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-related multiphenotypic sinonasal carcinoma: A report of two patients and review of the literature

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is a recently described sinonasal tract tumor that is associated with high-risk HPV subtype infection. Despite histological features that are suggestive of a high-grade malignant tumor, the prognosis of HMSC is relatively good; however, the clinical features of this tumor are poorly understood. Here, we describe two patients with HMSC. The first was initially diagnosed with adenoid cystic carcinoma of the right nasal cavity; the tumor was extirpated via endoscopic endonasal surgery. Seventy-four months later, the tumor recurred in the right inferior turbinate and was diagnosed as HMSC after biopsy, whereupon it was resected en block via endoscopic endonasal surgery. No adjuvant therapy was administered during either episode; moreover, no recurrences have occurred during the 44 months since the second operation. The second patient was diagnosed with HMSC based on the biopsy of the tumor occupying the left nasal cavity. The tumor was completely resected under endoscopic endonasal surgery, and no adjuvant therapy was administered. There has been no recurrence for 15 months after the operation. Herein, we also review the clinical features of this tumor type based on 69 previously reported cases as well as our patients.

Towards a Molecular Classification of Sinonasal Carcinomas: Clinical Implications and Opportunities

Simple Summary

In recent years, there have been several molecular and immunohistochemical additions to the pathologic diagnosis of sinonasal malignancies that could facilitate the identification of clinically relevant groups of sinonasal malignancies. Molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this article we review the recent literature on molecular analysis and/or subtyping of sinonasal carcinomas and we discuss the possible clinical implications of a classification of sinonasal tumors based on their molecular features.

Abstract

Sinonasal carcinomas are a heterogeneous group of rare tumors, often with high-grade and/or undifferentiated morphology and aggressive clinical course. In recent years, with increasing molecular testing, unique sinonasal tumor subsets have been identified based on specific genetic alterations, including protein expression, chromosomal translocations, specific gene mutations, or infection by oncogenic viruses. These include, among others, the identification of a subset of sinonasal carcinomas associated with HPV infection, the identification of a subset of squamous cell carcinomas with EGFR alterations, and of rare variants with chromosomal translocations (DEK::AFF2, ETV6::NTRK and others). The group of sinonasal adenocarcinomas remains very heterogeneous at the molecular level, but some recurrent and potentially targetable genetic alterations have been identified. Finally, poorly differentiated and undifferentiated sinonasal carcinomas have undergone a significant refinement of their subtyping, with the identification of several new novel molecular subgroups, such as NUT carcinoma, IDH mutated sinonasal undifferentiated carcinoma and SWI/SNF deficient sinonasal malignancies. Thus, molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this review, we summarize the recent developments in the molecular characterization of sinonasal carcinomas and we discuss how these findings are likely to contribute to the classification of this group of rare tumors, with a focus on the potential new opportunities for treatment.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Nasal Cavity, Paranasal Sinuses and Skull Base

The World Health Organization Classification of Head and Neck Tumours recently published the 5th edition. There are new entities, emerging entities, and significant updates to the taxonomy and characterization of tumor and tumor-like lesions, specifically in this article as it relates to nasal cavity, paranasal sinuses and skull base. Importantly, the number of diagnostic entries has been reduced by creating category-specific chapters for soft tissue, hematolymphoid, melanocytic, neuroectodermal, and metastatic tumors. Bone and salivary gland tumors are also not separately reported in the sinonasal tract, but included in the jaw and salivary gland sections, respectively. Repetition of characteristic entities in each anatomic site was also reduced, instead highlighting only the unique features in each anatomic site. Two new entities (SWI/SNF complex-deficient sinonasal carcinomas and HPV-related multiphenotypic sinonasal carcinoma) will be highlighted in this review, with a discussion of several emerging entities. There is a short description of updated information for all 24 diagnostic entities included in this edition to allow the reader a snapshot of current state of knowledge, but to encourage more investigation and further broaden understanding of these diverse and rare entities.

Prevalence of human papillomavirus in head and neck cancers at tertiary care centers in the United States over time

BACKGROUND

Human papillomavirus (HPV) is responsible for a growing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) among men and White individuals. Whether similar trends apply to women, non‐Whites, and non‐oropharyngeal squamous cell carcinomas (non‐OPSCCs) is unknown.

METHODS

This is a cross‐sectional analysis combining 2 multi‐institutional case series of incident head and neck squamous cell carcinoma (HNSCC) cases. Incident HNSCCs from 1995 to 2012 were enrolled retrospectively using banked tumor samples and medical record abstraction. Incident HNSCCs from 2013 to 2019 were enrolled prospectively. The prevalence of tumor HPV biomarkers was tested over 3 time periods (1995‐2003, 2004‐2012, and 2013‐2019). Centralized testing was done for p16 immunohistochemistry (p16) and oncogenic HPV in situ hybridization (ISH).

RESULTS

A total of 1209 incident cases of HNSCC were included. Prevalence of p16‐ and ISH‐positive tumors increased significantly for oropharynx cancers over time. The majority were positive after 2013 for White patients (p16, 92%; P < .001; ISH 94%; P < .001), Black patients (p16, 72%; P = .021; ISH 67%; P = .011), and Hispanic patients (p16, 100%; P = .04; ISH 100%; P = .013). For women with OPSCC, the prevalence of p16‐ and ISH‐positive tumors increased significantly to 82% (P < .001) and 78% (P = .004), respectively. For non‐OPSCCs, there was increased p16 and ISH positivity overall with 24% p16 and 16% ISH positivity in the most recent time period (P < .001 for both).

CONCLUSIONS

The majority of OPSCCs in US tertiary care centers are now p16 and ISH positive for all sex and race groups. In some populations in the United States, 91% of OPSCCs are now caused by HPV. Few non‐OPSCCs are p16 and ISH positive.

This study evaluates the prevalence of p16 and in situ hybridization positivity in head and neck cancers over time. This study shows an increase in prevalence over time among women and non‐Whites, 2 groups that are understudied in the epidemiology of human papillomavirus.

Molecular Biomarkers in Sinonasal Cancers: New Frontiers in Diagnosis and Treatment

Purpose of Review

Sinonasal tumors are rare and heterogeneous diseases which pose challenges in diagnosis and treatment. Despite significant progress made in surgical, oncological, and radiotherapy fields, their prognosis still remains poor. Therefore, alternative strategies should be studied in order to refine diagnosis and improve patient care.

Recent Findings

In recent years, in-depth molecular studies have identified new biological markers, such as genetic abnormalities and epigenetic variations, which have allowed to refine diagnosis and predict prognosis. As a consequence, new histological entities have been described and specific subgroup stratifications within the well-known histotypes have been made possible. These discoveries have expanded indications for immunotherapy and targeted therapies in order to reduce tumor spread, thus representing a valuable implementation of standard treatments.

Summary

Recent findings in molecular biology have paved the way for better understanding and managing such rare and aggressive tumors. Although further efforts need to be made in this direction, expectations are promising.

Development of head and neck pathology in Europe

This review gives a brief history of the development of head and neck pathology in Europe from a humble beginning in the 1930s to the explosive activities the last 15 years. During the decades before the introduction of immunohistochemistry in the 1980s, head and neck pathology grew as a subspeciality in many European countries. In the late 1940s, the Institute of Laryngology and Otology with its own pathology laboratory was founded in London, and in 1964 the World Health Organization (WHO) International Reference Centre for the Histological Classification of Salivary Tumours was established at the Bland-Sutton Institute of Pathology, also in London. International collaboration, and very much so in Europe, led to the publication of the first WHO Classification of Salivary Gland Tumours in 1972. In the 1960s, a salivary gland register was organised in Hamburg and in Cologne the microlaryngoscopy was invented enabling microscopic endoscopic examination and rather shortly afterwards a carbon dioxide laser attached to the microscope became established and laryngeal lesions could be treated by laser vaporisation. During the last three decades, the use of immunohistochemistry supplemented with cytogenetic and refined molecular techniques has greatly facilitated the pathological diagnostics of head and neck lesions and has had a huge impact on research. Collaboration between different European centres has drastically increased partly due to establishment of scientific societies such as the Head and Neck Working Group (HNWG) within the European Society of Pathology and the International Head and Neck Scientific Group (IHNSG). A very large number of European pathologists have contributed to the 2nd, 3rd and 4th WHO books, and are involved in the upcoming 5th edition. Accredited educational meetings and courses are nowadays regularly arranged in Europe. Numerous textbooks on head and neck pathology have been written and edited by European pathologists. The increased collaboration has created larger series of tumours for research and new entities, mainly defined by their genetic abnormalities, are continuously emerging from Europe, particularly regarding salivary gland neoplasms and "undifferentiated" sinonasal tumours. These findings have led to a better and more precise classification and open the possibilities for new treatment strategies.

EGFR Exon 20 Insertion Mutations in Sinonasal Squamous Cell Carcinoma

Recurrent epidermal growth factor receptor (EGFR)-activating mutations have been identified in a rare form of head and neck cancer known as sinonasal squamous cell carcinoma (SNSCC), a malignant disease with a 5-year mortality rate of ~40%. Interestingly, the majority of EGFR mutations identified in patients with primary SNSCC are exon 20 insertions (Ex20ins), which is in contrast to non-small-cell lung cancer (NSCLC), where the EGFR exon 19 deletion and L858R mutations predominate. These studies demonstrate that EGFR Ex20ins mutations are not exclusive to lung cancer as previously believed, but are also involved in driving SNSCC pathogenesis. Here we review the landscape of EGFR mutations in SNSCC, with a particular focus on SNSCC associated with inverted sinonasal papilloma (ISP), a benign epithelial neoplasm. Taking lessons from NSCLC, we also discuss potential new treatment options for ISP-associated SNSCC harbouring EGFR Ex20ins in the context of targeted therapies, drug resistance and precision cancer medicine. Moving forward, further basic and translational work is needed to delineate the biology of EGFR Ex20ins in SNSCC in order to develop more effective treatments for patients with this rare disease.

Metastatic HPV-Mediated Adenocarcinoma Arising from a Base of Tongue Primary: A Case Report with Cytomorphology and Molecular Findings with Review of the Literature

Human papillomavirus (HPV)-mediated squamous cell carcinomas of the oropharynx are common, however only rare cases of HPV-mediated oropharyngeal adenocarcinoma have been reported to date. In this report, we describe a 50 year old nonsmoking male who originally presented with an enlarging neck mass. Fine needle aspiration cytology confirmed an HPV-mediated adenocarcinoma. Subsequent surgery identified a 0.7 cm base of tongue primary HPV-mediated carcinoma with focal glandular differentiation and a 4.0 cm cystic lymph node metastasis demonstrating entirely glandular differentiation. Next generation sequencing of the metastasis detected a pathogenic NOTCH1 mutation.

Trends in HPV Testing for Patients With Sinonasal Squamous Cell Carcinoma: A National Analysis

OBJECTIVE

The objective of this study was to analyze national trends in human papillomavirus (HPV) testing for patients diagnosed with sinonasal squamous cell carcinoma (SNSCC).

STUDY DESIGN

Retrospective database study.

SETTING

National Cancer Database (2010-2016).

METHODS

Cases from 2010 to 2016 with a primary SNSCC diagnosis and known HPV testing status were extracted from the National Cancer Database. Univariate and multivariate analyses were then performed to assess differences in socioeconomic, hospital, and tumor characteristics between tested and nontested patients.

RESULTS

A total of 2308 SNSCC cases were collected, with 1210 (52.4%) HPV tested and 1098 (47.6%) not tested. On univariate analyses, patient age, insurance, income quartile, population density, treatment facility location, and tumor grade were significantly associated with HPV testing status. After multivariate logistic regression modeling, living in a suburban area had lower odds of HPV testing as compared with living in urban areas (odds ratio, 0.74 [95% CI, 0.55-0.99]; P = .041), while tumor grade III/IV had higher odds than grade I (odds ratio, 1.73 [95% CI, 1.29-2.33]; P < .001). HPV-tested patients had a similar 5-year overall survival to nontested patients (48.3% vs 45.3%, log-rank P = .405). A sharp increase in HPV testing rates was observed after 2010 (P < .001).

CONCLUSION

Among patients with SNSCC, those with high-grade tumors were more likely to be tested for HPV, while patients with a suburban area of residence were less likely. Additionally, there was no significant survival benefit to HPV testing, with tested and nontested groups having similar overall survival.

LEVEL OF EVIDENCE

4.

SMARCA4/BRG1-Deficient Sinonasal Carcinoma: Morphologic Spectrum of an Evolving Entity

CONTEXT.—

Molecular analysis of poorly differentiated/undifferentiated sinonasal neoplasms has resulted in identification of a growing number of genetically defined tumors. SMARCA4-deficient sinonasal carcinoma is one such recently described entity that emerged from within sinonasal undifferentiated carcinoma (SNUC), neuroendocrine carcinoma (NEC), and teratocarcinosarcoma (TCS).

OBJECTIVE.—

To identify SMARCA4-deficient sinonasal carcinomas from a large institutional cohort of poorly differentiated/undifferentiated carcinomas and evaluate their clinicopathologic features.

DESIGN.—

SMARCA4/BRG1 immunohistochemistry was performed on all tumors diagnosed as SNUC, poorly differentiated carcinoma, NEC, and TCS during a 12-year period. SMARCA2/BRM and INSM1 immunostaining was performed in SMARCA4-deficient cases.

RESULTS.—

Twelve SMARCA4-deficient sinonasal carcinomas were identified among 299 cases. Morphologically, 5 cases were large cell NEC, 2 cases were small cell NEC, and 5 were TCS. SMARCA4 loss was diffuse and complete in 10 cases, while 2 cases showed focal retention. Most cases showed diffuse cytokeratin staining accompanied by weak, usually focal staining for chromogranin and synaptophysin. INSM-1 showed negativity in most cases. All cases showed retained SMARCA2 expression. IDH1/2 mutation was absent in all cases analyzed. Four of 7 patients died of disease, and aggressive multimodality treatment had better outcome.

CONCLUSIONS.—

SMARCA4-deficient sinonasal carcinomas are morphologically akin to sinonasal poorly differentiated NECs and TCS, display cytokeratin positivity and only focal staining for neuroendocrine markers, and have aggressive biological behavior. Inclusion of SMARCA4 in the immunohistochemical panel for diagnostic workup of all sinonasal NEC and TCS phenotypes will facilitate their early recognition. Comprehensive germline and somatic mutational analyses of these tumors are necessary for further insights into their molecular pathogenesis.

Undifferentiated and dedifferentiated head and neck carcinomas

Undifferentiated carcinomas arising at salivary gland and head and neck mucosal sites may originate either de novo or through a process of dedifferentiation of a differentiated carcinoma. While in the latter group the diagnosis is largely dependent on the identification of the differentiated component or recognition of a specific genotype, the classification of undifferentiated carcinomas that lack a differentiated component is mainly based on the identification of specific genetic drivers, like for example the NUTM1 fusions in NUT carcinoma. A further category is represented by virus associated carcinomas (mainly HPV and EBV), that frequently displays an undifferentiated morphology. Overall, these tumors often represent a diagnostic challenge, especially in small biopsies. This review summarizes and discuss the diagnostic approach to the main head and neck carcinoma types that frequently or occasionally display an undifferentiated appearance, with a focus on salivary gland, oropharyngeal, nasopharyngeal and sinonasal subsites.

Human Papillomavirus-Related Multiphenotypic Sinonasal Carcinoma-An Even Broader Tumor Entity?

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is a recently defined tumor subtype with apparent favorable clinical outcome despite aggressive histomorphology. However, in recent years, additional numbers of cases, with more variable features and at locations outside the sinonasal region, have complicated the definition of HMSC. Here, we have performed a systematic review of all cases described so far in order to accumulate more knowledge. We identified 127 articles published between 2013 and 2021, of which 21 presented unique cases. In total, 79 unique patient cases were identified and their clinical and micromorphological nature are herein summarized. In our opinion, better clinical follow-up data and a more detailed tumor characterization are preferably needed before HMSC can finally be justified as its own tumor entity.

Impact of human papillomavirus in sinonasal cancer-a systematic review

BACKGROUND

Human papillomavirus (HPV) is an established prognostic marker in oropharyngeal squamous cell carcinoma. Currently, the role of HPV in sinonasal carcinoma is being explored.

OBJECTIVES

This systematic review addresses the role of HPV in sinonasal cancer, establishing the occurrence of HPV-positive cancers and the influence of HPV-positivity on prognosis in sinonasal cancer as well as the utility of the putative surrogate marker of HPV (p16) in sinonasal cancer.

MATERIAL AND METHODS

Studies were identified with searches of Medline via PubMed and Embase via OVID (4 May 2020). Articles on original research concerning sinonasal cancer and HPV in humans written in English were included. Case reports with less than five cases were excluded.

RESULTS

Initially, 545 articles were identified; 190 duplicate articles were removed leaving 355 articles for title/abstract screening. Title/abstract screening excluded 243 articles, leaving 112 studies assessed for eligibility. After full-text screening, 57 studies were included. All articles investigated the significance of HPV in sinonasal carcinomas. HPV was reported in approximately 30% of sinonasal squamous cell carcinoma (SNSCC), where it was associated with a better prognosis. In sinonasal cancer, p16 is associated with diagnostic pitfalls and a putative utility of p16 in SNSCC has yet to be established. HPV was not frequently reported in other types of sinonasal carcinomas, besides the recently described subtype, HPV-dependent Multiphenotypic Sinonasal Carcinoma. In other types of sinonasal carcinoma, HPV is not frequently found.

CONCLUSION

Approximately 30% of SNSCC are HPV-positive. HPV-positivity in SNSCC is associated with improved survival. HPV occurs only rarely in other sinonasal cancers. There is currently not sufficient evidence for p16 as a surrogate marker of HPV in SNSCC.

Human papillomavirus-related multiphenotypic sinonasal carcinoma: a clinico-pathological dilemma case report

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC), is a new entity that is restricted to the sinonasal tract and is associated with high-risk HPV. This tumor is suggested to have an indolent behavior with a better prognosis than other carcinomas. We report a unique case of HMSC with a locally aggressive behavior. It is about a 61-year-old men presented with 12 months of unilateral progressive olfactory dysfunction accompanied by exophthalmia of the left eye, declining vision and headaches for 6 months. Computed tomography imaging revealed a voluminous mass occupying the ethmoid, maxillary and frontal sinus with bony destruction of the left ethmoidal blade. Histology showed a tumor composed of variably sized nests, separated by thick mucoid stroma. Tumor cells are plasmacytoid with hyperchromatic nuclei and frequent mitoses. Immunohistochemistry revealed that these cells were positive for cytokeratin AE1/AE3, p16 and negative for CK7, CK20, CD117, p40, p63, S100, synaptophysin and chromogranin.

A Novel Ciliated, Mucin-producing Variant of HPV-related Cervical Adenosquamous Carcinoma In Situ: A Case Report

Uterine cervical adenosquamous carcinoma in situ was originally defined as having either a uniform population of cells with features intermediate in appearance between glandular and squamous cells, or a mixture of distinct glandular and squamous components within a single lesion. The former type would likely be reclassified today as stratified mucin-producing intraepithelial lesion, while the latter type is vanishingly rare. Here, we report a novel case of bona fide adenosquamous carcinoma in situ, which exhibits 2 morphologically and immunophenotypically distinct components: (1) an inner glandular component composed of a single layer of p40-negative, ciliated, mucin-producing dysplastic columnar cells and (2) an outer p40-positive, stratified dysplastic squamous component otherwise identical to cervical intraepithelial neoplasia-3. Both components show block-positive staining for p16 and are positive for high-risk human papillomavirus RNA by in situ hybridization. Our finding expands the histological spectrum of human papillomavirus-associated preinvasive cervical lesions while also providing further evidence that human papillomavirus-driven processes can exhibit ciliated morphology.

Malignant Sinonasal Tumors: Update on Histological and Clinical Management

Tumors of nasal cavity and paranasal sinuses (TuNSs) are rare and heterogeneous malignancies, presenting different histological features and clinical behavior. We reviewed the literature about etiology, biology, and clinical features of TuNSs to define pathologic features and possible treatment strategies. From a diagnostic point of view, it is mandatory to have high expertise and perform an immunohistochemical assessment to distinguish between different histotypes. Due to the extreme rarity of these neoplasms, there are no standard and evidence-based therapeutic strategies, lacking prospective and large clinical trials. In fact, most studies are retrospective analyses. Surgery represents the mainstay of treatment of TuNSs for small and localized tumors allowing complete tumor removal. Locally advanced lesions require more demolitive surgery that should be always followed by adjuvant radio- or chemo-radiotherapy. Recurrent/metastatic disease requires palliative chemo- and/or radiotherapy. Many studies emphasize the role of specific genes mutations in the development of TuNSs like mutations in the exons 4-9 of the TP53 gene, in the exon 9 of the PIK3CA gene and in the promoter of the TERT gene. In the near future, this genetic assessment will have new therapeutic implications. Future improvements in the understanding of the etiology, biology, and clinical features of TuNSs are warranted to improve their management.

Long-term Outcomes from Proton Therapy for Sinonasal Cancers

PURPOSE

To report long-term disease control, survival, and toxicity after proton therapy for sinonasal cancer.

PATIENTS AND METHODS

We reviewed 143 cases of adults with nonmetastatic sinonasal cancers treated with primary (18%; n = 26) or adjuvant (82%; n = 117) proton therapy. The most common histologies were squamous cell carcinoma (29%; n = 42), olfactory neuroblastoma (23%; n = 33), and adenoid cystic carcinoma (16%; n = 23). Patients had predominantly advanced-stage disease (T3, 24%, n = 35; T4, 66%, n = 94) and high-grade histology (52%; n = 74). Surgery included endoscopic resection alone (50%) with craniotomy (10%) or open resection (40%), and 31% had gross disease present at radiotherapy. Most (91%) received high-dose (median, 73.6 Gy radiobiological equivalent [GyRBE]; 84% >70 GyRBE) passive-scatter proton therapy using accelerated hyperfractionation (1.2 GyRBE twice daily) and concurrent chemotherapy (70%). Univariate and multivariate models assessed prognostic factors. Grade 3+ toxicities were recorded per Common Terminology Criteria, version 4. Median follow-up was 3.4 years (range, 0.1-12.5 years) overall and 4.9 years (range, 0.9-12.5 years) for living patients.

RESULTS

The 5-year outcomes were as follows: local control (LC), 80%; neck control, 96%; local-regional control, 78%; freedom from distant metastases, 71%; and disease-free survival, 62%; cause-specific survival, 64%; and overall survival, 59%. Surgery improved LC, but only with gross total resection (5-year LC 87% versus subtotal resection 62.9%, and biopsy alone 55% (P < 0.001). Gross residual disease was the only significant prognostic factor for local-regional control on multivariate analysis. High-grade, T4, and local recurrence were associated with decreased overall survival. Late (G3+) toxicity occurred in 22% (32 of 143), including central nervous system necrosis and vision loss in 6% (9 of 143) and 3.5% (5 of 143), respectively.

CONCLUSION

Proton therapy after gross-total resection provides excellent long-term LC in patients with locally advanced, high-grade sinonasal cancer. Moreover, LC remains strongly associated with long-term survival. With gross disease, about 60% of patients had long-term LC with proton therapy and induction or concurrent chemotherapy.

Sinonasal Squamous Cell Carcinoma, a Narrative Reappraisal of the Current Evidence

Simple Summary

Sinonasal squamous cell carcinomas are a group of diverse tumors affecting the nasal cavity and paranasal sinuses. As a direct consequence of their rarity and heterogeneity, diagnosis is challenging, and treatment does not follow universally accepted protocols. Though surgery represents the mainstay of treatment, neoadjuvant and adjuvant therapies have pivotal roles in improving outcomes of patients treated with curative intent. Indications to endoscopic surgery have been expanding over the last three decades, but a considerable number of patients affected by sinonasal squamous cell carcinoma still need open surgical procedures. Management of the neck in patients affected by sinonasal squamous cell carcinoma is controversial. Curative-intended treatment of recurrent and/or metastatic tumors, alongside palliation of uncurable cases, represent poorly explored aspects of this disease.

Abstract

Sinonasal squamous cell carcinoma is a rare tumor affecting the nasal cavity and paranasal sinuses. Several aspects of this disease, ranging from epidemiology to biology, pathology, diagnosis, staging, treatment, and post-treatment surveillance are controversial, and consensus on how to manage this sinonasal cancer is lacking. A narrative literature review was performed to summarize the current evidence and provide the reader with available data supporting the decision-making process in patients affected by sinonasal squamous cell carcinoma, alongside the authors’ personal opinion on the unsolved issues of this tumor. The review has highlighted several advances in molecular definition of epithelial cancers of the sinonasal tract. Surgery represents the pivot of treatment and is performed through an endoscopic transnasal approach whenever feasible. Open surgery is required for a large proportion of cases. Reconstruction of the defect follows principles of skull base and cranio-maxillo-facial reconstruction. Chemotherapy is given as neoadjuvant treatment or concomitantly to radiotherapy. Photon-based radiation therapy has a crucial role in the adjuvant setting. Particle therapy is providing promising results. Management of the neck should be planned based on the presence of clinically appreciable metastases, primary tumor extension, and need for recipient vessels. Biotherapy and immunotherapy are still underexplored therapeutical modalities.

MYB RNA In Situ Hybridization Facilitates Sensitive and Specific Diagnosis of Adenoid Cystic Carcinoma Regardless of Translocation Status

Adenoid cystic carcinoma (AdCC) can demonstrate histologic and immunohistochemical (IHC) overlap with a wide range of salivary and nonsalivary tumors, especially in small biopsy specimens. While MYB fluorescence in situ hybridization (FISH) frequently is used to confirm the diagnosis of AdCC, the pathognomonic MYB-NFIB fusion is only present in 40% to 70% of cases. Likewise, although MYB RNA overexpression is seen in the vast majority of AdCC regardless of translocation status, MYB IHC has shown suboptimal specificity for this diagnosis. In this study, we sought to determine whether a novel chromogenic RNA in situ hybridization (ISH) platform could directly detect MYB RNA overexpression and offer a rapid diagnostic adjunct for AdCC. We performed MYB RNA ISH on 84 cases of AdCC as well as 128 other salivary tumors and 108 basaloid and sinonasal carcinomas that mimic AdCC. MYB RNA ISH was 92% sensitive for AdCC, including 97% of cases with MYB rearrangement and 83% without MYB rearrangement by FISH. It was also 89% specific for AdCC overall, with 95% specificity among other salivary tumors and 81% specificity in basaloid and sinonasal carcinomas. In contrast, MYB IHC was 94% sensitive but just 54% specific for AdCC. Overall, MYB RNA ISH provides superior sensitivity for the diagnosis of AdCC compared with MYB FISH and superior specificity compared with MYB IHC. This assay could provide a useful tool for rapidly confirming the diagnosis of AdCC in formalin-fixed, paraffin-embedded specimens.

Treatment outcome and pattern of recurrence of sinonasal squamous cell carcinoma with EGFR-mutation and human papillomavirus

The objective of our study was to clarify the clinical features of EGFR-mutated sinonasal squamous cell carcinoma (SNSCC) and human papilloma virus (HPV)-related SNSCC. Patients with SNSCC treated from April 2008 to June 2019 at our institution were retrospectively reviewed. We examined EGFR mutation and HPV status for all patients. Main outcomes were overall survival, recurrence, and outcome of each treatment modality. A total of 85 patients with SNSCC were enrolled in this study. EGFR mutations and HPV DNA were detected in 24 (28%) and 7 (8%) patients, respectively. Patients with EGFR-mutated SNSCC showed a worse overall survival (OS) than those with EGFR wild-type in the multivariate analysis (p = 0.037). No death was observed in HPV-positive SNSCC. The cumulative incidence of local recurrence was significantly higher in EGFR mutant than EGFR wild-type tumors (p = 0.03). In patients with EGFR mutations, treatment with induction chemotherapy significantly improved OS (p = 0.01). EGFR-mutated SNSCC have a high-risk feature for recurrence and requires intensive attention for treatment and observation. A new treatment approach, such as EGFR tyrosine kinase inhibitors, may be needed.

Primary Pituitary Adenoid Cystic Carcinoma: A Rare Salivary Gland-Like Tumor in the Sella

Adenoid cystic carcinoma (ACC) is a tumor of the exocrine glands that originates primarily from the minor and major salivary glands, nasopharynx, and lacrimal glands. ACC grows slowly but is locally aggressive and prone to recurrence. It is uncommon for ACCs to develop in the pituitary gland as a primary tumor. We present a case of primary pituitary ACC extending to the sphenoid sinus resembling an invasive adenoma in a 71-year-old woman with a history of nasal epistaxis. We reviewed other reported cases of pituitary ACCs with retrospective validation of whether the tumor was primary or not. The intrasellar tumor exhibited MYB rearrangement with enlargement and destruction of the sella turcica and dural tears toward the sphenoid sinus, which would be consistent for a tumor originating from the pituitary gland. Including our case, only four intrasellar and one suprasellar ACC have been confirmed as primary tumors. All intrasellar ACCs had the characteristic of some form of invasion of neighboring structures with evidence of hyperprolactinemia. ACC could develop in the pituitary gland as a form of salivary gland-like tumor derived from the ectopic salivary gland rests. ACCs rarely arise from the pituitary gland; however, the accurate determination of primary occurrence is difficult because of the invasive nature of these tumors, and the anatomical relationship with the sphenoid sinus and the cavernous sinus. Excessive bleeding from the tumor or unexpected internal carotid artery injury should be avoided during surgery for primary and secondary pituitary ACC.

Human Papillomavirus in Sinonasal Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Simple Summary

The causative role of human papillomavirus (HPV) in sinonasal squamous cell carcinoma (SNSCC) remains unclear and is hindered by small studies using variable HPV detection techniques. This meta-analysis aims to provide an updated overview of HPV prevalence in SNSCC stratified by detection method, anatomic subsite, and geographic region. From 60 eligible studies, an overall HPV prevalence was estimated at 26%. When stratified by detection method, HPV prevalence was lower when using multiple substrate testing compared to single substrate testing. Anatomic subsite HPV prevalence was higher in subsites with high exposure to secretion flow compared to low exposure subsites. HPV prevalence in SNSCC followed the global distribution of HPV+ oropharyngeal squamous cell carcinoma. Taken together, this meta-analysis further supports a role for HPV in a subset of SNSCCs.

Abstract

Human papillomavirus (HPV) drives tumorigenesis in a subset of oropharyngeal squamous cell carcinomas (OPSCC) and is increasing in prevalence across the world. Mounting evidence suggests HPV is also involved in a subset of sinonasal squamous cell carcinomas (SNSCC), yet small sample sizes and variability of HPV detection techniques in existing literature hinder definitive conclusions. A systematic review was performed by searching literature through March 29th 2020 using PubMed, Embase, and Web of Science Core Collection databases. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed by two authors independently. A meta-analysis was performed using the random-effects model. Sixty studies (n = 1449) were eligible for statistical analysis estimating an overall HPV prevalence of 25.5% (95% CI 20.7–31.0). When stratified by HPV detection method, prevalence with multiple substrate testing (20.5%, 95% CI 14.5–28.2) was lower than with single substrate testing (31.7%, 95% CI 23.6–41.1), highest in high-exposure anatomic subsites (nasal cavity and ethmoids) (37.6%, 95% CI 26.5–50.2) vs. low-exposure (15.1%, 95% CI 7.3–28.6) and highest in high HPV+ OPSCC prevalence geographic regions (North America) (30.9%, 95% CI 21.9–41.5) vs. low (Africa) (13.1, 95% CI 6.5–24.5)). While small sample sizes and variability in data cloud firm conclusions, here, we provide a new reference point prevalence for HPV in SNSCC along with orthogonal data supporting a causative role for virally driven tumorigenesis, including that HPV is more commonly found in sinonasal subsites with increased exposure to refluxed oropharyngeal secretions and in geographic regions where HPV+ OPSCC is more prevalent.

CYLD-mutant cylindroma-like basaloid carcinoma of the anus: a genetically and morphologically distinct class of HPV-related anal carcinoma

Rare reports of anal carcinoma (AC) describe histologic resemblance to cutaneous cylindroma, but mutations in the tumor suppressor CYLD, the gene responsible for familial and sporadic cylindromas, have not been systematically investigated in AC. Here, we investigate CYLD-mutant AC, focusing on molecular correlates of distinct histopathology. Comprehensive genomic profiling (hybrid-capture-based DNA sequencing) was performed on 574 ACs, of which 75 unique cases (13%) harbored a CYLD mutation. Clinical data, pathology reports, and histopathology were reviewed for each CYLD-mutant case. The spectrum of CYLD mutations included truncating (n = 50; 67%), homozygous deletion (n = 10; 13%), missense (n = 16; 21%), and splice-site (n = 3; 4%) events. Compared with CYLD-wildtype AC (n = 499), CYLD-mutant ACs were significantly enriched for females (88% vs. 67%, p = 0.0001), slightly younger (median age 59 vs. 61 years, p = 0.047), and included near-universal detection of high-risk HPV sequences (97% vs. 88%, p = 0.014), predominantly HPV16 (96%). The CYLD-mutant cohort also showed significantly lower tumor mutational burden (TMB; median 2.6 vs. 5.2 mut/Mb, p < 0.00001) and less frequent alterations in PIK3CA (13% vs. 31%, p = 0.0015). On histopathologic examination, 73% of CYLD-mutant AC (55/75 cases) showed a striking cylindroma-like histomorphology, composed of aggregates of basaloid cells surrounded by thickened basement membranes and containing characteristic hyaline globules, while only 8% of CYLD-wildtype tumors (n = 34/409) contained cylindroma-like hyaline globules (p < 0.0001). CYLD-mutant carcinomas with cylindroma-like histomorphology (n = 55) showed significantly lower TMB compared with CYLD-mutant cases showing basaloid histology without the distinctive hyaline globules (n = 14) (median 1.7 vs. 4.4 mut/Mb, p = 0.0058). Only five CYLD-mutant cases (7%) showed nonbasaloid conventional squamous cell carcinoma histology (median TMB = 5.2 mut/Mb), and a single CYLD-mutant case showed transitional cell carcinoma-like histology. Within our cohort of ACs, CYLD mutations characterize a surprisingly large subset (13%), with distinct clinical and genomic features and, predominantly, a striking cylindroma-like histopathology, representing a genotype-phenotype correlation which may assist in classification of AC.

Human papillomavirus genotype distribution in head and neck cancer: Informing developing strategies for cancer prevention, diagnosis, treatment and surveillance

Current clinical practice algorithms for HPV testing make no effort to discern the impact of genotypes for patients with head and neck squamous cell carcinoma (HNSC). Data was collected for all patients with HNSCs that had undergone HPV testing at an academic hospital as part of clinical care (2012-2019). Screening was performed using real-time PCR targeting L1 of low and high-risk HPV types, followed by genotyping of positive cases. Genotype status was correlated with age, site and histologic parameters. Of the 964 patients tested, 68% had HPV-positive cancers. Most arose from the oropharynx (OP) (89%) and sinonasal tract (5%). The most frequent genotype was 16 (84.4%) followed by 35 (5.6%), 33 (4.1%), 18 (2.7%), 45 (1.1%), 69 (0.8%) and others (1.3%). There was an association between genotype (16 vs non-16) and tumor origin (OP vs non-OP) (p < 0.0001). HPV18 was associated with transformation to an aggressive small cell phenotype, but HPV16 was not (22% vs 0%, p < 0.0001). Patients with HPV-non-16 OP carcinomas were older than patients with HPV16 OP carcinomas, but the difference was not significant. HPV genotypes are variable and unevenly distributed across anatomic sites of the head and neck. The association of HPV18 with small cell transformation suggests that variants can track with certain phenotypes in ways that may account for differences in clinical behavior. This study challenges the prevailing assumption of HPV equivalency across all high-risk genotypes in ways that may inform preventive, diagnostic, therapeutic and surveillance strategies.

Sinonasal analogue HPV related breast multiphenotypic carcinoma, a report of a case with the first description in the breast

Background

High grade basal-like breast carcinomas are triple negative, express basal cytokeratins, and are known for the overall poor prognosis and aggressive behavior. HPV related multiphenotypic sino-nasal carcinoma has overlapping histology with basal-like breast carcinomas, but carry the defining feature of association with high risk HPV.

Case presentation

We present a case of a perimenopausal woman with a non-healing ulcerated lesion involving the nipple and breast following a trauma. Biopsy performed showed an HPV-positive basal-like carcinoma with squamous differentiation involving the breast, analogous to multiphenotypic carcinoma previously described in the sinonasal tract.

Conclusion

This is the first report of a case of a high- risk HPV related basal-like carcinoma with squamous differentiation, described in the literature. We highlight the morphology and immunophenotype of this lesion and its recognition when compared to other multiphenotypic lesions of the breast, and suggest that pathologists should consider HPV evaluation when encountering similar basal-like tumors involving the breast.

Human Papillomavirus (HPV)-Related Carcinoma of the Oropharynx with Squamous Cell and Adenoid Cystic Carcinoma-Like Features: Report of a Case

We describe the heretofore unreported case of an HPV-related carcinoma of the palatine tonsil with distinct areas of squamous cell- and adenoid cystic carcinoma-like differentiation in a 54-year old patient. The morphological, immunophenotypic and molecular findings of the tumor are illustrated. We discuss the parallels between the tumor and HPV-related multiphenotypic sinonasal carcinoma (HMSC) which is well-known to exhibit adenoid cystic carcinoma-like features. A review of the literature of high-risk HPV-associated non-squamous carcinomas of the oropharynx is presented.

p16 Immunoexpression in sinonasal and nasopharyngeal adenoid cystic carcinomas: a potential pitfall in ruling out HPV-related multiphenotypic sinonasal carcinoma

AIMS

Adenoid cystic carcinoma (AdCC) is frequent in the sinonasal region. The recently described human papilloma virus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) histopathologically resembles solid AdCC, but has a better outcome. Thus, clinical and pathogenetic differences between HMSC and sinonasal AdCC necessitate their distinction. We conducted this study to assess p16 immunoexpression in previously diagnosed AdCC cases, and to identify HMSC cases in p16 immunopositive cases.

METHODS AND RESULTS

Cases diagnosed as sinonasal and nasopharyngeal AdCC were retrieved. Histomorphological features were reviewed. Immunohistochemistry (IHC) for p16 was performed. HPV testing was performed in p16-positive cases by mRNA in-situ hybridisation (mRNA ISH) and polymerase chain reaction (PCR) assay. MYB rearrangement was assessed by fluorescence in-situ hybridisation. One hundred and two AdCC cases were retrieved. Six cases (5.9%) showed diffuse p16 positivity. HPV mRNA ISH and PCR were negative in p16-positive cases. Two cases showed MYB rearrangement. p16-positive cases were composed of basaloid cells demonstrating a cribriform pattern, at least focally. The predominant pattern was cribriform in three and solid in three cases. One case showed two distinct components: keratinising squamous cell carcinoma and cribriform AdCC. Other morphological patterns seen were tubular, reticular, epithelial-myoepithelial carcinoma-like, and glomeruloid, forming a minor component of the tumour area.

CONCLUSIONS

p16 staining alone, even when diffuse and strong, cannot be used as a surrogate for HPV testing to distinguish sinonasal AdCC from HMSC. p16 IHC should be accompanied by more specific methods, such as mRNA ISH, so as not to erroneously diagnose HMSC over sinonasal AdCC, bearing in mind the highly aggressive nature of the latter.

Middle Ear and Temporal Bone Nonkeratinizing Squamous Cell Carcinomas With DEK-AFF2 Fusion: An Emerging Entity

Primary squamous cell carcinomas (SCCs) of the middle ear and temporal bone are rare and usually keratinizing by morphology. Nonkeratinizing, basaloid SCCs arising in this area are exceedingly rare, and, due to the anatomic proximity to the skull base, nasopharynx, and nasal sinuses, the differential diagnosis is broad. Most tumors with squamous differentiation arising in these subsites are either viral-induced (human papillomavirus/Epstein-Barr virus) or rarely may have specific molecular alterations (BRD4-NUT, EWSR1-FLI translocations). Occasional tumors are negative for these findings, and their pathogenesis is unknown. A recently discovered DEK-AFF2 fusion was clinically detected in a series of 2 cases known to the authors. This fusion has been previously reported in the literature in a patient with a base of skull tumor who was an exceptional responder to programmed cell death protein 1 inhibitor therapy. We examine here the histomorphologic and molecular findings of 2 additional cases of an emerging entity. Two male patients were identified. Each had a primary middle ear/temporal bone mass with locally advanced disease. The histology was reviewed, and immunohistochemistry was performed. RNA-based next-generation sequencing was performed for clinical detection of diagnostic or actionable fusions. Both patients had basaloid/nonkeratinizing tumors on biopsy. They were positive for markers of squamous differentiation (HMWK, CK5, and p40). By RNA sequencing, they demonstrated the presence of a DEK-AFF2 fusion and were negative for EWSR1 and NUT translocations. The DEK-AFF2 fusion may define a novel diagnostic category of middle ear and temporal bone nonkeratinizing/basaloid SCCs. This fusion also may represent a potential avenue for immunotherapy in these patients. Further studies are needed to fully explore whether this fusion defines a location-specific clinicopathologic entity.

Sinonasal Squamous Cell Carcinoma: Etiology, Pathogenesis, and the Role of Human Papilloma Virus

PURPOSE OF REVIEW

Sinonasal squamous cell carcinoma (SNSCC) is a rare disease with considerable histologic diversity. Currently, there is a poor understanding of the etiology and pathogenesis of SNSCC. Here, we review recent literature to summarize what is known regarding (1) the etiology of SNSCC, (2) the role of Human Papilloma Virus (HPV) in SNSCC, and (2) the molecular underpinnings of SNSCC.

RECENT FINDINGS

1. High risk HPVappears to play a role in the pathogenesis of a subset of SNSCCs. SNSCCs with high risk HPV have improved survival compared with those without HPV and occur in patients who are younger, similar to HPV mediated oropharyngeal cancer. 2. A subset of inverted papillomas have transcriptionally active low-risk HPV and have a higher risk of transformation, while low risk HPV negative inverted papillomas frequently have EGFR mutations.

SUMMARY

SNSCC is a diverse disease with likely multiple etiologies including carcinogen, irritant exposure, and HPV. While not definitively proven, evidence supports a role for high-risk HPV in a subset of SNSCC, and low-risk HPV in a subset of inverted papillomas which transform to SNSCC. In-depth molecular and genomic studies are needed in SNSCC to better understand the genomic underpinnings and oncogenic drivers.

A subset of sinonasal undifferentiated carcinoma is associated with transcriptionally active high-risk human papillomavirus by in situ hybridization: a clinical and pathologic analysis

Sinonasal undifferentiated carcinoma (SNUC) is an aggressive malignancy with a poor prognosis, and pathologically, it is a diagnosis of exclusion. Rendering this diagnosis can be challenging in practice because of the large number of diverse entities in the differential diagnosis. We encountered an index case of a sinonasal carcinoma otherwise diagnosable as SNUC which, on further investigation, demonstrated strong and diffuse P16 expression, as well as diffuse expression of high-risk human papillomavirus (hrHPV) RNA by in situ hybridization (ISH). We therefore hypothesized that a subset of cases previously diagnosed as SNUC may in fact harbor transcriptionally active hrHPV. We further investigated a cohort of 25 SNUC cases in our pathology archives and performed ISH for hrHPV RNA on cases that demonstrated >70% nuclear and cytoplasmic P16 expression, criteria which, in other anatomic sites, correlates strongly with the presence of hrHPV. Twelve of 25 SNUC cases were P16 positive, and of these, 5 were positive for hrHPV by ISH. Thus, 20% of all SNUC cases in this cohort harbored transcriptionally active hrHPV. Herein, we report a clinical and pathologic analysis of these cases, including differential diagnostic considerations and comparison of their clinical behavior with SNUC cases that are negative for hrHPV by ISH.

Adenoid cystic carcinoma of the Bartholin gland is not HPV-related: A case report and review of literature

Adenoid cystic carcinoma (ACC) of the Bartholin gland is a rare gynaecological entity. Despite its slow growth and inconspicuous presentation, vulvar ACC has a propensity for perineural invasion and is therefore associated with high local recurrence rates. We report a case of vulvar ACC in a 61-year-old woman with a prolonged swelling of the Bartholin gland. This patient presented with pulmonary metastases at the moment of histological diagnosis. The vulvar and the pulmonary lesions showed identical histology. Despite a history of human papilloma virus (HPV)-related usual type vulvar intra-epithelial neoplasia and cervical squamous cell carcinoma, the vulvar ACC was negative for both p16 immunohistochemistry and HPV-DNA. We conclude that HPV is not involved in the pathogenesis of pure ACC of the Bartholin gland. Additionally, we advocate a low threshold for performing biopsies of vulvar swellings in women aged >40 years, to rule out malignancy and to prevent diagnostic delays.

Clinical management of emerging sinonasal malignancies

Several emerging sinonasal malignancies have recently been described in the pathology literature. Although not all distinctly classified by the World Health Organization, these rare tumors present a management challenge to surgeons and oncologists. While prior studies have summarized histologic details, a clinically focused review is currently lacking in the literature. This review describes the presentation, histopathology, imaging, treatment, and prognosis of newly described or recently evolving sinonasal malignancies while highlighting the distinguishing features of these entities. It includes teratocarcinosarcoma, human papillomavirus-related multiphenotypic carcinoma, biphenotypic sinonasal sarcoma, sinonasal renal cell-like adenocarcinoma, NUT-midline carcinoma, squamous cell carcinoma associated with inverted papilloma, sinonasal undifferentiated carcinoma, and INI-1-deficient sinonasal carcinoma. By describing the diagnosis, treatment, and prognosis of these recently defined entities, this clinical review aims to help guide oncologists in the clinical management of these patients.

High-risk human papillomavirus-mediated adenocarcinoma of palatine tonsil

We describe the case of a human papillomavirus-mediated adenocarcinoma of palatine tonsil in a 51-year-old male. Histologically, the tumor exhibited a predominantly cribriform and tubular (glandular) growth of cuboidal and columnar cells with moderate amount of pale eosinophilic cytoplasm and oval or spindled nuclei with finely dispersed or coarse chromatin and small to medium-sized nucleoli. Foci of nuclear anaplasia and multinucleation, numerous mitotic figures, and necrosis (individual-cell and confluent) were seen. No squamous differentiation was identified. The tumor cells showed strong expression of CK7, p16 and HPV E6/E7 mRNA transcripts, and were negative for p40, CK5/6, AR, synaptophysin and chromogranin. Next generation sequencing showed 3 variants of unknown significance: FGF3 p.(R44fs); NF1 p.(S749 L) and POLE p. (S1506 L) with variant allele frequencies of 37 %; 20 %, and 17 % respectively. Chromosomal microarray analysis using single nucleotide polymorphism microarray (OncoScan) assay showed whole chromosomal gains of chromosomes 8 and 19, whole chromosomal losses of chromosomes 2 and 16, as well as segmental gains of chromosomes 3q25.31q29 (encompassing the PIK3CA gene), 17q21.31q25.3, 20p13q13.33, Xq28, and segmental losses of chromosomes 1q32.2, 6p25.1p21.1, 11q23.1q24.1, 12p11.22, 12p11.22, 14q24.1q32.33, 17p13.3q21.31 (encompassing the TP53 and NF1 genes). The results highlight the need to consider HPV testing in non-squamous cell carcinomas of the oropharynx.

Sinonasal cancer: an overview of the emerging subtypes

BACKGROUND

Advances in immunohistochemistry have spearheaded major developments in our understanding and classification of sinonasal tumours. In the last decade, several new distinct histopathological entities of sinonasal cancer have been characterised.

OBJECTIVES

This review aims to provide a clinical update of the major emerging subtypes for the ENT surgeon and an overview of the management strategies available for this heterogeneous group of pathologies.

CONCLUSION

Although rare, knowledge of sinonasal neoplasm subtypes has implications for prognosis, treatment strategies and the development of novel therapeutic targets.

HPV-Related Multiphenotypic Sinonasal Carcinoma: A Case Report and Literature Review

OBJECTIVES

Human papilloma virus-related multi phenotypic sinonasal carcinoma (HMSC), a recently characterized sinonasal malignancy, is discussed including histology, clinical presentation, and treatment outcomes.

STUDY DESIGN

Case report with literature review.

METHODS

A case of HMSC is reported, as well as a retrospective review of all cases of HMSC reported in the English literature from January 2000 through May 2018 in the MEDLINE, EMBASE, and Scopus databases. Case data from selected articles was pooled along with the presented case and analyzed.

RESULTS

Including the present case report, a total of 57 cases of HMSC were identified through literature review. Of the 42 cases with staging information, 25 (60%) presented as early-stage disease (T1/T2). No nodal metastasis or disease-specific mortalities were reported. Among the 44 cases with posttreatment follow-up data, 16 cases (36.4%) developed local recurrence. The majority of recurrences occurred 24 to 60 months posttreatment, although reports of recurrence 10 and 29 years posttreatment exist. Local recurrence occurred in 40% and 60% of patients with perineural invasion and bone invasion, respectively. Patients who developed local recurrence had a longer disease-free interval when treated with adjuvant radiotherapy, which approached statistical significance.

CONCLUSIONS

HMSC is a distinct entity with paradoxically aggressive morphology paired with an indolent clinical course characterized by high rates of local recurrence but no reported disease-specific mortalities to date. Surgery with or without adjuvant radiotherapy is the most common treatment modality, and adjuvant radiotherapy may be associated with an increased disease-free interval among patients with local recurrence.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:106-110, 2021.

P16 and human papillomavirus in sinonasal squamous cell carcinoma

Human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (SCC) is a well-known cause and prognostic indicator, and the utility of p16 as a surrogate marker for HPV status has been established. P16 and its relationship with HPV have not been defined in sinonasal malignancy nor has a link with outcomes been established. Patients with sinonasal SCC from 2011 to 2017 were identified from our pathology database. P16 immunohistochemistry and HPV RNA in situ hybridization were performed on tissue specimens. Forty-seven patients were included. Disease-free survival for p16+ patients was significantly higher than p16- patients (P = .043). Fewer HPV+ patients died (P = .052) or experienced recurrence (P = .0437). Odds ratio between p16 and HPV status was 14.19 (95% CI: 1.72, 442.03). Our findings demonstrate improved survival in both the p16+ and HPV+ groups and a positive association between p16 and HPV. There may be similar potential for modifying classification for HPV+ sinonasal SCC.

Sinonasal Undifferentiated Carcinoma (SNUC): From an Entity to Morphologic Pattern and Back Again-A Historical Perspective

Since the first description of sinonasal undifferentiated carcinoma (SNUC) as a distinctive highly aggressive sinonasal neoplasm with probable origin from the sinonasal mucosa (Schneiderian epithelium), SNUC has been the subject of ongoing study and controversy. In particular, the SNUC category gradually became a "wastebasket" for any undifferentiated or unclassifiable sinonasal malignancy of definite or probable epithelial origin. However, with the availability of more specific and sensitive immunohistochemical antibodies and increasing implementation of novel genetic tools, the historical SNUC category became the subject of progressive subdivision leading to recognition of specific genetically defined, reproducible subtypes. These recently recognized entities are characterized by distinctive genetic aberrations including NUTM1-rearranged carcinoma (NUT carcinoma) and carcinomas associated with inactivation of different members of the SWI/SNF chromatin-remodeling gene complex such as SMARCB1-deficient and less frequently SMARCA4-deficient carcinoma. The ring became almost closed, with recent studies highlighting frequent oncogenic IDH2 mutations in the vast majority of histologically defined SNUCs, with a frequency of 82%. A review of these cases suggests the possibility that "true SNUC" probably represents a distinctive neoplastic disease entity, morphologically, phenotypically, and genetically. This review addresses this topic from a historical perspective, with a focus on recently recognized genetically defined subsets within the SNUC spectrum.

Human papilloma virus related squamous cell carcinomas of the head and neck: diagnosis, clinical implications and detection of HPV

High-risk human papillomavirus (HPV) positive squamous cell carcinoma (SCC) of the head and neck is reported most commonly in the oropharynx but can also uncommonly be found in other sites such as the anterior oral cavity and sinonasal tract. While HPV positive oropharyngeal squamous cell carcinoma (HPV-OPSCC) has been shown to have a more favourable prognosis than conventional smoking- and alcohol-related anterior oral cavity squamous cell carcinoma (OSCC), HPV positive SCC arising elsewhere in the head and neck region does not carry the same favourable prognosis. HPV-OPSCC often tends to present with large cystic metastases in the cervical lymph nodes, with a clinically and radiologically occult primary. Correct diagnosis of the initial biopsy/cytology specimen is critical for directing further investigations and management. In recognition of its distinct biological behaviour, the 8th edition of the American Joint Commission on Cancer (AJCC 8) has proposed a separate clinical and pathological staging system for HPV-OPSCC compared to that for a conventional primary OSCC or neck metastasis of similar size. The new AJCC staging does not apply to other HPV positive SCC of the head and neck. This review examines the current biology of HPV positive SCC, focusing on HPV-OPSCC. The value and pitfalls of current detection methods of HPV are discussed with an emphasis on the role of the pathologist in the diagnosis and management of HPV positive SCC of the head and neck.

Human Papillomavirus Related Multiphenotypic Sinonasal Carcinoma: Report of a Case with Early and Progressive Metastatic Disease

Introduction  Human papillomavirus (HPV) related multiphenotypic sinonasal carcinoma (HMSC) is a newly described entity. The prognosis of this neoplasm is not well understood, but cases often demonstrate high-grade features and paradoxically indolent behavior.

Case Report  We present the case of a 65-year-old man referred with unilateral nasal congestion and epistaxis. Nasal endoscopy and imaging revealed an expansile mass filling the left nasal cavity. The patient underwent endoscopic-assisted medial maxillectomy, with complete resection and negative margins. Pathology revealed a basaloid tumor consisting of solid nests with multiple foci of cribriform architecture, with positivity for high-risk HPV, thus supporting the diagnosis of HMSC. Postoperatively, the patient received 66.6-Gy adjuvant three-dimensional proton therapy. Twenty-three months after surgical resection, he developed enlarging pulmonary nodules with biopsy features consistent with the primary sinonasal tumor. He was treated with three cycles of chemotherapy and eight cycles of immunotherapy, progressing on both therapies. He remains on palliative chemotherapy.

Conclusion  Here, we present a case of HMSC with early and progressive distant metastasis. We aim to add to an understanding of the behavior of this entity. Although this neoplasm may typically be indolent, further classification of high-risk features is necessary to identify rare aggressive cases.

Sinonasal Papillomas and Carcinomas: A Contemporary Update With Review of an Emerging Molecular Classification

Context.—

Sinonasal papillomas and carcinomas are uncommon head and neck neoplasms that comprise a broad clinicopathologic and morphologic spectrum, and thus frequently represent a diagnostic challenge for surgical pathologists. Recent molecular interrogation of these tumors has delineated a number of recurrent alterations that correspond to distinct entities with potential diagnostic and/or therapeutic clinical utility.

Objective.—

To summarize the salient clinicopathologic, morphologic, and molecular features of sinonasal papillomas and carcinomas.

Data Sources.—

Review of pertinent literature regarding sinonasal papillomas and sinonasal carcinomas.

Conclusions.—

Despite their relative rarity in many surgical pathology practices, sinonasal papillomas and carcinomas frequently demonstrate characteristic morphologic features that are important for accurate diagnosis. Given our emerging understanding of the molecular basis for these tumors, judicious use of available ancillary tools—including immunohistochemistry and in situ hybridization—may be helpful in subsets of cases, whereas additional molecular testing may be useful for diagnostically challenging and/or clinically aggressive sinonasal tumors.

A clinicopathological and molecular analysis of cervical carcinomas with basaloid features

AIMS

To investigate the relationship between adenoid basal carcinoma (ABC), adenoid cystic carcinoma (ACC) and squamous cell carcinoma (SCC) in the uterine cervix.

METHODS AND RESULTS

We analysed the clinicopathological and molecular features in two pure ABCs, 15 SCCs with ABC-/ACC-like features and seven basaloid SCCs (BSCCs) by chart review, immunohistochemistry, human papillomavirus (HPV) RNA in-situ hybridisation and fluorescence in-situ hybridisation. All patients were alive with no evidence of disease, except for one patient with ACC-like features who died of disease at 18 months post diagnosis. The mixed carcinomas comprised variable SCCs and ABC-/ACC-like components displaying vague transitional zones. All components consistently showed diffuse p16, p63 and SOX2, variable cytokeratin (CK)7 and CK17 and rare Ber-EP4 and MYB expression; there was a substantially lower Ki67 index in pure ABCs and the ABC-like components. The ACC-like components showed no myoepithelial differentiation (SMA, calponin and S100) and MYB gene fusions. CK7, CK17 and Ber-EP4 were characteristically stronger in BSCCs than in the mixed carcinomas (P < 0.01). High-risk HPV (HR-HPV) E6/E7 mRNA was detected in 12 mixed carcinomas and seven BSCCs, but not in pure ABCs. The HR-HPV mRNA expression was higher in the SCC components and BSCCs than in the ABC-like components of mixed carcinomas (P < 0.05).

CONCLUSIONS

The ACC-like components in mixed carcinomas probably represent the morphological mimics of salivary ACCs. ABC-like components may be the potential precursor of the ACC-like and SCC components. HR-HPV oncogenes may play a role in the pathogenesis of SCCs with ABC-/ACC-like features.

HPV-Related Multiphenotypic Sinonasal Carcinoma: Four Cases that Expand the Morpho-Molecular Spectrum and Include Occupational Data

HPV-related multiphenotypic sinonasal carcinoma (HMSC) is a recently described distinct tumor entity of the sinonasal tract associated with high-risk subtypes of human papilloma virus (HPV), predominantly type 33. The biological behavior seems to be less aggressive than the often high-grade, highly proliferative morphology implies; however, recurrences are frequent. Most of the cases present as polypoid tumors within the nasal cavity. Microscopic morphology frequently encompasses adenoid cystic-like features or features reminiscent of other salivary gland tumors. Here, we describe four cases of this rare entity, all observed in women. The polypoid tumors were within the nasal cavity, leading to obstruction, facial pain and epistaxis. The morphology was predominantly basaloid, solid and adenoid cystic-like in two of four cases, one with additional glomeruloid features. Another case showed basaloid tumor cells with prominent mature squamous differentiation and extensive keratinization. A single case showed a predominantly solid and reticular growth pattern. All cases were diffusely positive for p16 (100%), expressed SOX10, LEF-1 and partially S-100, and harbored HPV high-risk types 33, 56 (2×) and 82. No recurrences or metastases were detectable after 3-50 months of follow-up. Of note, three of four patients were nurses/nursing assistant. We expand the morphological spectrum by describing a glomeruloid growth pattern and extensive mature keratinization, and add HPV type 82 to the molecular spectrum. The finding of HMSC among predominantly nurses in our cohort warrants further epidemiological studies in larger cohorts.

Translational genomics of sinonasal cancers

The sinonasal cavities harbor a wide variety of histologically distinct cancers, the majority very aggressive with 5-year survival rates between 30-60% and local recurrence as the main cause of death. This is a complex anatomic area, close to structures such the eyes and the brain, which is of special relevance for surgery and postoperative radiotherapy. The low incidence of these rare tumors hampers accumulation of experience with diagnosis and clinical managment as well as knowledge on recurrent genetic aberrations or testing of new treatment strategies. However, recent years have seen a growing number of publications on genetic aberrations providing data that can aid or fine-tune classification and provide molecular targets for treatment with specific inhibitors. In addition, new sinonasal cancer models are created that enable preclinical testing of candidate inhibitor drugs. With more and more novel targeted therapies being developed, options for personalized treatment of sinonasal cancer patients are now opening up.

Human Papillomavirus-Related Multiphenotypic Sinonasal Carcinoma: A Recent Discovery. A Case Report and Literature Review

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma is a distinct, recently described neoplasm of salivary gland nature that has an unusual microscopic appearance exhibiting multidirectional differentiation. Originally described by Bishop et al. in 2012, this distinct form of head and neck cancer is a very rare entity that few pathologists have encountered in practice, and only 50 cases have been reported in the literature. It usually presents as a large, destructive mass confined to the nasal cavity or paranasal sinuses, and is always associated with high-risk HPV infection. Although histologically it often resembles adenoid cystic carcinoma, this neoplasm also consistently exhibits features of myoepithelial, ductal and squamous differentiation. Newly recognized characteristics have recently been described that include bizarre pleomorphism, sarcomatoid transformation, and heterologous cartilaginous differentiation. These unique features have continued to expand the morphologic spectrum of this neoplasm and justify the recent change in its nomenclature from "HPV-related carcinoma with adenoid cystic-like features" to "HPV-related multiphenotypic sinonasal carcinoma (HMSC)". In 2017, "HPV-related carcinoma with adenoid cystic like features" was included as a provisional tumor type by the World Health Organization Classification of Head and Neck Tumors. Despite the presence of high-grade histologic characteristics such as necrosis and brisk mitotic activity, and a tendency for recurrence, HMSC demonstrates indolent clinical behavior and carries a good prognosis.