[ALK-positive anaplastic large cell lymphoma of paranasal sinuses: two cases report and literature review]. / ALK-pozitivnaya anaplasticheskaya krupnokletochnaya limfoma s porazheniem pridatochnykh pazukh nosa: dva klinicheskikh nablyudeniya i obzor literatury.

ALK-positive anaplastic large cell lymphoma is a rare T-cell lymphoma with ALK gene rearrangement that develops in children and young adults. The disease almost always affects the lymph nodes, and extranodal areas are also frequently involved. This article describes two cases of atypical localization of ALK-positive anaplastic large cell lymphoma with involvement of the paranasal sinuses.

Unusual PEComa With PRCC :: TFE3 Fusion Mimicking Sinonasal Tract Melanoma.

BACKGROUND: We report a nasal cavity unusual perivascular epithelioid cell tumor (PEComa) mimicking mucosal melanoma. METHODS: Immunohistochemistry was performed using BenchMark Ultra and panel of antibodies. The Ion Torrent platform and Ion AmpliSeq cancer hotspot panel were utilized for DNA genotyping. Target-specific RNA libraries for the detection of fusion transcripts were constructed using Archer Universal RNA Reagent Kit v2 and Archer FusionPlex Solid Tumor panel and sequenced on the MiSeqDx instrument. RESULTS: The tumor, diagnosed in 46-year-old female, was composed of spindle cells, and lacked pigmentation. Immunohistochemically, it showed a patchy HMB-45 positivity. Other melanocytic markers (S100 protein, Melan-A, SOX10) were negative. The tumor cells were weakly positive for KIT (CD117) while negative for smooth muscle actin, pancytokeratin cocktail (AE1/AE3), and synaptophysin. Diagnosis of primary sinonasal tract mucosal melanoma was favored. Additional molecular studies detected PRCC :: TFE3 fusion as the sole genetic change, and suggested the diagnosis of unusual PEComa. Previously, TFE3 fusions were reported in a subset of PEComas but not in melanomas, while PRCC involvement has only been documented once in an ocular PEComa. Immunohistochemistry revealed strong nuclear TFE3 expression concordant with the molecular findings. CONCLUSIONS: This report emphasis the importance of molecular testing in the differential diagnosis between PEComa and melanoma, especially when the tumor arises in a site typical of melanoma but showing an unusual morphology and immunophenotype. The detection of TFE3 fusion transcripts suggested the diagnosis of SNT PEComa, although it cannot be excluded that this and similar tumors represent a distinct diagnostic category.

Expression of immune checkpoint molecules TIGIT and TIM-3 by tumor-infiltrating lymphocytes predicts poor outcome in sinonasal mucosal melanoma.

BACKGROUND: Sinonasal mucosal melanoma (SNMM) is a rare but aggressive tumor with a poor prognosis. The co-inhibitory receptors T cell immunoglobulin and mucinodomain containing-3 (TIM-3), lymphocyte activation gene-3 (LAG-3) and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) are promising new targets in anti-cancer immunotherapy. The expression profiles of these immune checkpoint molecules (ICMs) and potential prognostic implications have not been characterized in SNMM yet. METHODS: Immunohistochemical staining for TIGIT, LAG-3 and TIM-3 was performed on tumor tissue samples from 27 patients with primary SNMM. Associations between ICM expression and demographic parameters, AJCC tumor stage, overall survival, and recurrence-free survival were retrospectively analyzed. RESULTS: SNMM patients with low numbers of TIGIT+ and TIM-3+ tumor infiltrating lymphocytes (TILs) in the primary tumor survived significantly longer than patients with a high degree of TIGIT+ and TIM-3+ TILs. High infiltration with TIM-3+ or TIGIT+ lymphocytes was associated with the higher T4 stage and decreased 5-year survival. CONCLUSION: We identified high densities of TIM-3+ and TIGIT+ TILs as strong negative prognostic biomarkers in SNMM. This suggests that TIM-3 and TIGIT contribute to immunosuppression in SNMM and provides a rationale for novel treatment strategies based on this next generation of immune checkpoint inhibitors. Prospective studies with larger case numbers are warranted to confirm our findings and their implications for immunotherapy.

Assessment of TP53 and CDKN2A status as predictive markers of malignant transformation of sinonasal inverted papilloma.

The mechanism and predictive biomarkers of sinonasal inverted papilloma (IP) transformation into squamous cell carcinoma (SCC) are still unclear. We investigated the genetic mutations involved and the predictive biomarkers. Fourteen patients with SCC arising from IP and six patients with IPs without malignant transformation (sIP) were included. DNA was extracted separately from areas of normal tissue, IP, dysplasia, and SCC. Whole exome sequencing and immunohistochemistry was performed. Major oncogenic mutations were observed in the progression from IP to SCC. The most frequently mutated genes were TP53 (39%) and CDKN2A (27%). Mutations in TP53 and/or CDKN2A were observed in three of six IPs with malignant transformation (cIP); none were observed in sIPs. Tumor mutational burden (TMB) increased from IP to SCC (0.64/Mb, 1.11/Mb, and 1.25 for IP, dysplasia, and SCC, respectively). TMB was higher in the cIPs than in the sIPs (0.64/Mb vs 0.3/Mb). Three cIPs showed a diffuse strong or null pattern in p53, and one showed a total loss of p16, a distinct pattern from sIPs. Our result suggests that TP53 and CDKN2A status can be predictive markers of malignant transformation of IP. Furthermore, immunohistochemistry of p53 and p16 expression can be surrogate markers for TP53 and CDKN2A status.

A Pilot Immunohistochemical Study Identifies Hedgehog Pathway Expression in Sinonasal Adenocarcinoma.

Tumors of the head and neck, more specifically the squamous cell carcinoma, often show upregulation of the Hedgehog signaling pathway. However, almost nothing is known about its role in the sinonasal adenocarcinoma, either in intestinal or non-intestinal subtypes. In this work, we have analyzed immunohistochemical staining of six Hedgehog pathway proteins, sonic Hedgehog (SHH), Indian Hedgehog (IHH), Patched1 (PTCH1), Gli family zinc finger 1 (GLI1), Gli family zinc finger 2 (GLI2), and Gli family zinc finger 3 (GLI3), on 21 samples of sinonasal adenocarcinoma and compared them with six colon adenocarcinoma and three salivary gland tumors, as well as with matching healthy tissue, where available. We have detected GLI2 and PTCH1 in the majority of samples and also GLI1 in a subset of samples, while GLI3 and the ligands SHH and IHH were generally not detected. PTCH1 pattern of staining shows an interesting pattern, where healthy samples are mostly positive in the stromal compartment, while the signal shifts to the tumor compartment in tumors. This, taken together with a stronger signal of GLI2 in tumors compared to non-tumor tissues, suggests that the Hedgehog pathway is indeed activated in sinonasal adenocarcinoma. As Hedgehog pathway inhibitors are being tested in combination with other therapies for head and neck squamous cell carcinoma, this could provide a therapeutic option for patients with sinonasal adenocarcinoma as well.

Clinical Significance of HMGB1 and Autophagy-Related Genes in Sinonasal Inverted Papilloma.

OBJECTIVES: Sinonasal inverted papilloma (SNIP) is a noncancerous tumor that develops in the mucous membrane of the nasal sinuses. Many malignancies are tightly linked to autophagy, an intracellular self-degradation mechanism. HMGB1 has demonstrated its ability to modulate autophagy in many pathological conditions. This work investigates how HMGB1 and other genes involved in autophagy contribute to SNIP. MATERIAL AND METHODS: The study included 45 patients with SNIP and a control group consisting of 28 individuals. In each group, qPCR was employed to examine the mRNA expression levels of genes correlated with autophagy and HMGB1. HMGB1 and genes associated with autophagy were examined for protein expression levels via Western Blot and immunohistochemical staining assays. At the same time, the association between HMGB1 and genes involved in autophagy was discovered through correlation analysis. Furthermore, Krouse staging was utilized for investigating the expression levels of HMGB1 and other autophagy-related genes at various stages in clinically staged SNIP patients. RESULTS: LC3B, ATG5, and Beclin1 autophagy-related genes and HMGB1 were substantially expressed in SNIP. Additionally, there was a positive correlation between HMGB1 and these genes. During various phases of SNIP, the levels of HMGB1 expression and autophagy-related genes were notably elevated at stage T4 compared with stage T2. CONCLUSION: Clinical staging in SNIP is correlated with HMGB1 expression in conjunction with autophagy-related genes LC3B, ATG5, and Beclin1, suggesting the possibility of novel prognostic indicators. LEVEL OF EVIDENCE: NA Laryngoscope, 134:3941-3946, 2024.

Recurrent Wnt Pathway and ARID1A Alterations in Sinonasal Olfactory Carcinoma.

Sinonasal tumors with neuroepithelial differentiation, defined by neuroectodermal elements reminiscent of olfactory neuroblastoma (ONB) and epithelial features such as keratin expression or gland formation, are a diagnostically challenging group that has never been formally included in sinonasal tumor classifications. Recently, we documented that most of these neuroepithelial neoplasms have distinctive histologic and immunohistochemical findings and proposed the term "olfactory carcinoma" to describe these tumors. However, the molecular characteristics of olfactory carcinoma have not yet been evaluated. In this study, we performed targeted molecular profiling of 23 sinonasal olfactory carcinomas to further clarify their pathogenesis and classification. All tumors included in this study were composed of high-grade neuroectodermal cells that were positive for pankeratin and at least 1 specific neuroendocrine marker. A significant subset of cases also displayed rosettes and neurofibrillary matrix, intermixed glands with variable cilia, peripheral p63/p40 expression, and S100 protein-positive sustentacular cells. Recurrent oncogenic molecular alterations were identified in 20 tumors, including Wnt pathway alterations affecting CTNNB1 (n = 8) and PPP2R1A (n = 2), ARID1A inactivation (n = 5), RUNX1 mutations (n = 3), and IDH2 hotspot mutations (n = 2). Overall, these findings do demonstrate the presence of recurrent molecular alterations in olfactory carcinoma, although this group of tumors does not appear to be defined by any single mutation. Minimal overlap with alterations previously reported in ONB also adds to histologic and immunohistochemical separation between ONB and olfactory carcinoma. Conversely, these molecular findings enhance the overlap between olfactory carcinoma and sinonasal neuroendocrine carcinomas. A small subset of neuroepithelial tumors might better fit into the superseding molecular category of IDH2-mutant sinonasal carcinoma. At this point, sinonasal neuroendocrine and neuroepithelial tumors may best be regarded as a histologic and molecular spectrum that includes core groups of ONB, olfactory carcinoma, neuroendocrine carcinoma, and IDH2-mutant sinonasal carcinoma.

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.

PD-L1 expression, tumor-infiltrating lymphocytes, mismatch repair deficiency, EGFR alteration and HPV infection in sinonasal squamous cell carcinoma.

The antitumor efficacies of immune checkpoint inhibitors (ICIs) and the usefulness of potential predictive markers such as programmed death-ligand 1 (PD-L1) expression, density of tumor-infiltrating lymphocytes (TILs) and microsatellite instability (MSI) in sinonasal squamous cell carcinoma (SNSCC) have not been fully elucidated. We retrospectively analyzed 131 SNSCCs with immunohistochemistry for PD-L1 expression, TIL subpopulations and loss of mismatch repair (MMR) proteins as a surrogate for MSI-high. We also comprehensively evaluated the mutual relationships among these immuno-markers, high-risk human papillomavirus (HPV) infection, epidermal growth factor receptor (EGFR) gene status, and KRAS mutation. PD-L1 expression (tumor proportion score ≥ 1%) was detected in 60 (45.8%) SNSCC cases and was significantly associated with worse overall survival (OS) (p = 0.0240). High density of cluster of differentiation 8 (CD8)-positive TILs was significantly associated with better progression-free survival (PFS) (p = 0.0368), and high density of forkhead box protein P3-positive TILs was significantly associated with better PFS and OS (p = 0.0007 and 0.0143, respectively). With respect to the combination of CD8 + TIL and PD-L1 expression, the high-CD8/PD-L1-negative group showed the most favorable prognosis, whereas the low-CD8/PD-L1-positive group showed the worst prognosis. MMR loss was detected in 3 (2.3%) of the 131 cases. HPV infection (6.1%), EGFR mutation (14.5%), EGFR copy number gain (26%), and MMR loss were essentially mutually exclusive; patients in these molecular groups showed significant differences in prognosis but not in the degree of PD-L1 expression or TILs. Among the nine ICI-treated patients, three (33.3%) were responders, and the EGFR-wild type cases (n = 7) showed better clinical responses to an ICI compared to the EGFR-mutant cases (n = 2). Among the patients with residual/recurrent EGFR-wild type tumors (n = 43), ICI treatment significantly improved OS (p = 0.0281). The results suggest that the evaluation of immuno-markers and molecular subclassification may be helpful for prognostic prediction and selecting an individualized therapeutic strategy for patients with SNSCC.

SMARCB1-deficient carcinomas of the head and neck region: a cytopathologic characterization.

INTRODUCTION: SMARCB1 encodes for a component of the SWI/SNF complex and is widely implicated in carcinogenesis. In the head and neck, SMARCB1-deficient carcinomas typically arise in the sinonasal tract but can be found at other sites. EZH2 inhibitors have emerged as potential targeted therapy against SWI/SNF-deficient tumors. We sought to characterize the cytomorphology of head and neck carcinomas with SMARCB1 deficiencies to identify potential candidates for targeted therapy. MATERIALS AND METHODS: Head and neck carcinomas with SMARCB1 mutations were retrospectively identified and confirmed to be SMARCB1-deficient by both molecular (fluorescent in-situ hybridization or next generation sequencing) and immunohistochemical means. Cases with positive cytology were reviewed and their cytologic features cataloged. RESULTS: A total of 19 specimens from 13 patients were reviewed, including 8 specimens from 7 sinonasal carcinomas, 4 specimens from 3 thyroid carcinomas, 3 specimens from 2 skin carcinomas, and 4 specimens from 1 carcinoma of unknown primary origin. High-grade features were common, including mitoses (11 of 19) necrosis (13 of 19) and multinucleation (16 of 19). Tumors showed either dense cytoplasm with distinct cell borders (10 of 19) or delicate cytoplasm with indistinct cell borders (9 of 19). Most tumors showed no distinct epithelial differentiation (12 of 19), while some (7 of 19) showed glandular or signet ring features. A minor cohort demonstrated rhabdoid cells (4 of 19). CONCLUSIONS: Head and neck carcinomas with SMARCB1 deficiencies have a wide array of morphologies and tend to demonstrate high-grade features. Only a minor cohort demonstrate rhabdoid-type cells. Evaluation of SMARCB1 deficiency for potential targeted therapy should not be limited to tumors with rhabdoid morphology.

PI3K/AKT/mTOR pathway and autophagy regulator genes in paranasal squamous cell carcinoma metastasis.

Although there are many studies on the role of PI3K/AKT/mTOR pathway and autophagy genes in the mechanism of head and neck cancer formation and prognostic significance, there is no study investigating the role of the genes in paranasal sinus carcinomas. The aim of the study was to assess the role of the PI3K/AKT/mTOR pathway and autophagy related gene expression changes in squamous cell carcinoma of paranasal sinuses with and without neck metastasis. Eight paranasal squamous cell carcinoma patients (five without and three with neck metastasis) were included. Tissues were obtained during the surgery. Total RNA was isolated from the tissues and cDNA synthesis was performed. Expression levels of the genes were determined using qRT-PCR method. The results were evaluated using the 2-∆∆Ct method, and fold changes of the gene expression levels in primary tumor and neck metastasis tissues were calculated according to the normal tissue. Expression levels of both PI3K/AKT/mTOR pathway and positive regulators of autophagy were significantly increased in metastasis-related two groups, especially in neck metastasis tissues. The increase in PI3K/AKT/mTOR pathway and autophagy related gene expression levels may support the metastatic character in paranasal squamous cell carcinomas. This is the first study to assess autophagy related genes in paranasal sinus cancer at transcriptome-level. Support of the transcriptome-level findings by the further protein analyses will contribute to the illumination of the rare paranasal sinus cancer molecular biology.

Increase in IL-17-positive cells in sinonasal inverted papilloma.

OBJECTIVE: Neutrophil infiltration in patients with sinonasal inverted papilloma (SNIP) is significantly high. Whether IL-17, which is a potent factor mediating neutrophilic inflammation, is involved in the neutrophilic phenotype of SNIP is investigated in the current study. STUDY DESIGN: Laboratorial study. PARTICIPANTS: Nasal papilloma and inferior turbinate were collected from patients with SNIP (n = 50) and control subjects with septal deviation (n = 15). METHODS: IL-17 + cells were evaluated in tissues obtained from patients with SNIP and control subjects with septal deviation, by immunohistochemistry and flow cytometry. MAIN OUTCOME MEASURES: The IL-17 + cells were mainly localised in mononuclear cells and neutrophils, and were up-regulated in the SNIP samples compared with those in the controls. The IL-17 + T-cell subsets mainly included CD4+ (Th17, 60.0%) and CD8+ (Tc17, 30.0%), and both subsets were enhanced in the SNIP samples than controls. The total level of IL-17 + cells was significantly correlated with neutrophil infiltration in the SNIP tissues. Furthermore, the SNIP homogenates could significantly promote IL-17 production in peripheral blood mononuclear cells. CONCLUSIONS: An increase in IL-17 + cells is evident in SNIP and may be involved in neutrophil infiltration in local tissues. IL-17 could be a potential therapeutic target to relieve the neutrophilic pathological change in SNIP.

HPV-related Sinonasal Carcinoma: Clinicopathologic Features, Diagnostic Utility of p16 and Rb Immunohistochemistry, and EGFR Copy Number Alteration.

The prevalence and prognostic value of human papillomavirus (HPV) infection and epidermal growth factor receptor (EGFR) alteration in sinonasal squamous cell carcinoma (SNSCC) are not known. The reliability of p16 overexpression as a surrogate for HPV infection in SNSCC is also unclear. We investigated the prognostic and diagnostic significances of HPV infection, EGFR alteration, and p16 expression in SNSCC. We analyzed high-risk HPV infection by HPV-RNA in situ hybridization and EGFR gene copy number gain (CNG) by chromogenic in situ hybridization and by determining the protein expressions of p16, Rb, and EGFR by immunohistochemistry in 101 SNSCC cases. HPV infection (n=9, 8.9%) and p16 overexpression (n=15, 14.9%) were associated with better overall survival (P=0.0042 and 0.005, respectively). The HPV cases were located predominantly at the nasal cavity with nonkeratinizing histology and partial loss of Rb. Notably, 40% (6/15) of p16 SNSCCs were HPV. Two of these cases showed complete loss of Rb expression by immunohistochemistry, suggesting a reason for the above discrepancy. EGFR CNG, detected in 30.5% of the SNSCCs, was correlated with EGFR protein overexpression (P=0.0001). HPV infection and EGFR CNG were mutually exclusive. The HPV/EGFR CNG group had significantly better overall survival than the HPV/EGFR CNG and HPV/EGFR CNG groups (P=0.0471 and 0.0343, respectively). Our results suggest that HPV infection is a favorable prognostic marker in SNSCC, but p16 is not a perfect surrogate marker; the Rb expression pattern may improve the diagnostic accuracy. The molecular subclassification of SNSCCs based on HPV infection and EGFR copy number status might provide important information for therapeutic strategies.

Beware of the sneeze.

Switch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), also known as integrase interactor 1-deficient sinonasal carcinoma, is a rare entity that was first described in 2014. Since then, there have been 39 cases published in the literature, with basaloid or plasmacytoid/rhabdoid morphology being the most common pathological subtype. We report a patient with switch/sucrose non-fermentable-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (integrase interactor 1)-deficient sinonasal carcinoma who had permanent vision loss after valsalva-induced acute hemorrhage and resultant orbital compartment syndrome.

ErbB1 and ErbB2 overexpression in patients with sinonasal inverted papilloma and inverted papilloma with squamous cell carcinoma in China.

Background: Currently, the expression patterns of epidermal growth factor receptor (EGFR) family genes in sinonasal inverted papilloma (SNIP) and inverted papilloma with squamous cell carcinoma (IPwSCC) are not clear.Objective: This study aimed to investigate the expression of EGFR family members and their ligands in SNIP and IPwSCC and to analyze their correlations with SNIP histological grade and Krouse stage.Materials and methods: Data from 25 cases of inverted papilloma patients in China were collected and divided into 16 cases in the SNIP group and 9 in the IPwSCC group. In addition, eight cases of normal nasal mucosa (NNM) were collected and used as the control group. The expression levels of EGFR family members and their ligands in the NNM and SNIP groups and EGFR family members in the IPwSCC group were evaluated using immunohistochemistry and qRT-PCR. In addition, their correlations with the SNIP histological grade and Krouse stage were analyzed. The statistical analysis was performed using the GraphPad Prism 7.0 statistical software.Results: The ErbB1 and ErbB2 mRNA and protein expression levels were significantly higher in the SNIP group than in the NNM group (p < .01). The ErbB1 and ErbB2 protein expression levels were significantly higher in the IPwSCC group than those in the NNM and SNIP groups (p < .01). The ErbB1 and ErbB2 mRNA and protein expression levels in the SNIP group were positively correlated with the SNIP dysplasia grade.Conclusion: Upregulation of ErbB1 and ErbB2 expression may be associated with SNIP pathogenesis and carcinogenesis.

Human papillomavirus and infiltration of CD8- and Foxp3-positive immune cells in sinonasal inverted papillomas.

Background: Sinonasal inverted papilloma (IP) is a benign tumor with a high risk of local recurrence and a potential to malignify and Human papillomavirus (HPV) has been suggested an etiological factor. p16INK4a (p16) overexpression is considered a surrogate marker for HPV, but whether p16 and HPV correlate to IP is uncertain. Besides, a prognostic role of tumor infiltrating lymphocytes (TILs) are observed in many tumors, however their role in IP is sparsely studied. Aims/objectives: We hence analyzed IPs for the presence and the prognostic role of HPV and p16 overexpression together with CD8+ and FoxP3+ TILs in a population-based study. Material and methods: 98 IP patients diagnosed 2001-2010 were identified from the Swedish Cancer Registry and analyzed for HPV by PCR and p16, CD8 and FoxP3 was by immunohistochemistry. Results: In total, 12.2% of the IPs were HPV-positive (nine HPV-11, two HPV-6 and one HPV-45). Patients with HPV-positive lesions were younger (p = .003) and tended to present with more dysplasia. No correlation was observed between TILs and prognosis. Conclusions and significance: Our data suggests that patients with HPV-positive IPs present with different clinical characteristics, suggesting possibly different disease entities. Moreover, recurrences may occur >5 years, which should be considered in the follow-up.

HER2 status in sinonasal intestinal-type adenocarcinoma.

Given that the prognosis of patients with sinonasal intestinal-type adenocarcinoma (ITAC) has not significantly changed recently, there is a desire for new therapeutic approaches to improve clinical management. HER2-targeted therapy has remarkably improved the overall survival of patients with HER2 amplified tumors. To date, HER2 assessment has produced contradictory results in ITAC. The aim of this study was to assess HER2 status at both protein and DNA levels in a large series of ITAC. HER2 status was assessed by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) in forty-three patients that underwent surgical resection for ITAC at the Otorhinolaryngology Section, Padua University Hospital, between 2007 and 2016. IHC was evaluated using the four-tier score developed for gastroesophageal cancer. As for IHC, 83.7% (36/43) of ITAC were scored 0, 14% (6/43) 1+, and 2.3% (1/43) 2+. No HER2 amplification was detected by CISH. The present is the largest study of sinonasal ITAC tested with both IHC and CISH confirmation for HER2 status. No HER2 overexpression/amplification was detected. Contrary to previous studies, our findings seem to rule out any oncogenetic role of HER2 in ITAC pathogenesis.

Immunohistochemical profiling of mucins in sinonasal adenocarcinomas.

In this study we investigated the expression of mucins (MUC1, MUC2, MUC4, MUC5AC and MUC6) in a series of 66 sinonasal adenocarcinomas, in order to establish their distribution and the possible correlation with clinicopathological and prognostic parameters. The series included 51 intestinal type adenocarcinomas, 4 non-intestinal type adenocarcinomas, and 11 salivary gland type carcinomas. The immunohistochemical analysis was conducted on a tissue microarray obtained from formalin fixed-paraffin embedded tumor tissue samples. Thirty-nine adenocarcinomas (59.1%) resulted positive for MUC1, 21 (41.2%) for MUC2, 47 (71.2%) for MUC4, and 16 (24.2%) for MUC5AC, while MUC6 was negative in all cases tested. MUC1 was significantly more expressed in ITACs than in non-ITACs (70% vs 20%, p = 0.0007) while MUC2 was expressed only in ITACs (p = 0.0015) with a clear prevalence in the mucinous subtype (p < 0.0001). Conversely, MUC4 and MUC5AC were similarly expressed in the sinonasal adenocarcinoma subtypes tested. High expression of MUC 1 was related to a significantly shorter overall survival, both in the whole series (p = 0.04), while adenocarcinomas positive for MUC 2 tended to have a worse overall survival (p = 0.07). In addition, MUC2 expression was higher in ITACs with distant metastasis, being expressed in 4 out of 5 cases (p = 0.015). We conclude that sinonasal adenocarcinomas have a characteristic expression of different mucin types, with significant clinicopathologic correlations. In view of the extensive involvement of mucins in different aspects of tumor growth and their emerging role as possible therapeutic targets, our study suggests that these factors could be considered clinically relevant biomarkers and attractive targets for new treatments in sinonasal adenocarcinomas.