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.

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.

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.

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.

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.

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.

Putative biomarkers of malignant transformation of sinonasal inverted papilloma into squamous cell carcinoma.

OBJECTIVE: To compare genome-wide DNA methylation between samples of sinonasal inverted papilloma (SNIP) and squamous cell carcinoma (SCC) samples in order to identify aberrantly methylated genes that might be involved in malignant transformation. METHODS: Tissue samples were collected from patients. DNA methylation in C-phosphate-G islands and gene promoters was analysed using a DNA methylation microarray kit. The levels of mRNA or protein from aberrantly methylated genes were measured using real-time polymerase chain reaction or Western blot analysis. RESULTS: A total of 27 tissue samples were included in this study; 15 SNIP samples and 12 SCCs arising in SNIPs. A total of 11 201 nominally differentially methylated sites were observed between SNIP and SCC arising in SNIPs. Six sites were significantly different at P < 0.01 and contained three genes ( MIR661, PLEC and OPA3). These three genes were hypermethylated. In addition, the levels of mature miR-661 mRNA and PLEC protein were significantly upregulated in SCC tissues compared with SNIP samples. The levels of OPA3 protein were downregulated in SCC tissues compared with SNIP samples. CONCLUSIONS: This study demonstrated hypermethylation and abnormal expression of the MIR661, PLEC and OPA3 genes, suggesting a role for their involvement in the malignant transformation of SNIP.

SMARCB1-Deficient Sinonasal Carcinoma: A Case Report and Discussion of the Clinical Implications.

OBJECTIVE: SMARCB1-deficient sinonasal tract carcinomas are an emerging subset of rare tumors recently described in the literature, with less than 100 reported cases. Given the aggressive nature of this tumor, timely diagnosis is especially important. We present a case report of a SMARCB1-deficient carcinoma of the sinonasal tract. METHODS: Case report with review of the literature. RESULTS: The patient was a 53-year-old male with computed tomography (CT)-proven mass of the right ethmoid and sphenoid sinuses. Rigid nasal endoscopy revealed a purple mass completely obstructing the right nasal cavity that extended inferiorly from the posterior ethmoids and sphenoid sinuses. Initial biopsy in the emergency room was nondiagnostic due to extensive tumor necrosis. Magnetic resonance imaging (MRI) revealed T2 hypointense enhancing mass centered in the right posterior ethmoids with invasion into the right orbital apex, classifying it as a T4b tumor. The patient underwent repeat biopsy with frozen section and tumor debulking. Immunohistochemical analysis of subsequent biopsy revealed complete loss of INI-1 and negative staining for other pertinent markers, alluding to the diagnosis of SMARCB1-deficient sinonasal tract carcinoma. CONCLUSION: Tumor necrosis may be problematic in obtaining a diagnosis for SMARCB1-deficient sinonasal carcinomas. Thus, sampling various regions of the tumor during initial biopsy can prevent delays in diagnosis and treatment.

Predictive value of EGFR-PI3K-pAKT-mTOR-pS6 pathway in sinonasal squamous cell carcinomas. / Valor pronóstico de la ruta de EGFR-PI3K-pAKT-mTOR-pS6 en los carcinomas epidermoides nasosinusales.

BACKGROUND AND OBJECTIVES: We have previously indicated that EGFR has a role in carcinogenesis in a subgroup of sinonasal squamous cell carcinomas (SNSCC). In addition, EGFR activates 2 of the most important intracellular signalling pathways: PI3K/pAKT/mTOR/pS6 and MAP pathway kinases. The objective of this study was to evaluate the involvement of the EGFR/PI3K/pAKT/mTOR/pS6 pathway and its relationship with clinical-pathological parameters and follow-up of sinonasal squamous cell carcinoma. MATERIAL AND METHODS: The immunohistochemical expression of different components of the PI3K/AKT/mTOR/pS6 pathway and its relationship with various clinical-pathological parameters was studied in a series of 54 patients with SNSCC. RESULTS: Loss of PTEN expression was observed in 33/54 cases (61%) and pAKT, mTOR and pS6 pre-expression was observed in 19/54 cases (35%), 8/54 cases (15%), and 47/54 cases (87%), respectively. Loss of PTEN expression was related to intracranial invasion and development of regional metastases (p=0.005). Overexpression of pS6 was associated with a decrease in survival (p=0.008), presence of local recurrences (p=0.055), and worsening of overall prognosis (p=0.007). No significant relationships were observed between pAKT and mTOR expression and the clinicopathological parameters studied. CONCLUSIONS: Alterations in the expression of EGFR/PI3K/pAKT/mTOR/pS6 pathway components are common in a subgroup of SNSCC. This study reveals that the absence of pS6 overexpression is associated with better clinical outcomes. Therefore, pS6 expression could be considered as an unfavourable prognostic marker.

Sino-orbital desmoid tumor in a pediatric patient - Case report with review of literature.

We report a case of a 2-year-old female who presented with bilateral progressive proptosis, visual loss, nasal obstruction, and breathing difficulty. Magnetic resonance imaging revealed a large sino-orbital mass that was extending to the orbital apex and skull base. An initial diagnosis of rhabdomyosarcoma was made elsewhere on the basis of the presence of round and spindle cell tumor. Subsequent biopsy with immunohistochemical staining was positive for nuclear staining with ß-catenin, shifting the diagnosis to a myofibroblastic tumor, favoring desmoid-type fibromatosis. With image guidance, near complete excision of tumor was performed by a multidisciplinary team, while respecting danger zones such as the skull base and the optic nerve. Following a recurrence over 2 months, additional excision was performed with a 6-month treatment of methotrexate and vinblastine. Desmoid tumor is a rare form of soft tissue tumor uncommonly seen in the orbital area. Although benign, it is known to be recurrent and infiltrative. Few data are known and further information will aid in the management of these tumors.

Utility of FDG PET/CT in the Characterization of Sinonasal Neoplasms: Analysis of Standardized Uptake Value Parameters.

OBJECTIVE: We aimed to evaluate the contribution of different standardized uptake value (SUV) parameters generated from pretreatment 18F-FDG PET/CT in the characterization of sinonasal neoplasms with histopathologic correlations. MATERIALS AND METHODS: This retrospective study included 97 consecutive patients (58 men, 39 women; age range, 20-93 years; mean age, 62 years) with pathologically proven untreated sinonasal neoplasms who underwent FDG PET/CT from February 2010 to August 2017. Semiquantitative analysis of primary tumors were performed to evaluate the maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and the ratio of the SUVmax of the primary tumor to the SUVmean of mediastinal blood pool, which we refer to here as " SUVratio." Various sinonasal tumor histopathologic subgroups (n = 14) were analyzed. The Kruskal-Wallis test was used to compare the SUVmax, SUVmean, and SUVratio with the histopathologic diagnosis. RESULTS: Mean values of SUVmax, SUVmean, and SUVratio for the sinonasal neoplasms were 16.6 ± 9.7 (SD), 8.6 ± 5.1, and 5.9 ± 3.7, respectively, and each parameter was significantly different between histopathologic types (p < 0.05). Mean values of SUVmax, SUVmean, and SUVratio were higher in sinonasal undifferentiated carcinoma (SNUC) than in olfactory neuroblastoma, metastasis, and adenoid cystic carcinoma (p < 0.05). Mean values of SUVmax and SUVmean were higher in squamous cell carcinoma (SCC) than in olfactory neuroblastoma and metastasis (p < 0.05). Also, mean SUVmax was higher in SCC and SNUC than in poorly differentiated carcinoma (p < 0.05). Mean SUVratio was higher in SCC than in small cell carcinoma, olfactory neuroblastoma, and adenoid cystic carcinoma (p < 0.05). CONCLUSION: We conclude that different SUV parameters from FDG PET/CT can be used as so-called "metabolic biopsy" to categorize sinonasal neoplasms into different histopathologic subgroups because it can help in the characterization of some of the more common subgroups of sinonasal neoplasms. However, we found that there is overlap in FDG uptake values among some of the rare histologic subgroups; hence, surgical biopsy is still needed for differentiation of histologic subtypes of aggressive sinonasal masses.

Sinonasal malignant melanoma with metastasis: Immunohistochemistry meeting the diagnostic challenge.

Sinonasal malignant melanoma is one of the uncommon and highly aggressive tumors of the sinonasal cavity. Cytomorphological features in a metastatic lymph node may reveal a diagnosis of malignant melanoma. This case had nondiagnostic cytological and histopathological features, which could suggest malignant melanoma. Immunohistochemistry in such cases becomes the primary method for establishing the diagnosis of malignant melanoma at an uncommon site.