The differential effects of mutant p53 alleles on advanced murine lung cancer

We report a direct comparison of the differential effects of individual p53 mutations on lung tumor growth and progression, and the creation of a murine model of spontaneous advanced lung adenocarcinoma that closely recapitulates several aspects of advanced human pulmonary adenocarcinoma. We generated compound conditional knock-in mice with mutations in K-ras combined with one of three p53 alleles: a contact mutant, a structural mutant, or a null allele. p53 loss strongly promoted the progression of K-ras-induced lung adenocarcinomas, yielding a mouse model that is strikingly reminiscent of advanced human lung adenocarcinoma. The influence of p53 loss on malignant progression was observed as early as 6 weeks after tumor initiation. Furthermore, we found that the contact mutant p53R270H, but not the structural mutant p53R172H, acted in a partially dominant-negative fashion to promote K-ras-initiated lung adenocarcinomas. However, for both mutants, loss-of-heterozygosity occurred uniformly in advanced tumors, highlighting a residual tumor-suppressive function conferred by the remaining wild-type allele of p53. Finally, a subset of mice also developed sinonasal adenocarcinomas. In contrast to the lung tumors, expression of the point-mutant p53 alleles strongly promoted the development of sinonasal adenocarcinomas compared with simple loss-of-function, suggesting a tissue-specific gain-of-function.

Classes of c-KIT activating mutations: proposed mechanisms of action and implications for disease classification and therapy

Mutations causing constitutive activation of KIT have been shown to be causative in some forms of mastocytosis, and several types of mutations have been associated with myeloproliferative disorders (MPDs), acute myelogenous leukemia (AML), sinonasal lymphomas, and gastrointestinal stromal tumors (GIST). We divide these activating mutation into two types - 'regulatory type' mutations, which affect regulation of the kinase molecule, and 'enzymatic pocket type' mutations, which alter the amino acid sequence directly forming the enzymatic site. KIT inhibitors have been suggested as therapeutic drugs for these conditions, but different types of activating mutations respond differentially to KIT inhibitors, so classification of individuals on the basis of specific mutations is necessary to guide therapy.

Genome sequencing of mucosal melanomas reveals that they are driven by distinct mechanisms from cutaneous melanoma

Mucosal melanoma displays distinct clinical and epidemiological features compared to cutaneous melanoma. Here we used whole genome and whole exome sequencing to characterize the somatic alterations and mutation spectra in the genomes of ten mucosal melanomas. We observed somatic mutation rates that are considerably lower than occur in sun-exposed cutaneous melanoma, but comparable to the rates seen in cancers not associated with exposure to known mutagens. In particular, the mutation signatures are not indicative of ultraviolet light- or tobacco smoke-induced DNA damage. Genes previously reported as mutated in other cancers were also mutated in mucosal melanoma. Notably, there were substantially more copy number and structural variations in mucosal melanoma than have been reported in cutaneous melanoma. Thus, mucosal and cutaneous melanomas are distinct diseases with discrete genetic features. Our data suggest that different mechanisms underlie the genesis of these diseases and that structural variations play a more important role in mucosal than in cutaneous melanomagenesis.

HPV-related Multiphenotypic Sinonasal Carcinoma: An Expanded Series of 49 Cases of the Tumor Formerly Known as HPV-related Carcinoma With Adenoid Cystic Carcinoma-like Features

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC), originally known as HPV-related carcinoma with adenoid cystic carcinoma-like features, is a peculiar neoplasm that is restricted to the sinonasal tract, exhibits features of both a surface-derived and salivary gland carcinoma (particularly adenoid cystic carcinoma), and is associated with high-risk HPV. Given the limited number of published cases, the full clinicopathologic spectrum of this neoplasm is unclear. Here, we present an updated experience of 49 cases. All cases of HMSC were obtained from the authors' files. Immunohistochemistry for p16, c-kit, and myoepithelial cell markers (S100, actin, calponin, p63, and/or p40) was performed along with RNA in situ hybridization for HPV (type 33-specific as well as a high-risk cocktail). Fluorescence in situ hybridization studies for fusions of MYB, NFIB, and MYBL1 was performed on a subset of cases. Clinical follow-up was obtained from medical records. A total of 49 cases of HMSC were collected. Twenty-eight (57%) were from women and 18 (43%) from men, ranging in age from 28 to 90 years (mean, 54 y). Of 40 cases with detailed staging information, 43% of HMSCs presented with a high T-stage (T3 or T4). Histologically, most grew predominantly as solid nests of basaloid cells exhibiting high mitotic rates and frequent necrosis, with histologic and immunohistochemical evidence of myoepithelial differentiation. Most cases also demonstrated foci of cribriform and/or tubular growth, along with an inconspicuous population of ducts. Thirty-four (69%) cases demonstrated an unusual pattern of surface involvement where markedly atypical squamous cells colonized tracts of the sinonasal mucosa. Less consistent histologic features included squamous differentiation within the invasive tumor (n=6), sarcomatoid transformation (n=5) including overt chondroid differentiation (n=3), and prominent epithelial-myoepithelial carcinoma-like growth (n=3). All cases were positive for p16 by immunostaining and HPV by RNA in situ hybridization. Thirty-three (67%) were positive for HPV 33. No cases tested for MYB, MYBL1, or NFIB gene fusions were positive. In the 38 cases with follow-up data, (mean follow-up, 42 mo) 14 recurred locally and 2 metastasized (lung, finger). There were no regional lymph node metastases, and no tumor-related deaths. HMSC is a distinct sinonasal neoplasm characterized by myoepithelial differentiation, frequent surface epithelial involvement, and the presence of high-risk HPV (especially type 33). Although it classically exhibits a cribriforming pattern that closely resembles adenoid cystic carcinoma, our expanded series highlights a histologic spectrum that is much broader than previously recognized, warranting a change in terminology. HMSC usually presents as a large and destructive sinonasal mass with high-grade histologic features, but it paradoxically behaves in a relatively indolent manner, underscoring the importance of distinguishing HMSC from true adenoid cystic carcinoma, squamous cell carcinoma, and other histologic mimickers.

Prediction of TP53 status for primary cisplatin, fluorouracil, and leucovorin chemotherapy in ethmoid sinus intestinal-type adenocarcinoma

PURPOSE

To assess the role of TP53 status in predicting pathologic complete remission after primary chemotherapy in patients with ethmoidal intestinal-type adenocarcinoma (ITAC).

PATIENTS AND METHODS

Thirty patients with ethmoidal ITAC enrolled onto a phase II study received chemotherapy with cisplatin, fluorouracil, and leucovorin (PFL) followed by surgery and radiation. On surgical specimens, absence of viable tumor cells was defined as pathologic complete remission (pCR). TP53 status/p53 function, analyzed on pretreatment biopsies, were retrospectively correlated with pathologic results and patient outcome.

RESULTS

Twelve patients achieved a pCR; 18 patients did not (overall response rate, 40%). In patients with wild-type (wt) TP53 or functional p53 protein, the pCRs were 83% and 80%, respectively; in patients with mutated TP53 or impaired p53 protein, pCRs were 11% and 0%, respectively (P < or = .0001). At a median 55-month follow-up, all pCR patients were disease-free; 44% of nonresponding patients experienced relapse (P = .0061).

CONCLUSION

The results indicate the existence of two genetic ITAC subgroups, defined by differences in TP53 mutational status or protein functionality, that strongly influence pathologic response to primary chemotherapy and, ultimately, prognosis. PFL seems to be highly effective in terms of pCR and disease-free survival in the presence of a wt or a still-efficient p53 protein, even when encoded by a mutated TP53 gene (eg, early-stop codon mutation), but ineffective in ITACs carrying a disabled p53 protein. Whether this model is extensible to other head and neck cancers needs appropriate investigation.

Sinonasal Adenocarcinoma: Update on Classification, Immunophenotype and Molecular Features

Adenocarcinomas of the sinonasal tract may originate from respiratory surface epithelium or the underlying seromucinous glands. These malignancies are divided into salivary-type adenocarcinomas and non-salivary-type adenocarcinomas. The latter are further divided into intestinal-type and nonintestinal-type adenocarcinomas. This review provides an update on tumor classification, differential diagnostic considerations and molecular features, as well as new adenocarcinoma entities in the sinonasal area.

TP53, p14ARF, p16INK4a and H-ras gene molecular analysis in intestinal-type adenocarcinoma of the nasal cavity and paranasal sinuses

Intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinuses is an uncommon tumor associated with occupational exposure to dusts of different origin. Few investigations addressed molecular alterations in ITAC mainly focused on TP53, K-ras and H-ras gene mutations. The occurrence of TP53, p14(ARF) and p16(INK4a) deregulation and H-ras mutations was investigated in 21 consecutive and untreated ITACs cases, 17 with known professional exposure. No H-ras mutations were found. In patients with known exposure, cumulative evidence of TP53 or p14(ARF) alterations accounted for 88% and the evidence of p16(INK4a) alterations for 65%, respectively. TP53 mutations were present in 44% of the ITACs, consisted of G:C-->A:T transitions in 86%, and involved the CpG dinucleotides in 50% of the cases. LOH at the locus 17p13 and an uncommon high rate of p53 stabilization were detected in 58% and 59% of the cases, respectively. p14(ARF)and p16(INK4a) promoter methylation accounted for 80% and 67% respectively, and LOH at the locus 9p21 occurred in 45% of the cases. Interestingly, all dust-exposed tumors with p16(INK4a) alterations shared TP53 or p14(ARF) deregulation. The present results show a close association of this occupational tumor with TP53, p14(ARF) and p16(INK4a) gene deregulation. Given the important role that these genes play in cell growth control and apoptosis, the knowledge of ITAC genetic profile may be helpful in selecting more tailored treatments.

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.

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.

Genetic analysis of sinonasal adenocarcinoma phenotypes: distinct alterations of histogenetic significance

Sinonasal adenocarcinomas, a relatively rare entity, are composed of distinctly different morphologic subtypes with variable biological behavior. To investigate the genetic events associated with their development and clinicopathologic features, we analyzed the alterations in K-ras, APC, beta-catenin, hMLH1 and hMSH2 and p53 genes expression in a cohort of 15 primary tumors comprising the two main sinonasal adenocarcinoma subtypes (enteric and seromucinous). The patients consisted of 13 men and two women, who ranged in age from 50 to 87 years. Tumors were predominantly located in the ethmoid sinus. Eight tumors were Enteric-type, and seven were seromucinous type. Nine patients were smokers and four were nonsmokers; and no information was available on two patients. Two of the eight enteric-type, had K-ras mutation at codons 12A and 12B, and one showed microsatellite instability at BAT-25. Two patients with enteric-type tumors had a history of wood-dust exposure, and one had a K-ras mutation at 12A codon as well as p53 overexpression. No patients with the seromucinous type had any genetic abnormalities, except for overexpression of p53 in two tumors. Our results show that (1) a subset of enteric-type sinonasal adenocarcinoma shares certain genetic alterations with colonic adenocarcinomas, (2) the seromucinous-type sinonasal adenocarcinoma lacks alterations and may develop through a different pathway, (3) high p53 expression is associated with aggressive tumor features in both subtypes and (4) the enteric-type runs a more malignant course than the seromucinous counterpart.

ETV6 Gene Rearrangements Characterize a Morphologically Distinct Subset of Sinonasal Low-grade Non-intestinal-type Adenocarcinoma: A Novel Translocation-associated Carcinoma Restricted to the Sinonasal Tract

Low-grade sinonasal adenocarcinomas (low-grade SNACs) of the sinonasal tract comprise a poorly characterized and histologically heterogeneous group of tumors. We describe three cases of a histologically distinct variant of low-grade SNAC characterized by ETV6 gene rearrangements. The patients included 2 women (aged 32 and 88 y) and a man (aged 75 y); all were initially treated with surgery alone. Follow-up ranged from 9 to 170 months with one patient having 2 local recurrences and none experiencing distant or regional metastases. Tumors were composed of cytologically bland columnar and cuboidal eosinophilic tumor cells with basally located nuclei arranged in tubular and tubulotrabecular patterns. Immunohistochemically, CK7, DOG1, GCDFP-15, and SOX10 were positive in all cases, and vimentin was positive in 2 cases. Scattered single cells or small groups of tumor cells were S-100 positive. Only one case had weak, focal expression of GATA3, and mammaglobin was consistently negative. Two cases had ETV6-NTRK3 gene fusions, whereas ETV6 had an unknown fusion partner gene in one case. The highly similar morphology, immunohistochemical profile, and genetics of the presented cases are suggestive of a specific disease. Although translocation-associated adenocarcinomas in the sinonasal tract have previously been described exclusively as salivary-type carcinomas, we present the first type of carcinoma characterized by recurrent genetic rearrangements and distinct phenotype occurring exclusively in the sinonasal tract with no known major salivary gland counterpart. We provisionally designate this tumor ETV6-rearranged low-grade SNAC. Identification of additional cases is necessary to fully appreciate the morphologic and biological spectrum of this disease.

DEK-AFF2 Carcinoma of the Sinonasal Region and Skull Base: Detailed Clinicopathologic Characterization of a Distinctive Entity

A novel DEK-AFF2 fusion was recently reported in 4 nonkeratinizing squamous cell carcinomas of the sinonasal region and skull base, including 1 with exceptional response to immunotherapy, but it is not yet clear if this rearrangement defines a unique clinicopathologic category or represents a rare event. This study aims to characterize a larger cohort of carcinomas with DEK-AFF2 fusions to assess whether they truly constitute a distinctive entity. Among 27 sinonasal and skull base nonkeratinizing squamous cell carcinoma that were negative for human papillomavirus and Epstein-Barr virus, RNA sequencing identified DEK-AFF2 fusions in 13 cases (48%). Nine were centered in the nasal cavity, 2 in the middle ear/temporal bone, 1 in the nasopharynx, and 1 in the orbit. These tumors displayed recurrent histologic features including (1) complex endophytic and exophytic, frequently papilloma-like growth, (2) transitional epithelium with eosinophilic to amphophilic cytoplasm, (3) absent or minimal keratinization with occasional compact keratin pearls, (4) monotonous nuclei, and (5) prominent tumor-infiltrating neutrophils or stromal lymphocytes. This appearance not only overlaps with high-grade basaloid sinonasal carcinomas but also with benign papillomas and tumors reported as low-grade papillary Schneiderian carcinoma. However, DEK-AFF2 carcinomas showed frequent local recurrence, cervical lymph node metastases, and distant metastasis with 2 deaths from disease, confirming they are aggressive malignancies despite relatively bland histology. Overall, the distinctive molecular, histologic, and clinical features of DEK-AFF2 carcinomas suggest they represent a unique entity in the sinonasal region. This tumor merits increased pathologic recognition to better understand its prognostic and therapeutic implications.

K-ras mutations in sinonasal adenocarcinomas in patients occupationally exposed to wood or leather dust

Of 39 males diagnosed with sinonasal adenocarcinomas over 30 years in the Lund University Hospital catchment area (1.5 million inhabitants), archival tumor tissue was available from 29. Of these, 16 had been exposed to wood dust and three had been exposed to leather dust. The intestinal-type and papillary adenocarcinomas were more common in the exposed patients (P = 0.0002, Fisher's exact test). The tumors from all but one of the 29 sinonasal adenocarcinomas could be analyzed for point mutations at codons 12, 13 and 61 of the K-ras gene. Four mutations were detected in the 28 tumors. The three mutations in the patients exposed to wood and leather dust were all G:C --> A:T transitions, with two at position 2 of codon 12 and one at position 2 of codon 13. The high proportion of G:C --> A:T mutations in this rare tumor may reflect a genotoxic agent in wood and leather dust.

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.

Comparative genomic hybridization in primary sinonasal adenocarcinomas

BACKGROUND

Little is known about the genetic alterations that occur in sinonasal adenocarcinomas. The goal of the current study was to detect recurrent chromosomal gains and losses in a series of 21 primary sinonasal adenocarcinomas using comparative genomic hybridization (CGH).

METHODS

The authors examined ethmoid sinus adenocarcinoma samples from 21 patients. All 21 adenocarcinomas were associated with work-related exposure to wood dust. CGH was used to detect chromosomal abnormalities, and the results of CGH analysis were evaluated for correlations with clinicopathologic characteristics.

RESULTS

Chromosomal gains and losses were detected in all 21 adenocarcinomas. Gains were detected at high frequencies at 7q11-21 (n = 15 [71%]), 18p11 (n = 14 [66%]), 8q11-22 (n = 13 [62%]), 5p11-13 (n = 12 [57%]), 12q11-13 and 19p (n = 11 [52%]), 20q (n = 10 [47%]), X and 5p (n = 9 [43%]), and 3q26-27 (n = 8 [38%]); and losses were detected at 8p22-23 (n = 18 [86%]), 18q22-23 (n = 17 [80%]), 17p13 (n = 12 [57%]), and 5q31-qter (n = 11 [52%]). Aside from low-level gains, 43 high-level amplifications were observed in the current series of 21 tumors, most commonly at Xq13 (n = 7 [33%]).

CONCLUSIONS

CGH revealed that ethmoid sinus adenocarcinomas carry a large number of chromosomal losses and gains, including high-level amplifications. To the authors' knowledge, the current study represents the first attempt to investigate sinonasal adenocarcinomas on a genetic level by using CGH. The pattern of chromosomal abnormalities in these tumors was different from the pattern in other tumors within the same anatomic region (e.g., squamous cell carcinomas and salivary gland tumors); this finding may be explained by differences in etiology. Nonetheless, sinonasal adenocarcinomas appear to be genetically similar to adenocarcinomas of the stomach and colon, which also have an etiology that differs from that of sinonasal adenocarcinomas. Further study is necessary to better understand the molecular genetic basis underlying the development of sinonasal adenocarcinomas. In the near future, this type of understanding may present new possibilities for prevention and treatment of malignant disease.

Oncogene abnormalities in a series of primary melanomas of the sinonasal tract: NRAS mutations and cyclin D1 amplification are more frequent than KIT or BRAF mutations

Primary malignant melanoma of sinonasal tract is a rare but severe form of melanoma. We retrospectively analyzed 17 cases and focused on the histologic presentation and the expression of c-Kit, epidermal growth factor receptor (EGFR), cyclin D1/Bcl-1, PS100, and HMB45 and searched for BRAF, NRAS, and KIT mutations that are known to be associated with melanoma subtypes, together with amplifications of KIT, cyclin D1, cyclin-dependent kinase 4, MDM2, and microphthalmia-associated transcription factor using quantitative polymerase chain reaction. In most cases (78%), an in situ component was evidenced. Invasive components were composed of diffuse areas of rhabdoid, epithelioid, or spindle cells and, in most cases, lacked inflammatory reaction, suggesting that an immune escape phenomenon probably develops when the disease progresses. EGFR was rarely and weakly expressed in the in situ component of 2 cases. None of the investigated case showed BRAF V600E, but 1 had a D594G mutation. NRAS mutations in exon 2 (G12D or G12A) were found in 3 cases (18%), and a KIT mutation in exon 11 (L576P), in 1, whereas c-Kit was expressed at the protein level in half of the cases. Amplifications of cyclin D1 were evidenced in 5 cases, confirmed in 3 by fluorescence in situ hybridization, but this was not always correlated with protein expression, found in 8 patients (62.5%), 3 having no significant amplification. In conclusion, primary malignant melanoma of sinonasal tract is not associated with BRAF V600E mutations. Instead, NRAS or KIT mutations and cyclin D1 amplification can be found in a proportion of cases, suggesting that primary malignant melanoma of sinonasal tract is heterogeneous at the molecular level and should not be sensitive to therapeutic approaches aiming at BRAF.

Tumor Suppressor Gene Alterations in Respiratory Epithelial Adenomatoid Hamartoma (REAH)

Respiratory epithelial adenomatoid hamartoma (REAH) is an unusual benign sinonasal glandular proliferation. REAH is not considered a neoplasm, although, no molecular evidence exists to support or refute this possibility. Microdissection of 10 cases of REAH, 9 cases of sinonasal adenocarcinoma (SNAC) and 10 cases of chronic sinusitis was performed. DNA was extracted and polymerase chain reaction performed using fluorescently labeled primers flanking known tumor suppressor genes on chromosomes 9p (CDKN2/p16), 11p (H-ras), 17p (p53), and 18q (DCC/DPC4). Polymerase chain reaction products were analyzed semiquantitatively by capillary electrophoresis. Allele ratios were calculated using the peak height from the shorter allele divided by the peak height from the longer allele. The loss of heterozygosity (LOH) ratio was calculated as the allele ratio from tumor tissue divided by the allele ratio from normal tissue. The fractional allelic loss (FAL) was calculated as the percentage of loci that harbored LOH divided by the number of loci that were informative. REAH demonstrated an intermediate FAL of 31% compared with SNAC (64%) and chronic sinusitis (2%). REAH and SNAC had the highest LOH for multiple loci located on 9p (p16) and 18q (DCC/DPC4). The molecular profile of REAH shows a mean FAL of 31%, which would be considered unusually high for a non-neoplastic entity. Appreciable allelic loss within REAH suggests the possibility that REAH may be a benign neoplasm rather than a hamartoma.

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).

Distinct chromosomal aberrations in sinonasal mucosal melanoma as detected by comparative genomic hybridization

Sinonasal mucosal melanomas are the most frequent mucosal melanomas and arise from melanocytes located in the nasal cavity and the paranasal sinuses. The melanoma types, cutaneous melanoma, uveal melanoma, and mucosal melanoma, differ in etiology, geographic distribution, and clinical behavior. Genetic alterations have been previously studied in cutaneous and uveal melanomas but, to the best of our knowledge, not in mucosal melanomas. Comparative genomic hybridization (CGH) was performed on 14 routinely processed sinonasal mucosal melanomas. Furthermore, ploidy analysis was performed on 11 tumors to provide complementary data on the DNA index. The CGH profiles of sinonasal mucosal melanomas show remarkably consistent alterations: chromosome arm 1q is gained in all tumors and gains of 6p and 8q are present in 93 and 57%, respectively. Comparison of CGH data with both the common variants of cutaneous melanoma and uveal melanoma revealed that sinonasal mucosal melanomas harbor a distinct pattern of chromosomal abnormalities. Ploidy analysis also showed that diploid tumors exhibit gains of 1q and alterations of chromosome 6 (3 of 3 cases tested), whereas clear-copy gains and high-copy gains were seen only in triploid and tetraploid tumors (6 of 8 cases tested). This indicates that alteration of chromosomes 1 and 6 may precede polyploidization and formation of clear-copy gains and high-copy gains.

Sinonasal hemangiopericytomas. A clinicopathologic and DNA content study

The clinicopathologic and the flow cytometric DNA characteristics of 14 patients with sinonasal hemangiopericytomas are presented. Patient and tumor characteristics were similar to previously published series. Flow cytometric analysis revealed a diploid DNA pattern and low S-phase in 13 neoplasmas and an aneuploid DNA pattern with relatively high S-phase in one. Histopathologically, all diploid and low S-phase neoplasms displayed relatively uniform cellular features and low mitotic counts. All patients are alive and free of disease; one is still alive after a single recurrence. Our data suggest that sinonasal hemangiopericytomas are low-grade neoplasms as evidenced by their histomorphology and their DNA content. Recurrences are delayed and can be controlled.

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.

Sinonasal desmoplastic small round cell tumor: a case report

A case of sinonasal desmoplastic small round cell tumor in a 21-year-old woman is presented. The tumor possessed the diagnostic histologic, immunohistochemical, and genetic characteristics of desmoplastic small round cell tumor. Histologically, the tumor was composed of nests of tumor cells surrounded by a desmoplastic stroma. Immunohistochemical staining was positive for keratin, vimentin, desmin, and, focally, neuron-specific enolase. The desmin immunopositivity was of a classic dot-like perinuclear pattern. RT-PCR analysis showed the fusion transcript resulting from the t(11;22)(p13;q12) reciprocal translocation. This case of sinonasal desmoplastic small round cell tumor, the third reported case not associated with a serosal surface, further obscures the nature and histogenesis of this entity.

Chromosomal imbalances in wood dust-related adenocarcinomas of the inner nose and their associations with pathological parameters

Comparative genomic hybridization (CGH) was used to screen 42 wood dust-related sinonasal adenocarcinomas for chromosomal alterations. The tumour collection comprised 39 papillary-tubular cylinder cell adenocarcinomas (PTCCs; six cases G1, 23 G2, and ten G3), two alveolar goblet cell adenocarcinomas (AGCs), and one signet ring cell adenocarcinoma (SRC), according to the Kleinsasser and Schroeder classification. Copy number changes were detected in 41 tumours (97.6%). The one carcinoma without imbalances was a PTCC-G1. DNA gains were most frequently seen on chromosomes 12p (83%), 7q (74%), 8q (71%), and 20q (71%), 11q (61%), 22 (59%), and 1q (52%). Pronounced overrepresentations suggestive of high copy amplifications were detected on 8q (15 cases, 36%), 7q (six cases, 14%), 20q (five cases, 12%), 13q14 (three cases, 7%), 1q22, 5p, 12p and 20 (two cases, 5% each), and 2q24, 3q13, 3q22, 7p, 14q12, and 16q13 (one case, each 2%). Frequent chromosomal losses occurred at 5q (81%), 18q (76%), 4 (74%), 8p (61%), 9p (60%), 6q and 17p (52% each), and 3p, 13q, and 21 (50% each). There was a quantitative as well as a qualitative increase of alterations from PTCC-G1 to PTCC-G2 and finally PTCC-G3, confirming the usefulness of histopathological grading. While PTCC-G1 carried only a few alterations, namely gains on chromosomes 17 and 7 as well as losses of 4q and 13q, PTCC-G2 already carried many of the above-mentioned alterations, while PTCC-G3 showed significantly more gains of 7q, 8q, and 12p, and losses of 8p and 17p. Additionally, the latter subgroup was particularly prone to carry pronounced DNA gains. These data provide further evidence for a recurrent pattern of chromosomal imbalances in sinonasal adenocarcinomas and highlight distinct aberrations that are associated with tumour differentiation and progression.

Analysis of p53, K-ras, c-kit, and beta-catenin gene mutations in sinonasal NK/T cell lymphoma in northeast district of China

Recently we reported the different frequencies of p53 and c-kit gene mutations among sinonasal NK/T cell lymphoma (NKTCL) in Korea, north China (Beijing), and Japan, suggesting some racial, environmental, or life-style differences as a possible cause of nasal tumorigenesis. In this study, gene mutations in p53, c-kit, K-ras, and beta-catenin gene were analyzed by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) followed by direct sequencing in 20 cases of sinonasal NKTCL from northeast China (Shen Yang). Age of patients ranged from 5 to 63 (median, 40.0) years. p53 gene mutations were found in eight of 20 cases (40%), with exon 4 involvement in 10% of cases. The majority was missense mutations and G:C to A:T transition was predominant. The frequency of the c-kit and K-ras gene mutations was low (5%), while that of the beta-catenin gene was six of 20 cases (30%). From these findings, it is concluded that nasal NKTCL in northeast China shared common features with that in Korea in the younger onset of disease compared to that in Japan and lower frequency of p53 gene mutations with infrequent exon 4 involvement compared to that in Japan and north China. These differences might be caused by migration of susceptible populations or some environmental confounding factors.

Familial frontonasal dermoid cysts. Report of four cases

✓ A family group, comprised of father and all three children, had frontonasal dermoid cysts. Clinical features and x-ray findings are discussed, and the similarity to a slow-growing intracranial space-occupying lesion is emphasized. Plain x-ray films may show a widened nasal septum, and contrast radiology will help outline an avascular mass arising from the cribriform plate. Resection utilizing a synchronous nasal and frontal operation proved effective.