the same specimen. There was no difference in the mean scores for p27, with the mean difference 0.79 (CI, 0.30-1.89; p = 0.147).

CONCLUSION

Our study established a significantly increased expression of p53 in IP when compared with NPs. Additionally, there appear to be two different cell populations identified within the same specimens, which exhibited variation in their p53 expression.

Inverted papilloma of the urinary bladder: a molecular genetic appraisal

Inverted papilloma of urinary bladder is an uncommon urothelial neoplasm. Its relationship to urothelial carcinoma is controversial. Little is known of the genetic abnormalities of inverted papilloma. To better understand its genetics, we analyzed 39 inverted papillomas, including 36 from men and three from women, for loss of heterozygosity (LOH). We examined four polymorphic microsatellite markers located on chromosome 9q32-33(D9S177), chromosome 9p22 (IFNA), chromosome 3p14.2 (D3S1300) and chromosome 17p13.1 (TP53), where genetic alterations occur frequently in urothelial carcinomas. Additionally, the status of inactivation of X-chromosome was examined in three female patients. The frequency of LOH in informative cases was 8% (3 of 37) for D9S177, 10% (4 of 38) for TP53, 8% (3 of 37) for IFNA and 8% (3 of 36) for D3S1300. In the analysis of X-chromosome inactivation, all three cases yielded informative results and one had nonrandom inactivation of X-chromosomes. The monoclonal origin demonstrated in the study of X-chromosome inactivation indicates the clonal process of inverted papilloma; however, the low incidence of LOH supports the view that inverted papilloma in urinary bladder is a benign neoplasm with molecular genetic abnormalities different from those of urothelial carcinoma.

[The expression of nm23-H1 in the investing papilloma and it's cancerated tissue of nasal cavity and parasinuses]

OBJECTIVE

To investigate the role of the nm23-H1 protein in the development of investing papilloma and it's cancerated tissue in nasal cavity and parasinuses.

METHOD

The expression of nm23-H1 protein was measured by immunohistochemistry in twenty-five cases with investing papilloma and twenty-one cases with cancerated investing papilloma in nasal cavity and parasinuses and fourteen cases with chronic sinusitis.

RESULT

The expression of nm23-H1 in the investing papilloma was higher than that in cancerated investing papilloma tissue, the positive rate was 72% and 42% respectively in the two groups, P < 0.05. The expression of nm23-H1 in the investing papilloma was higher than in the chronic sinusitis, the positive rate of the latter was 14.3%, P < 0.05.

CONCLUSION

The lower expression the nm23-H1 protein in the cancerated tissue of investing papilloma was related to the infiltration and canceration.

Detection of human papillomavirus DNA in oral inverted ductal papillomas

AIMS

To determine the presence or absence of human papillomavirus (HPV) DNA in oral inverted ductal papillomas (IDPs) using in situ hybridisation (ISH), and to analyse all cases for histological features of HPV infection.

METHODS

Six cases were retrieved from archival material and paraffin wax blocks were submitted for the detection of HPV DNA by means of ISH. A wide spectrum probe for HPV subtypes 6, 11, 16, 18, 31, 33, 45, 51, and 52 was used initially. Cases that were positive using this wide spectrum probe were further subtyped using HPV type specific probes (6/11, 16/18, and 31/33). The histological features of all tumours were analysed using routine microscopy.

RESULTS

Of the six cases of oral IDP identified, three were positive for HPV subtypes 6/11. All positive cases showed histological features of HPV infection (koilocytosis, papillomatosis, binucleated keratinocytes, and abnormal mitosis) in both the surface and the inverted epithelium. The three cases that tested negative for HPV DNA also exhibited focal histological features of HPV infection (two in the surface epithelium and one in the endophytic epithelium).

CONCLUSIONS

These are the first documented cases of oral IDP to demonstrate positivity for HPV DNA and also to show histological features of HPV infection.

p21, p53, and p27 Kip1 alterations in benign and malignant tumors of sinonasal epithelium

OBJECTIVE

The goal of this study was to investigate alterations of cell cycle-related molecules, including p27, p21, and p53, in inverted papillomas (IPs) and squamous cell carcinomas (SCCs) of the sinonasal epithelium. Study design Sixteen IPs and 6 SCCs of the sinonasal epithelium, surgically resected at Istanbul Faculty of Medicine, Department of Otorhinolaryngology, from 1992 to 2000 were immunohistochemically investigated (p27, p21, and p53).

RESULTS

A significant decrease in p27 nuclear staining was observed for SCCs of paranasal sinus compared with inverted papillomas (P = 0.0072). In SCCs there was no association between p27 expression and the presence of keratinization and tumor grade. p21 and p53 expressions were not associated with IPs (dysplastic and nondysplastic) and SCCs.

CONCLUSION

Reduced levels of p27 expression correlate with increased cell proliferation in tumors of sinonasal region. Our findings indicate that p27 immunohistochemistry can be recommended to analyze the dysregulation of cell kinetics in these tumors.

Inverted sinonasal papilloma--a report of 31 cases and review of the literature

Inverted papilloma is an epithelial neoplasm of the lateral nasal wall and adjacent sinuses characterized by a marked propensity for recurrence and a significant association with carcinoma. In this retrospective study we present 31 cases treated by our departments between 1982 and 1999. The aim was to compare our results to those of other authors especially regarding surgical management. The male to female ratio of these patients was 2:1 and most patients were in the 6th and 7th decades of life. Conservative surgery was used in most cases as the initial treatment. The overall recurrence rate was low and there were 3 cases associated with carcinoma. We conclude that the results of conservative surgery in selected cases are comparable to those using radical methods. A review of the literature is presented and particular attention is dedicated to the literature concerning analysis of p53 expression, HPV and Epstein-Barr infection and apoptosis in inverted papilloma.

Expression of p53 in inverted papilloma and malignancy associated with inverted papilloma

OBJECTIVE

To determine the association of p53 protein in malignant cases of inverted papilloma compared with cases of benign inverted papilloma of the sinonasal tract.

DESIGN

Case-control study of archived pathologic material.

SETTING

Tertiary care hospital.

METHODS

Archived pathologic material of cases of malignancy associated with inverted papilloma and controls of benign inverted papilloma were obtained from Mount Sinai Hospital. These were subjected to immunohistochemistry for p53. Clinical correlation was obtained by retrospective chart review.

MAIN OUTCOME MEASURES

Staining of pathologic specimens for p53 and survival or recurrence.

RESULTS

Four of the five cases of malignancy associated with inverted papilloma demonstrated overexpression of p53. None of the benign cases of inverted papilloma demonstrated overexpression. Only two of the five patients with malignancy associated with inverted papilloma were alive at 2 years.

CONCLUSIONS

Overexpression of p53 may serve as a marker for malignant transformation of inverted papilloma.

Inverted urothelial papilloma: is ploidy, MIB-1 proliferative activity, or p53 protein accumulation predictive of urothelial carcinoma?

BACKGROUND

Inverted urothelial papilloma is an unusual neoplasm of the urinary tract. Although the association between inverted urothelial papilloma and urothelial carcinoma is not entirely clear, many studies indicate that patients with inverted papilloma are at increased risk for the development of urothelial carcinoma. In addition, aneuploid inverted papillomas have been associated with the subsequent development of urothelial carcinoma. The objective of this study was to determine whether ploidy, MIB-1 proliferative activity, or p53 protein staining in inverted papilloma were predictive of urothelial carcinoma.

METHODS

Fifty-one cases of inverted papilloma were retrieved from the Tissue Registry of the Mayo Clinic. Clinical records were reviewed for patient age, length of follow-up, and history of urothelial carcinoma (defined as carcinoma prior to, concurrent with, or subsequent to the diagnosis of inverted papilloma). DNA ploidy analysis was determined using Feulgen stained sections from paraffin embedded tissues using an image analysis system. Quantitation of MIB-1 proliferative activity and p53 immunostaining was determined similarly using immunoperoxidase stained sections from paraffin embedded tissues.

RESULTS

The mean age at diagnosis of inverted papilloma was 63.9 years (range, 37-87 years), and there were 39 men and 12 women. Patients were followed for a mean of 56.5 months (range, 1-252 months). Tumors ranged in size from 0.2 to 4.3 cm (mean, 0.9 cm). Eight patients (15.7%) had a prior, concurrent, or subsequent noninvasive World Health Organization and International Society of Urologic Pathology (WHO/ISUP) papillary neoplasm of low malignant potential or papillary carcinoma of low grade (formerly WHO Grade 1 or 2 papillary urothelial carcinoma). Inverted papillomas in patients with a history of urothelial carcinoma were all diploid and had a mean MIB-1 activity of 6.3% (range, 0.04-24.8%) and mean p53 protein staining of 12.6% (range, 0.5-24.9%). These inverted papillomas ranged in size from 0.3 to 1.0 cm (mean, 0.5 cm). Inverted papillomas in patients without a history of urothelial carcinoma were aneuploid in 6 cases (14.3%) and diploid in the remaining cases. These inverted papillomas had a mean MIB-1 activity of 1.6% (range, 0.06-9.0%) and mean p53 protein staining of 9.7% (range, 0.05-38.0%). Tumor size ranged from 0.2 to 4.3 cm (mean, 1.0 cm). There were no statistically significant differences in MIB-1 activity, p53 protein staining, ploidy, and morphologic features between inverted papillomas in patients with and without a history of urothelial carcinoma.

CONCLUSIONS

Ploidy, MIB-1 proliferative activity, and p53 immunostaining in inverted urothelial papilloma were not useful in identifying patients who had a history of urothelial carcinoma.

Inverted sinonasal papilloma : a molecular genetic appraisal of its putative status as a Precursor to squamous cell carcinoma

Inverted papilloma (IP) is a proliferative lesion of the epithelium lining the sinonasal tract. Although IP often recurs after surgical excision and is sometimes associated with squamous cell carcinoma of the sinonasal cavity (SNSCC), its presumed neoplastic nature and putative role as a precursor to squamous cell carcinoma have not been confirmed at the molecular genetic level. We analyzed the pattern of X chromosome inactivation in IPs from nine female patients. Inactivation of a single allele is seen in monoclonal proliferations and may be indicative of a neoplastic process. We also analyzed 28 IPs and 6 concurrent SNSCCs for loss of heterozygosity (LOH) on chromosomal arms 3p, 9p21, 11q13, 13q11, and 17p13. Losses at these loci occur frequently during neoplastic transformation of the upper respiratory tract and can be detected in squamous cell carcinomas and the progenitor lesions from which they arise. X chromosome analysis was informative in four of the nine IPs. All four lesions demonstrated a monoclonal pattern of inactivation. LOH was not detected in any nondysplastic areas from the 28 IPs, but LOH at one or more chromosomal loci was present in all six of the concurrent SNSCCs. We conclude that IPs are monoclonal proliferations, yet they do not fit the profile of a prototypic precursor lesion. Unlike squamous epithelial dysplasia, IPs do not routinely harbor several of the key genetic alterations that are associated with malignant transformation of the upper respiratory tract.

Apoptosis and p53 in inverting papilloma of the sinonasal tract

The objective of this study was to identify apoptotic bodies and p53 positivity in inverting papilloma lesions to study these two as biomarkers in premalignant lesions. Archival specimens of 15 patients with inverting papilloma between the years 1992 and 1995 were retrieved. In situ end labeling technique was used to identify apoptotic bodies. Immunohistochemistry was used to detect p53 in the same specimens. The clinical course was evaluated conducting a retrospective chart review in these patients. Compared to normal epithelium, inverting papilloma lesions had a greater proportion of apoptotic bodies, which was nearly statistically significant (average 0.506/100 cells for inverting papilloma compared with 0.1/100 cells for the normal surrounding tissue). Four cases of inverting papilloma were p53 positive. There was, however, no association between p53 positive staining and the apoptotic rate. The minimum follow-up for patients was 2 years. All had a uniformly good clinical outcome with only one patient who was p53 positive showing concurrent squamous cell carcinoma. We concluded that inverting papilloma contained a higher average number of apoptotic bodies compared with normal surrounding sinonasal tissue. This showed a trend toward a positive between the apoptotic rate and premalignancy, suggesting both increased cellular proliferation and increased cell death may occur in such lesions. In this study p53 did not show a positive association with the apoptotic rate, suggesting that p53 may not be directly involved in the apoptotic regulatory pathway in inverting papillomas.

[Expression of ras, p53, proliferating cell nuclear antigen in squamous cell carcinoma of maxillary sinus and their significance]

OBJECTIVE

To determine the expression of ras, p53 and proliferating cell nuclear antigen (PCNA) in squamous cell carcinoma(SCC), inverting papilloma(IP), inflammatory mucosa(IM) of maxillary sinus and analyze the correlation between their expression and the clinicopathological characters and prognosis of SCC of maxillary sinus(SCCMS).

METHODS

Expression of ras, p53 and PCNA was determined in 40 cases of SCC, 20 cases of IP and 10 cases of IM of maxillary sinus with immunohistochemical technique.

RESULTS

Expression of ras was correlated with differentiation of SCCMS, it was more frequent in well differentiated SCC than in poorly differentiated SCC. Expression of p53 was only present in SCCMS, there was not expression of p53 in IP and IM of maxillary sinus. The patients with high PCNA index SCCMS had a poorer prognosis than those with low PCNA index in SCCMS.

CONCLUSION

p53 protein may be a diagnostic marker in SCCMS. Measurement of PCNA index may be helpful in estimating prognosis and directing clinical treatment in SCCMS.

Identification of p53 and human papilloma virus in Schneiderian papillomas

Schneiderian papilloma of the nose is an unusual neoplasm with the propensity for local tissue destruction, recurrence, and malignant degeneration. Human papilloma virus (HPV) is related to a subset of sinonasal papillomas and has been implicated in the pathogenesis of cancer by interaction with the host p53 protein. Detection of p53 and HPV could be clinically useful as tumor markers for lesions with oncogenic potential. Thirty specimens for p53 were studied and nine (30%) stained positive. HPV was detected in six (20%). In the presence of p53, an odds ratio for carcinoma was 1.19:1, or 19% higher than expected. In the presence of HPV the odds ratio for carcinoma was 11.5:1, or 11.5 times higher than expected. In the presence of HPV an odds ratio for finding an elevated amount of p53 was 2.2:1. The data support the hypothesis that HPV and p53 may interact in a novel manner and elevate the risk for neoplasia.

p53 alteration and human papilloma virus infection in paranasal sinus cancer

BACKGROUND

Inverted papilloma (IP) of the paranasal sinus is a benign neoplastic condition that can be associated with squamous cell carcinoma (SCC). To understand the etiology of the disease better, paranasal sinus tumor specimens were examined for alterations in either p53 protein expression or genomic DNA sequence, and for infection by human papilloma virus (HPV).

METHODS

Tumor specimens were categorized as follows: benign, nondysplastic IP; IP with dysplasia; SCC arising within IP; or SCC without IP. Sections of each tumor specimen were stained for p53 protein overexpression, and mutations in exons 5-9 of the p53 gene were determined in DNA purified from all tumor samples. HPV infection was screened by degenerate polymerase chain reaction (PCR) amplification and typed by multiplex PCR and direct DNA sequencing of PCR-amplified HPV sequences.

RESULTS

Altered p53, either in genetic sequence or protein overexpression, was observed in 0 of 7 benign, nondysplastic IP specimens. A significantly higher p53 alteration incidence was observed for IP specimens exhibiting dysplasia (57%; P < 0.05) and IP specimens that were associated with SCC (75%; P < 0.025). HPV sequences were detected in 9 of 24 (38%) tumor specimens, 78% of which were of the oncogenic HPV16 strain. A significantly higher incidence (P < 0.05) of HPV infection was observed in IP tumors exhibiting dysplasia or containing SCC than in nondysplastic IPs. None of the p53-mutated tumors were infected with oncogenic HPV16.

CONCLUSIONS

These data suggest that p53 alterations and/or HPV infection are associated predominantly with IPs exhibiting evidence of dysplasia or IPs associated with SCC, but not in nondysplastic, benign IPs. In addition, an inverse correlation may exist between oncogenic HPV infection and p53 alterations in paranasal sinus tumors. The authors postulate that patients with IPs containing altered p53 may be at increased risk for SCC of the paranasal sinus.

Inverted papillomas of the paranasal sinuses and the nasal cavity: DNA indices and HPV infection

Inverted papillomas are rare tumors of the nasal cavity and paranasal sinuses. These tumors are commonly regarded as benign lesions; nevertheless, malignant transformation occurs in up to 13% of cases. In the present retrospective study, specimens from 21 patients with inverted papillomas of the paranasal sinuses and the nasal cavity were investigated in order to analyze the distribution of genetic imbalance and to classify chromosomal aneuploidy in these tumors as a predictor for their biological behavior. Currently, human papilloma viruses (HPVs) are accepted as tumor-inducing and -promoting agents involved in benign and malignant tumors of mucosal tissues in the upper aerodigestive tract. To date more than 80 HPV types have been identified by differences in the nucleotide sequences. Several types (e.g., HPV16, HPV18) are associated with an increased risk for developing cancer. Other types (e.g., HPV6/11) are identified more frequently in benign lesions of stratified mucous membranes. We detected HPV genomes by universal and specific primer polymerase chain reaction. Using degenerated primers derived from the L1 major envelope gene, an amplification of HPV DNA fragments of the correct size was observed in 7 of 21 cases. In one specimen, where an inverted papilloma associated with a squamous cell carcinoma was histologically confirmed, HPV18-specific primers detected the HPV18 genome. The tumors in which an amplification of HPV DNA fragments were observed showed the highest proliferation scores along with the highest rate of aneuploid cells detected by quantitative DNA analysis.

p53 protein expression in benign lesions of the upper respiratory tract

OBJECTIVE

p53 is a tumor suppressor gene that is lost or mutated in most forms of human malignancy. There are, however, very few studies evaluating p53 expression in normal epithelium or benign lesions.

DESIGN

We screened for p53 protein expression in a variety of benign epithelial lesions of upper respiratory tract using monoclonal antibody DO-1 on paraffin-embedded material.

SUBJECTS

We studied a total of 109 cases: 16 cases of juvenile and 36 cases of adult laryngeal papillomatosis, 10 cases each of laryngeal nodules and laryngeal polyps, 17 cases of inverted papilloma, and 20 cases of nasal polyps.

RESULTS

Nuclear immunoreactivity for p53 protein was demonstrated in 14 (88%) of 16 cases of juvenile laryngeal papillomatosis, 33 (92%) of 36 cases of adult laryngeal papillomatosis, 4 (40%) of 10 cases of laryngeal nodules, 8 (80%) of 10 cases of laryngeal polyps, 7 (41%) of 17 cases of inverted papilloma, and 2 (10%) of 20 cases of nasal polyps. These results pertained only to the basal epithelial layer in all cases of laryngeal nodules, laryngeal polyps, and nasal polyps. Intermediate layer cells were also positive for p53 in the majority of the cases of both juvenile (69%) and adult (75%) laryngeal papillomatosis and in a minority of the cases of inverted papilloma (18%).

CONCLUSIONS

Overexpression of p53 protein is commonly demonstrable in benign epithelial lesions of the upper respiratory tract. This observation suggests that p53 protein accumulation may occur in the absence of mutation of the p53 gene and may correlate with epithelial proliferative activity.

Inverted ductal papilloma of minor salivary gland origin: morphological aspects and cytokeratin expression

Ultrastructural features and cytokeratin expression of inverted ductal papillomas of minor salivary gland origin were studied. Under the electron microscope, an increased number of desmosomes and mucus-like granules in some cells were the most striking features. Immunohistochemical study revealed that tumor cells displayed strongly positive reactions with cytokeratins 13 and 14, and less strong reactions with cytokeratins 7, 8, 18 and 5D3. These results support the hypothesis that an inverted ductal papilloma can be derived from the proximal portion of a salivary gland excretory duct.

A majority of inverted sinonasal papillomas carries Epstein-Barr virus genomes

BACKGROUND

The relationship between sinonasal inverted papilloma (IP) and various strains of human papilloma virus (HPV) has been examined previously. Yet there is little consensus regarding the incidence or role of HPV in IP. The possible role of Epstein-Barr virus (EBV), which, like HPV, is a DNA virus linked to human lymphoid and epithelial malignancies, was investigated.

METHODS

The polymerase chain reaction (PCR) was used to detect EBV genomic sequences in surgical specimens of IP, in benign nasal polyps, and various control tissues. The IP specimens were similarly examined for the presence of HPV types 6, 11, 16, and 18.

RESULTS

EBV DNA was found in 13 of 20 IP specimens (65%) and none of the 10 control tissues. Nine of the 20 specimens contained HPV DNA, and 5 of 20 specimens contained both EBV and HPV.

CONCLUSIONS

These results imply a previously unsuspected role for Epstein-Barr virus in the pathogenesis of sinonasal inverted papilloma.

Human papillomavirus (HPV) in sinonasal papillomas: a study of 78 cases using in situ hybridization and polymerase chain reaction

To determine the role of human papillomavirus (HPV) in the etiology of sinonasal papillomas, 57 inverted papillomas including 5 cases associated with carcinomas, 16 exophytic papillomas, and 5 cases of columnar cell papillomas were examined for the presence of HPV DNA by in situ hybridization and polymerase chain reaction (PCR). The genetic studies were performed on the formalin-fixed, paraffin-embedded material. In only 6% of the 52 benign inverted papillomas was HPV DNA identified, whereas 69% of the exophytic papillomas were infected by HPV DNA. In none of the 5 cases with columnar cell papillomas could HPV be demonstrated. HPV 6/11 was identified in all of these HPV-positive cases. In the carcinoma area, HPV was detected in 2 (1 HPV 6/11 and 1 HPV 18) of the 5 inverted papillomas associated with carcinomas. The findings confirm the presence of HPV DNA in sinonasal papillomas. The results also indicate that HPV 6/11 may be involved in the pathogenesis of, solely, exophytic papillomas. We found that in situ hybridization and PCR seem equally sensitive in detecting HPV in sinonasal papillomas.

[Inverted papilloma and its association with human papillomavirus (HPV). A study with polymerase chain reaction (PCR)]

Nasal inverted papilloma is usually a benign tumor but is associated with squamous cell carcinoma in about 10% of cases. To determine the etiological role of human papillomavirus (HPV) in inverted papilloma and to clarify the relationship between the different types of human papillomavirus and malignant transformation, we analyzed retrospectively a series of 29 formalin - fixed, paraffin-embedded cases, 3 of which had squamous cell carcinoma. A highly sensitive and specific modification of the polymerase chain reaction (PCR) was used to detect the E6 gene sequences of HPV 6/11, 16 and 18. HPV was present in 20 of the cases (69%), HPV 6/11 in 14 (48%), HPV 16 in 19 (65%) and both HPV 6/11 and 16 in 13 of the specimens (45%). HPV 18 was not identified in any specimen. In all three of the squamous cell carcinomas based on inverted papillomas, HPV 6/11 and 16 were detected. These results were in agreement with other studies. While HPV is related etiologically to inverted papilloma, we suggest that HPV 16 may be involved in its malignant transformation.

Nuclear deoxyribonucleic acid content in inverted papilloma of the urothelium

We analyzed formalin-fixed and paraffin-embedded materials from urothelial inverted papillomas using flow-cytometric DNA analysis to investigate the intrinsic nature in terms of the malignant potentials. DNA indices of the inverted papillomas ranged between 1.00 and 1.26 with a mean value of 1.12. The percentage of S phase of a tumor DNA histogram showed greater values in every case compared with a normal DNA histogram. This tumor form could be thus regarded as a diploid neoplastic disease with a relatively higher proliferative activity, although 1 case showed an aneuploid pattern (DNA index = 1.26), in which bladder carcinoma developed subsequently.

A case of inverted papilloma of the ureter: is the DNA ploidy pattern associated with occurrence of transitional cell carcinoma of the bladder?

We describe herein a case of inverted papilloma of the ureter, in which transitional cell carcinoma of the bladder developed twenty-three months after nephroureterectomy. Flow cytometric analysis of formalin-fixed and paraffin-embedded archival material of the inverted papilloma revealed DNA aneuploidy pattern and relatively high percentage of S phase. Retrospectively, DNA measurement thus provided the predictive value regarding biological activity and the clinical behaviour of the present case.