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 Testing in Head and Neck Carcinomas: Guideline Update

CONTEXT.—

In 2018, an evidence-based guideline was published by the College of American Pathologists to develop recommendations for the testing, application, interpretation, and reporting of high-risk human papillomavirus and surrogate marker tests in head and neck carcinomas. Substantial new evidence has prompted a review, including data on human papillomavirus (HPV) in nonoropharyngeal anatomic sites, HPV global rates, p16 immunohistochemistry, and HPV testing performance in cytology specimens, and performance of p16 immunohistochemistry as a surrogate marker.

OBJECTIVE.—

To assess research published since the release of the original 2018 guideline and to update evidence-based recommendations for HPV testing in head and neck carcinomas.

DESIGN.—

The College of American Pathologists convened a panel of experts to update the guideline following the standards established by the National Academy of Medicine for developing trustworthy clinical practice guidelines. The expert panel defined the key questions and performed a systematic review of the literature. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, recommendations were updated on the basis of available evidence, certainty of that evidence, and key judgments.

RESULTS.—

Seven strong recommendations, 4 conditional recommendations, and 5 good practice statements are offered in the guideline update.

CONCLUSIONS.—

The updated guideline statements provide direction on the nature of HPV testing in various head and neck specimens (including key updates based on new research on sinonasal squamous cell carcinoma) and expanded guidance on specific scenarios and practice settings. The goal is to improve and standardize, where possible, HPV testing across diverse pathology practice settings and different countries.

Microcystic Adnexal Carcinoma (MAC) and Eccrine Cutaneous Mixed Tumor (ECMT): 2 Cases of Rare HPV-independent Vulvar Cutaneous Adnexal Tumors

Microcystic adnexal carcinoma (MAC) and eccrine cutaneous mixed tumor (ECMT) are both cutaneous adnexal tumors that may occur in the vulvar region, but are very rare at this site. Consequently, they may not enter the differential diagnosis of vulvar lesions for gynecologic pathologists in a subspecialized practice setting. Here we report a case of MAC and a case of ECMT recently diagnosed at our institution and underscore key histologic and immunophenotypic features of each lesion that can assist in their correct identification. Both MAC and ECMT have a tubular to corded pattern of lesional cells within a desmoplastic to chondromyxoid stroma. However, MAC shows true eccrine sweat duct differentiation, characterized by 2 SOX10 negative cell layers, including an outer p63+/p40+/EMA- basal cell layer and an inner p63-/p40-/EMA+ ductal layer. The main differential diagnostic considerations for vulvar MAC include other cutaneous adnexal tumors with true eccrine sweat duct differentiation, namely syringoma and squamoid eccrine ductal carcinoma (SEDC). Conversely, ECMT is characterized by a single SOX10+ cell population without immunoreactivity for p63 or p40. The main differential diagnostic considerations for ECMT include the apocrine variant of cutaneous mixed tumor (ACMT)-the cutaneous analog of salivary gland pleomorphic adenoma-and other SOX10+ salivary gland-type neoplasms. Unlike the recently described vulvar analog of HPV-associated multiphenotypic sinonasal carcinoma, neither MAC nor ECMT are HPV-associated and both are therefore p16 negative. In summary, we report one case each of vulvar MAC and ECMT and discuss the key histologic features and ancillary testing results that can help to differentiate these lesions from their morphologic mimics.

Surgical treatment for uncommon malignancies of the paranasal sinuses and anterior cranial fossa: report of two cases and literature review

Malignant tumors of the nasal and paranasal cavities account for only 3-5% of all head and neck neoplasms. Among these tumors, rare instances of human papillomavirus (HPV)-positive multiphenotypic carcinomas and biphenotypic sarcomas have been documented. Two such cases are reported here, along with the respective treatment approaches. The first involved a 39-year-old male patient diagnosed with HPV-positive multiphenotypic carcinoma. Surgical treatment was performed through a craniofacial and transfacial approach, en bloc resection, and reconstruction of the anterior cranial base with a fascia lata graft and pericranial flap. The second involved a 41-year-old female patient diagnosed with biphenotypic sarcoma. Surgical treatment was performed through centripetal endoscopic tumour resection. In both cases, adjuvant radiotherapy was performed after obtaining the histopathological result and negative margins. Both patients were free of disease during postoperative follow-up. Given the rarity of these cases, there are no established guidelines outlining specific treatments. It is recommended that such tumours are assessed in interdisciplinary committees to determine the optimal treatment options. Typically, this will involve surgical resection via craniofacial and transfacial approaches or endoscopic surgery, depending on the diagnosis, extent of anatomical involvement, and tumour aggressiveness. Additionally, the potential benefits of adjuvant radiotherapy should be evaluated, as it has demonstrated promising outcomes, even in cases with positive margins.

FGFR3::TACC3 fusions in head and neck carcinomas: a study of nine cases highlighting phenotypic heterogeneity, frequent HPV association, and a morphologically distinct subset in favor of a putative entity

The FGFR3::TACC3 fusion has been reported in subsets of diverse cancers including urothelial and squamous cell carcinomas (SCC). However, the morphology of FGFR3::TACC3-positive head and neck carcinomas has not been well studied and it is unclear if this fusion represents a random event, or if it might characterize a morphologically distinct tumor type. We describe nine FGFR3::TACC3 fusion-positive head and neck carcinomas affecting six males and three females aged 38 to 89 years (median, 59). The tumors originated in the sinonasal tract (n = 4), parotid gland (n = 2), and one case each in the oropharynx, submandibular gland, and larynx. At last follow-up (9-21 months; median, 11), four patients developed local recurrence and/or distant metastases, two died of disease at 11 and 12 months, one died of other cause, one was alive with disease, and two were disease-free. Three of six tumors harbored high risk oncogenic HPV infection (HPV33, HPV18, one unspecified). Histologically, three tumors revealed non-keratinizing transitional cell-like or non-descript morphology with variable mixed inflammatory infiltrate reminiscent of mucoepidermoid or DEK::AFF2 carcinoma (all were HPV-negative), and three were HPV-associated (all sinonasal) with multiphenotypic (1) and non-intestinal adenocarcinoma (2) pattern, respectively. One salivary gland tumor showed poorly cohesive large epithelioid cells with prominent background inflammation and expressed AR and GATA3, in line with a possible salivary duct carcinoma variant. Two tumors were conventional SCC. Targeted RNA sequencing revealed an in-frame FGFR3::TACC3 fusion in all cases. This series highlights heterogeneity of head and neck carcinomas harboring FGFR3::TACC3 fusions, which segregates into three categories: (1) unclassified HPV-negative category, morphologically distinct from SCC and other entities; (2) heterogeneous group of HPV-associated carcinomas; and (3) conventional SCC. A driver role of the FGFR3::TACC3 fusion in the first category (as a potential distinct entity) remains to be further studied. In the light of available FGFR-targeting therapies, delineation of these tumors and enhanced recognition is recommended.

Sinonasal malignancy: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

•The CPG provides key recommendations and algorithms for managing SMs, excluding mucosal melanoma and soft-tissue sarcomas. •The guideline covers diagnosis, staging, risk assessment, treatment and disease monitoring. •Technological advancements in treatment with RT are discussed with a special focus on particle therapy. •Surgical indications for open and transnasal endoscopic surgery are provided. •Neoadjuvant chemotherapy in high-grade, locally advanced SMs helps to select subjects for conservative treatments.

Unlocking the Enigma of Human Papillomavirus (HPV)-Related Multi-phenotypic Sinonasal Carcinoma: A Case With Aggressive Morphology but a Favourable Prognosis

Human papillomavirus (HPV) is a well-known established causative agent for head and neck carcinomas, most commonly in the oropharynx. The sinonasal tract is increasingly recognised as a notable site for HPV-related carcinoma, with evidence suggesting a meaningful association with high-risk HPV. The patient is a 44-year-old female, who presented with a nasal septal growth. Initial biopsy was reported as poorly differentiated carcinoma. Subsequent excision showed malignant neoplasm with varied histomorphological patterns with areas resembling poorly differentiated carcinoma, some areas showing adenoid cystic-like features and focal pericytomatous pattern. Immunohistochemically, the neoplastic cells were diffusely positive for Pancytokeratin and p16 with a patchy expression of p63, p40, SMA, and C-KIT. The proliferation index as assessed by Ki-67 was around 35%. HPV testing by RT-PCR was positive, and the HPV-33 genotype was detected. With the given findings, a diagnosis of HPV-related multi-phenotypic sinonasal carcinoma was rendered. HPV-related multi-phenotypic sinonasal carcinoma (HMSC) shows an indolent clinical course despite an aggressive morphology. Surgery with or without radiotherapy is the recommended treatment of choice.

Human Papillomavirus-Associated Multiphenotypic Carcinoma: First Description of a Vulval Case

Human papillomavirus (HPV)-associated multiphenotypic sinonasal carcinoma is a rare and recently described epithelial neoplasm exhibiting myoepithelial differentiation and morphological overlap with salivary gland neoplasms, especially adenoid cystic carcinoma; it is commonly associated with HPV, especially type 33. It has mainly been reported in the nasal cavity and paranasal sinuses with a single case reported in the breast. Herein, we report the first vulval example in a 47-year-old patient who presented with a large craggy mass in the region of the Bartholin gland. The histologic features were of a high-grade carcinoma composed of basaloid cells arranged in sheets and nests, with occasional ductal formations, surrounded by densely hyalinised basement membrane-type material. There was diffuse block-type immunoreactivity with p16 and HPV genotyping revealed high-risk HPV type 16. In reporting this case, we highlight the propensity for "salivary gland-type" neoplasms to arise in the vulva, especially in the Bartholin gland, and stress that pathologists should consider salivary-type neoplasms when faced with a morphologically unusual vulval tumor.

Sinonasal Adenocarcinomas: An Update

Among sinonasal malignancies, adenocarcinomas account for the second most common entity after squamous cell carcinoma. They span a wide spectrum of neoplasms with heterogeneous features including intestinal-type adenocarcinoma (ITAC), non-intestinal-type adenocarcinomas (non-ITACs), and salivary-type adenocarcinomas. ITAC basically mirrors the histopathological aspects of gastrointestinal counterparts, showing variable tubulo-papillary, colonic, and mixed patterns with mucin production in 20% to 25% of cases. By contrast, non-ITACs do not show any differentiation toward intestinal or salivary phenotype, and they mainly represent a diagnosis of exclusion lacking a proper histopathological and molecular definition.

Human Papillomavirus in Sinonasal Tract Tumors-Another Head and Neck "Hot Spot" for Prognostically Favorable Viral Disease

The sinonasal tract, while an uncommon site of SCC overall, is another "hot spot" for transcriptionally-active high-risk HPV-associated tumors. The accumulating data show that, across the world, the rate of HPV-associated SCC here is approximately 15% and, in the United States, closer to 30%. Patients have lower disease recurrence and better survival than HPV-independent SCC patients. Low-risk HPV also causes a smaller subset of sinonasal SCC, mostly through exophytic and inverted papillomas that transform into SCC. It is not known if these patients have better survival than patients with low-risk HPV-negative SCC. This article reviews the latest data on HPV in sinonasal tumors.

DEK::AFF2 Carcinoma of the Sinonasal Tract and Skull Base: A Comprehensive Review

DEK::AFF2 carcinoma is an emerging entity of the sinonasal tract and skull base, commonly exhibiting exophytic and endophytic papillary growth, complex anastomosing trabeculae, monotonous cytomorphology, acantholytic change, and tumor-infiltrating neutrophils. A subset displays overt infiltration and high-grade features akin to non-keratinizing squamous cell carcinoma. Glandular differentiation may also be rarely present. The tumor shows frequent local recurrence and occasional distant metastasis. An accurate diagnosis requires the recognition of these key histologic features, followed by molecular confirmation. Recently, AFF2 immunohistochemistry has been demonstrated to be a sensitive and specific ancillary marker. This comprehensive review summarizes the current understanding of DEK::AFF2 carcinoma.

Why HPV16? Why, now, HPV42? How the discovery of HPV42 in rare cancers provides an opportunity to challenge our understanding about the transition between health and disease for common members of the healthy microbiota

In 2022, a bioinformatic, agnostic approach identified HPV42 as causative agent of a rare cancer, later confirmed experimentally. This unexpected association offers an opportunity to reconsider our understanding about papillomavirus infections and cancers. We have expanded our knowledge about the diversity of papillomaviruses and the diseases they cause. Yet, we still lack answers to fundamental questions, such as what makes HPV16 different from the closely related HPV31 or HPV33; or why the very divergent HPV13 and HPV32 cause focal epithelial hyperplasia, while HPV6 or HPV42 do not, despite their evolutionary relatedness. Certain members of the healthy skin microbiota are associated to rare clinical conditions. We propose that a focus on cellular phenotypes, most often transient and influenced by intrinsic and extrinsic factors, may help understand the continuum between health and disease. A conceptual switch is required towards an interpretation of biology as a diversity of states connected by transition probabilities, rather than quasi-deterministic programs. Under this perspective, papillomaviruses may only trigger malignant transformation when specific viral genotypes interact with precise cellular states. Drawing on Canguilhem's concepts of normal and pathological, we suggest that understanding the transition between fluid cellular states can illuminate how commensal-like infections transition from benign to malignant.

Update on Sinonasal Tract Malignancies: Advances in Diagnostic Modalities

CONTEXT.—

Sinonasal tract malignancies are rare cancers with frequent morphologic overlap. Given the similar histologic profiles seen in many of these entities, they often present a diagnostic challenge to the practicing pathologist.

OBJECTIVE.—

To provide a streamlined algorithm using histologic clues, immunohistochemical profiles, and molecular assays to aid in diagnosis of these lesions.

DATA SOURCES.—

Sources were the World Health Organization Tumor Classification, literature review, and institutional experience.

CONCLUSIONS.—

Although many sinonasal tract malignancies show similar histology, distinct immunohistochemical and molecular profiles can help parse out differences, thereby facilitating diagnosis for the pathologist.

Whole exome sequencing of human papillomavirus-related multiphenotypic sinonasal carcinoma: a case report

Human Papillomavirus (HPV) related Multiphenotypic Sinonasal Carcinoma (HMSC) is a rare tumor with features of both atypical squamous cell and adenoid cystic carcinoma, making diagnosis challenging. Approximately 80% of HMSC cases carries HPV type 33 followed by type 35. We present a patient with HMSC. Pathological classification was aided by immunohistochemistry (IHC). The presence of HPV-DNA was tested using PCR and HPV E6/E7 expression by RNA in situ hybridization (RNA ISH). Whole exome sequencing (WES) was used to identify somatic gene mutations and copy number alterations. A 55-year-old male presented with an HMSC in the right nostril. Histological examination showed a solid basaloid subtype with mucinous spaces and ductal structures. IHC showed positive staining for SOX-10, SMA, p40, p63, PanCK, CK8 and MYB. Diffuse positive staining for p16 was observed and PCR and RNA ISH indicated the presence of HPV type 35. The patient was treated with endoscopic surgery and radiotherapy and is currently alive and recurrence-free after 16 months of follow-up. WES revealed 38 somatic sequence variants and several chromosomal regions with copy number alterations, including a copy number gain at 6q23 where MYB is located. EP300, ZNF22, ZNF609 and LRIG3 are some of the genes whose mutations were indicated as probably pathogenic. We did not find mutations predictive for drug response according to the ESMO Scale for Clinical Actionability of Molecular Targets database. This is the first report of WES analysis of an HMSC, in this case associated with HPV type 35. The detected mutation in EP300 and the overexpression of MYB may serve as molecular targets for personalized therapy.

Human Papillomavirus (HPV)-Related Multiphenotypic Sinonasal Carcinoma With Intracranial Extension and Rapid Recurrence: A Case Report

HPV-related multiphenotypic sinonasal carcinoma (HMSC) is a rare malignancy of the nasal cavity or paranasal sinuses that often presents with indolent behavior despite aggressive histologic appearance. Herein, we present an unusual case of a patient with HMSC presenting with rapid local recurrence, highlighting the histopathology and diagnostic and therapeutic strategies surrounding HMSC.

A Case of Human Papillomavirus-Related Multiphenotypic Sinonasal Carcinoma

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is a recently described neoplasm entity that presents only in the sinonasal tract. Histologically, it displays features of both a surface-derived carcinoma and a salivary gland carcinoma, and is associated with high-risk HPV, specifically HPV type 33. Whereas majority of the cases display high-grade histologic features, HMSC paradoxically behaves in a relatively indolent fashion. It is important and meaningful to distinguish HMSC from other histopathologic mimickers as the clinical features and management are distinctive. A 64-year-old woman presented having intermittent left-side epistaxis and progressive nasal obstruction. A well-defined, solitary, friable mass with an irregular surface that easily bled upon contact was found in the posterior part of the left nasal cavity. Endoscopic excision of the tumor which was originated from left nasal septum was done and the tumor was confirmed as HMSC. After surgery, definitive radiotherapy was performed in 28 fractions. HMSC is a histopathological type that has been rarely reported so that we report this case with literature review.

Outcome-oriented clinicopathological reappraisal of sinonasal adenoid cystic carcinoma with broad morphological spectrum and high MYB::NFIB prevalence

Adenoid cystic carcinoma (AdCC) is a salivary gland neoplasm that infrequently appears in the sinonasal region. The aim of this study was to evaluate the outcome and clinicopathological parameters of sinonasal AdCC. A retrospective analysis was conducted on all cases of AdCC affecting the nasal cavity or paranasal sinuses between 2000 and 2018 at the University Hospital Zurich. Tumor material was examined for morphological features and analyzed for molecular alterations. A total of 14 patients were included. Mean age at presentation was 57.7 years. Sequencing revealed MYB::NFIB gene fusion in 11/12 analyzable cases. Poor prognostic factors were solid variant (p < 0.001), histopathological high-grade transformation (p < 0.001), and tumor involvement of the sphenoid sinus (p = 0.02). The median recurrence-free survival (RFS) and OS were 5.2 years and 11.3 years. The RFS rates at 1-, 5-, and 10-year were 100%, 53.8%, and 23.1%. The OS rates at 1-, 5-, and 10- years were 100%, 91.7%, and 62.9%, respectively. In Conclusion, the solid variant (solid portion > 30%), high-grade transformation, and sphenoid sinus involvement are negative prognostic factors for sinonasal AdCC. A high prevalence of MYB::NFIB gene fusion may help to correctly classify diagnostically challenging (e.g. metatypical) cases.

Morphologic Spectrum of HPV-associated Sinonasal Carcinomas

BACKGROUND

High-risk human papillomavirus (HR-HPV) infection has been increasingly recognized as a risk factor for sinonasal tract carcinomas. However the prevalence and prognostic significance of HPV-associated sinonasal carcinomas is not well known due to limited studies and inconsistency in HPV testing modalities in literatures. Morphologically, HPV-associated sinonasal carcinomas encompass a diverse group of tumors. HPV-associated sinonasal adenocarcinoma has not been reported. The purpose of this study was to determine the prevalence, morphologic spectrum and prognostic implication of HPV-associated sinonasal carcinomas.

METHODS

This cohort included 153 sinonasal carcinomas. Tissue microarrays were constructed. P16 immunohistochemistry and HR-HPV E6/7 in-situ Hybridization (ISH) were performed. Carcinomas were deemed HPV-associated based on a positive ISH testing. Clinicopathologic data was collected.

RESULTS

28/153 (18%) sinonasal carcinomas were HPV-associated. HPV-associated carcinomas consisted of 26 (93%) squamous cell carcinomas and variants, 1 (3.5%) HPV-related multiphenotypic sinonasal carcinoma and 1 (3.5%) adenocarcinoma. The HPV-associated adenocarcinoma closely resembled HPV-associated endocervical adenocarcinoma morphologically. HPV-associated carcinomas occurred in 8 (29%) women and 20 (71%) men with a median age of 66 years old. HPV-associated carcinomas were predominantly located at nasal cavity. A trend toward improved overall survival and progression free survival in HPV-associated carcinomas patients was observed, yet without statistical significance.

CONCLUSION

Our study identifies a novel HPV-associated sinonasal adenocarcinoma subtype, highlights the broad morphologic spectrum of HPV-associated sinonasal carcinomas, and supports routine p16 testing during pathology practice regardless of tumor subtype followed by a confirmatory HR-HPV testing. This practice is critical for studying the clinical behavior of HPV-associated sinonasal carcinomas.

Oropharyngeal Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN): A Case Report and Literature Review

Mixed neuroendocrine-nonneuroendocrine (MiNEN) neoplasms in the head and neck are exceptionally rare biphasic tumors with unclear pathogenesis and an aggressive clinical behavior. This is the first reported case of an oropharyngeal MiNEN with the nonneuroendocrine component being an HPV-associated adenocarcinoma. The tumor arose in a 56 year-old male with history of long-term cigarette smoking and was composed of an adenocarcinoma intermixed with a small cell neuroendocrine carcinoma. P16 immunohistochemical stain and HPV16/18 in-situ hybridization were strongly and diffusely expressed in both components.

Molecular patterns and mechanisms of tumorigenesis in HPV-associated and HPV-independent sinonasal squamous cell carcinoma

Mechanisms of tumorigenesis in sinonasal squamous cell carcinoma (SNSCC) remain poorly described due to its rare nature. A subset of SNSCC are associated with the human papillomavirus (HPV); however, it is unknown whether HPV is a driver of HPV-associated SNSCC tumorigenesis or merely a neutral bystander. We hypothesized that performing the first large high-throughput sequencing study of SNSCC would reveal molecular mechanisms of tumorigenesis driving HPV-associated and HPV-independent SNSCC and identify targetable pathways. High-throughput sequencing was performed on 64 patients with HPV-associated and HPV-independent sinonasal carcinomas. Mutation annotation, viral integration, copy number, and pathway-based analyses were performed. Analysis of HPV-associated SNSCC revealed similar mutational patterns observed in HPV-associated cervical and head and neck squamous cell carcinoma, including lack of TP53 mutations and the presence of known hotspot mutations in PI3K and FGFR3. Further similarities included enrichment of APOBEC mutational signature, viral integration at known hotspot locations, and frequent mutations in epigenetic regulators. HPV-associated SNSCC-specific recurrent mutations were also identified including KMT2C , UBXN11 , AP3S1 , MT-ND4 , and MT-ND5 . Mutations in KMT2D and FGFR3 were associated with decreased overall survival. We developed the first known HPV-associated SNSCC cell line and combinatorial small molecule inhibition of YAP/TAZ and PI3K pathways synergistically inhibited tumor cell clonogenicity. In conclusion, HPV-associated SNSCC and HPV-independent SNSCC are driven by molecularly distinct mechanisms of tumorigenesis. Combinatorial blockade of YAP/TAZ and vertical inhibition of the PI3K pathway may be useful in targeting HPV-associated SNSCC whereas targeting MYC and horizontal inhibition of RAS/PI3K pathways for HPV-independent SNSCC.

One Sentence Summary

This study solidifies HPV as a driver of HPV-associated SNSCC tumorigenesis, identifies molecular mechanisms distinguishing HPV-associated and HPV-independent SNSCC, and elucidates YAP/TAZ and PI3K blockade as key targets for HPV-associated SNSCC.

Molecularly defined sinonasal malignancies: an overview with focus on the current WHO classification and recently described provisional entities

Classification of tumors of the head and neck has evolved in recent decades including a widespread application of molecular testing in tumors of the sinonasal tract, salivary glands, and soft tissues with a predilection for the head and neck. The availability of new molecular techniques has allowed for the definition of multiple novel tumor types unique to head and neck sites. Moreover, an expanding spectrum of immunohistochemical markers specific to genetic alterations facilitates rapid identification of diagnostic molecular abnormalities. As such, it is currently possible for head and neck pathologists to benefit from a molecularly defined tumor classification while making diagnoses that are still based largely on histopathology and immunohistochemistry. This review covers the principal molecular alterations in sinonasal malignancies, such as alterations in DEK, AFF2, NUTM1, IDH1-2, and SWI/SNF genes in particular, that are important from a practical standpoint for diagnosis, prognosis, and prediction of response to treatment.

HPV-Related Multiphenotypic Sinonasal Carcinoma: A Clinicoradiological Series of 3 Cases With Full Endoscopic Surgical Outcome

Context: Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC), formerly known as HPV-related carcinoma with adenoid cystic like features, is a rare tumor subtype with unusual correlation between radiological, histopathological, and surgical findings. The shared histological characteristics with other sinonasal tumors make the diagnosis challenging. Optimal surgical and oncological treatments for this rare condition remains to be clearly defined. Methods: The objective of the study was to describe the unique characteristics and endoscopic surgical treatment of this rare tumor. In this retrospective case series, all patients with an HMSC diagnosis treated in our tertiary center were selected. Results: Three HMSC cases were identified, including 2 male and 1 female patients. All cases originated from the posterior nasal cavity. One case presented with a tumor of 8.9 cm × 6.4 cm × 8.7 cm, which is the largest tumor volume described to date. All patients received exclusively endoscopic surgical treatment, followed by adjuvant radiation therapy. No patient showed clinical or radiological sign of disease recurrence, or regional or distant metastasis, with a follow-up ranging from 9 months to 4 years. In 2 cases, initial diagnoses incorrectly suggested adenoid cystic or basaloid squamous cell carcinoma. HPV-DNA testing confirmed the presence of HPV in all cases, with identification of strains 16 and 18. Conclusion and Relevance: HMSC represents a newly identified diagnosis that constitutes a significant challenge for both clinicians and pathologists. It is crucial to acknowledge its indolent clinical course and the apparent contradiction between aggressive radiological features and the noninvasive nature of surgical findings. Skull base surgeons should be aware that, despite these complexities, endoscopic treatment is achievable in the majority of cases. This understanding is essential for the effective management of HMSC.

Validation of the VisionArray® Chip Assay for HPV DNA Testing in Histology Specimens of Oropharyngeal Squamous Cell Carcinoma

BACKGROUND

The detection of human papillomavirus (HPV) has several implications in the diagnostic work-up and management of oropharyngeal squamous cell carcinoma (OPSCC). The choice of HPV detection assay and testing algorithms differ across institutions and vary in cost, detection targets, technical feasibility, and turnaround time. In this study, we aimed to validate the VisionArray® HPV Chip for formalin-fixed and paraffin-embedded (FFPE) samples of OPSCC using the previously applied standard pan-HPV DNA PCR assay as a reference.

METHODS

The validation cohort consisted of FFPE tissue samples from patients previously diagnosed with HPV DNA-positive OPSCC (n = 80), HPV DNA-negative OPSCC (n = 21), and a benign group of tumor samples consisting of Warthin's tumors (n = 20) and branchial cleft cysts of the lateral neck (n = 14). All samples were tested with p16 immunohistochemistry, pan-HPV DNA PCR, and the VisionArray® HPV Chip.

RESULTS

The overall sensitivity and specificity of the VisionArray® HPV Chip assay were 100% [95% CI 95.5%; 100.0%] and 96.3% [95% CI 87.3%; 99.6%] and the positive predictive value and negative predictive value were 97.6% [95% CI 91.5%; 99.7%] and 100% [95% CI 93.2%; 100%], respectively.

CONCLUSIONS

The VisionArray® HPV Chip assay can be recommended for high-risk HPV testing in FFPE tissue samples from OPSCC, providing both a fast and simultaneous genotyping for 41 clinically relevant HPV types.

Evaluation of Some Prognostic Biomarkers in Human Papillomavirus-Related Multiphenotypic Sinonasal Carcinoma

Background

Human papillomavirus (HPV)-related multi phenotypic sinonasal carcinoma (HMSC) is a recently described tumor subtype with an unknown prognosis, often misdiagnosed with other sinonasal carcinomas, and associated with high-risk HPV (HR-HPV). The present study aimed to evaluate the expression of vascular endothelial growth factor (VEGF), Bcl-2-associated X protein (BAX), epidermal growth factor receptors (EGFR), ProExTMC, and human telomerase reverse transcriptase (hTERT) and assess their association with survival and clinicopathological characteristics.

Methods

Between 2017 and 2022, 40 HMSC patients underwent surgical resection at the School of Medicine, Zagazig University Hospitals (Zagazig, Egypt). Tissue samples were examined for the presence of HR-HPV; absence of myeloblastosis (MYB), MYB proto-oncogene like 1 (MYBL1), and nuclear factor I/B (NFIB) fusions and the presence of myoepithelial proteins (calponin, S100, SMA), squamous differentiation markers (p63, p40, calponin), VEGF, BAX, ProExTMC, and hTERT by immunohistochemistry. All patients were followed up for about 54 months until death or the last known survival data. Data were analyzed using the Chi square test and Kaplan-Meier method.

Results

The expression of VEGF, hTERT, and ProExTMC was significantly associated with age, advanced tumor stages, lymph node metastasis, tumor size, mortality, relapse, poor disease-free survival (DFS), and overall survival (OS) (P<0.001). BAX expression was significantly associated with tumor size, age, poor DFS, and relapse (P=0.01, P<0.001, P=0.035, and P=0.002, respectively).

Conclusion

HMSC is strongly associated with HR-HPV. The expression of VEGF, EGFR, BAX, hTERT, and ProExTMC is associated with aggressive malignant behavior, poor survival, and poor prognosis, making them novel prognostic biomarkers for targeted therapeutics in HMSC.

FGFR1/2/3-rearranged carcinoma of the head and neck: expanded histological spectrum crossing path with high-risk HPV in the sinonasal tract

AIMS

Oncogenic FGFR1/2/3 rearrangements are found in various cancers. Reported cases in head and neck (HN) are mainly squamous cell carcinomas (SCCs) with FGFR3::TACC3 fusions, a subset of which also harbour high-risk human papillomavirus (HPV). However, the knowledge of the clinicopathological spectrum of FGFR-rearranged head and neck carcinomas (FHNC) is limited.

METHODS AND RESULTS

A retrospective MSK-fusion clinical sequencing cohort 2016-23 was searched to identify malignant tumours in the HN region harbouring FGFR1/2/3 fusion. FHNC were characterised by histological examination, immunohistochemistry and molecular analysis. Electronic medical records were reviewed. Three FHNC were identified. Two cases (cases 1 and 2) involved sinonasal tract and were high-grade carcinomas with squamous, basaloid, glandular and/or ductal-myoepithelial features. Case 1 arose in a 79-year-old man and harboured FGFR2::KIF1A fusion. Case 2 arose in a 58-year-old man, appeared as HPV-related multiphenotypic sinonasal carcinoma (HMSC), and was positive for FGFR2::TACC2 fusion and concurrent high-risk HPV, non-type 16/18. Case 3 was FGFR3::TACC3 fusion-positive keratinising SCCs arising in the parotid of a 60-year-old man. All three cases presented at stage T4. Clinical follow-up was available in two cases; case 1 remained disease-free for 41 months post-treatment and case 3 died of disease 2 months after the diagnosis.

CONCLUSIONS

FHNC include a morphological spectrum of carcinomas with squamous features and may occur in different HN locations, such as parotid gland and the sinonasal tract. Sinonasal cases can harbour FGFR2 rearrangement with or without associated high-risk HPV. Timely recognition of FHNC could help select patients potentially amenable to targeted therapy with FGFR inhibitors. Further studies are needed (1) to determine if FGFR2 rearranged/HPV-positive sinonasal carcinomas are biologically distinct from HMSC, and (2) to elucidate the biological and clinical significance of FGFR2 rearrangement in the context of high-risk HPV.

Induction chemotherapy response of HPV-related multiphenotypic sinonasal carcinoma: First-ever reported therapeutic outcome and a brief literature review

A 54-year-old male patient complained of nasal obstruction and epistaxis for 2 years, with worsening of the symptoms in the preceding year. Physical examination revealed a friable, irregular mass, with yellowish secretion, in the left nasal fossa. Magnetic resonance imaging revealed an expansive lesion in the left nasal cavity, extending into the nasopharynx, ethmoid, right nasal cavity, and cortical bone of the hard palate. An incisional biopsy was then performed. Morphologically, a cellular malignant proliferation with a solid basaloid appearance admixed with adenoid cystic-like areas was observed. Immunohistochemistry revealed positivity for AE1/AE3, CK7, p63, and calponin, with focal labeling for CD117 and α-SMA. p16 had diffuse cytoplasmic and nuclear positivity. Ki-67 index was >80%. Given the morphological and immunohistochemical aspects, the diagnosis was conclusive for HPV-related multiphenotypic sinonasal carcinoma. The tumor was considered irresectable, and the patient was submitted to induction chemotherapy with docetaxel, cisplatin, and infusional 5-fluorouracil, with significant regression after therapy, followed by chemoradiotherapy with carboplatin, without limiting toxicities. The patient is currently under regular follow-up, with complete clinical and radiological response. To date, there are no reports in the literature of induction chemotherapy use or its complete therapeutic responsiveness related to this lesion. A brief literature review was included with the main epidemiological, clinical, therapeutic, and prognostic aspects regarding the 85 cases reported in the literature, including ours.

Update from the 5th Edition of the WHO Classification of Nasal, Paranasal, and Skull Base Tumors: Imaging Overview with Histopathologic and Genetic Correlation

Sinonasal and skull base tumors are a heterogeneous group of neoplasms with considerable histologic variation and overlapping imaging features. In 2022, the World Health Organization updated the head and neck tumor classification, further emphasizing the importance of molecular data and genetic alterations in sinonasal neoplasms. The changes include the addition of new entities and discussion of emerging entities, as well as changes to the taxonomy and characterization of tumors. The new classification focuses on entities that develop in these sites either exclusively (eg, olfactory neuroblastoma) or most frequently. Another change includes reduction in the number of categories by creating separate category-specific chapters for soft-tissue, hematolymphoid, and neuroectodermal lesions. In this review, we briefly discuss the various categories in the new classification with a more detailed description of the 2 new entities (SWItch/Sucrose Non-Fermentable complex-deficient sinonasal carcinomas and human papillomavirus-related multiphenotypic sinonasal carcinoma). We also highlight the emerging entities including IDH-mutant sinonasal malignancies and DEK-AFF2 carcinoma, presently classified as sinonasal undifferentiated carcinoma and nonkeratinizing squamous cell carcinoma, respectively.

Challenging differential diagnoses in small biopsies from the sinonasal tract

Sinonasal biopsy specimens are a challenging area in anatomic pathology. The small, often fragmented or crushed nature of these biopsies can hinder morphologic assessment. Additionally, many of the tumors in this area are rare and share morphologic, and sometime immunophenotypic similarities. In many cases, immunohistochemistry is helpful if not necessary to reach a specific diagnosis. In other cases, a specific diagnosis is not possible and a differential diagnosis must be given on a biopsy specimen despite access to a well-equipped immunohistochemistry laboratory. This review article groups some of the more challenging entities in the sinonasal region based on morphologic patterns. These include low grade squamoid lesions such as sinonasal (Schneiderian) papilloma and DEK::AFF2 rearranged carcinoma, glandular neoplasms such as intestinal and non-intestinal type sinonasal adenocarcinoma, high-grade carcinomas such as HPV-related multiphenotypic sinonasal carcinoma, NUT carcinoma and SWI/SNF deficient carcinomas, small round blue cell tumors such as teratocarcinosarcoma, neuroendocrine carcinoma and olfactory neuroblastoma, and finally, low grade spindle cell neoplasms such as glomangiopericytoma, biphenotypic sinonasal sarcoma and solitary fibrous tumor.

[Sinonasal neoplasms: Update from the WHO 2022]

The pathology of poorly differentiated sinonasal malignancies has undergone a dynamic evolution during the last decade, resulting in a refined, mostly genetically or etiologically oriented classification of neoplasms in the historical spectrum of sinonasal undifferentiated carcinoma (NUT carcinoma, SWI-/SNF-deficient carcinomas, and others). Moreover, some new entities have been established, while others could be further delineated and better characterized. A highlight of the new classification is the inclusion of SWI/SNF (SMARCB1 or SMARCA4)-deficient carcinomas into a separate category. In addition, carcinomas with DEK::AFF2 fusions have been included as a provisional entity in the spectrum of nonkeratinizing squamous cell carcinoma. This review addresses the major changes in the classification of sinonasal tract neoplasms in the new WHO classification.

Human Papillomavirus-Related Recurrent Multiphenotypic Sinonasal Carcinoma With HPV Genotype 56 Detected by HPV Direct Flow CHIP

Human Papillomavirus-related multiphenotypic sinonasal carcinoma is a rare, and recently described neoplasm, defined by its association with high-risk Human Papillomavirus, which exclusively affects the sinonasal tract and simulates salivary gland tumors. Due to the infrequency of this neoplasm and the lack of knowledge of its pathological characteristics, it is susceptible to diagnostic error. We describe the clinical-radiological findings of a 54-year-old man with multiphenotypic sinonasal carcinoma related to Human Papillomavirus genotype 56. The diagnosis of multiphenotypic sinonasal carcinoma was suspected by light microscopy and was corroborated by immunohistochemistry and polymerase chain reaction (PCR) analysis. The patient was subsequently treated with 63.6 gray radiotherapies. He is currently alive after a follow-up of 20 months, with a recurrence of the disease. In conclusion, multiphenotypic sinonasal carcinoma is an unusual neoplasm, which is not well recognized and can be confused with adenoid cystic carcinoma. However, multiphenotypic sinonasal carcinoma should be included in the differential diagnosis as we encounter sinonasal tumors, which by histology present tubular, cribriform, and solid growth patterns, accompanied by dysplasia or carcinoma in situ in the superficial mucosa. In this case, it is necessary to perform immunohistochemistry for p16INK4A or PCR to confirm the presence of high-risk Human Papilloma Virus, which would confirm the diagnosis.

High-risk HPV Does not Appear to be an Important Risk Factor for Sinonasal Carcinomas in Turkish Population: A Tertiary Center Experience

Background. The sinonasal tract is the second most common site of human papillomavirus (HPV)-related carcinomas in the head and neck. Published data on the association between sinonasal tumors and HPV are quite inconsistent among different regions. Material and methods. We performed high-risk HPV DNA in situ hybridization (ISH) and p16 immunohistochemistry on sinonasal carcinomas diagnosed between 2006 and 2016. Results. Of 105 sinonasal carcinomas, we found only two (2%) HPV-positive cases; both had non-keratinizing morphology and were diffusely positive for p16. By histologic type, HPV DNA positivity rate was 14% in non-keratinizing squamous cell carcinomas, and we did not detect HPV DNA in any other type of sinonasal carcinomas. Thirteen HPV-negative tumors (7 salivary gland carcinomas, 3 sinonasal undifferentiated carcinomas, 2 keratinizing squamous cell carcinomas, and 1 non-keratinizing squamous cell carcinoma) were positive for p16. In nine carcinomas arising from an underlying sinonasal papilloma, p16 and HPV DNA ISH were evaluated in both carcinoma and papilloma areas and all were negative. Follow-up information was available for 104 patients; 46 (44%) were alive and 58 (55%) died of disease. One of the two HPV-positive patients died of the disease; the other was alive at 100 months of follow-up. Conclusions. We detected a much lower percentage of HPV positivity in sinonasal carcinomas when compared to the literature. We believe that our results support various rates of HPV-related carcinomas depending on the geographic and ethnic characteristics.

IDH2 -Mutated Sinonasal Tumors: A Review

INTRODUCTION

Genetic profiling has caused an explosion in the subclassification of sinonasal malignancies. Distinguishing several of these tumor types by histomorphology alone has been quite challenging, and although pathologic classification aims to be as specific as possible, it remains to be seen if this recent move toward tumor speciation bears clinical relevance, most particularly focused on subtyping for the sake of prognostication and treatment. One such recently described cohort, predominantly lumped under the moniker of sinonasal undifferentiated carcinoma (SNUC) is IDH2 -mutated sinonasal carcinoma, a high-grade carcinoma associated with mutations in the isocitrate dehydrogenase-2 ( IDH2 ) gene. A hotspot mutation in the R172 codon has been described in 50% to 80% of the tumors classified as SNUC, large cell neuroendocrine carcinomas, and rarely in cases classified as olfactory neuroblastoma. The use of immunohistochemical and molecular approaches is required to correctly identify this subset of sinonasal tumors, with further study necessary to elucidate their unique pathophysiology, ultimately determining whether a revision is required toward the current therapeutic approach.

AIMS

Here, we provide an overview of the IDH2- mutated sinonasal tumors, discuss histopathologic and clinical features, and focus on molecular diagnostics and novel immunohistochemical markers.

RESULTS

A review of the literature reveals 82 reported cases with IDH2 -mutated sinonasal tumors (IST), confirmed either by molecular studies or diagnostic immunohistochemical markers. The mean patient age is 60 years (female/male: 1/1.4), the median tumor size is 5 cm (range: 2.5 to 7.0 cm), and the most common location is the nasal cavity (81%). IST displays tumor necrosis and increased mitotes. Histopathologically, IST shows SNUC-like, large cell neuroendocrine carcinomas-like, or poorly differentiated carcinoma-like features (77%, 12%, and 9%, respectively). The molecular hotspot alterations in mitochondrial IDH2 are: R172S (61%), R172T (19%), R172G (7%), and R172M (3%). Sixty-five percent of tumors are surgically resectable, and all patients received chemotherapy, radiation therapy, or both. Rates of locoregional recurrence and distant metastasis are 60% and 40%, respectively. One-, 3- and 5-year survival rates are 83%, 50%, and 43%, respectively. In all but 1 study, IST is associated with better outcomes than IDH2 wild-type tumors and SMARCB1 -deficient sinonasal tumors.

Top 10 Basaloid Neoplasms of the Sinonasal Tract

BACKGROUND

Basaloid neoplasms of the sinonasal tract represent a significant group of tumors with histological overlap but often with different etiologies (i.e., viral, genetics), clinical management, and prognostic significance.

METHODS

Review.

RESULTS

"Basaloid" generally refers to cells with coarse chromatin in round nuclei and sparse cytoplasm, resembling cells of epithelial basal layers or imparting an "immature" appearance. Tumors with this characteristic in the sinonasal tract are represented by a spectrum of benign to high-grade malignant neoplasms, such as adenoid cystic carcinoma, NUT carcinoma, sinonasal undifferentiated carcinoma, SWI/SNF complex-deficient carcinomas, and adamantinoma-like Ewing sarcoma.

CONCLUSION

In some instances, histology alone may be sufficient for diagnosis. However, limited biopsy material or fine-needle aspiration specimens may be particularly challenging. Therefore, often other diagnostic procedures, including a combination of histology, immunohistochemistry (IHC), DNA and RNA testing, and molecular genetics are necessary to establish an accurate diagnosis.

SWI/SNF-deficient Sinonasal Carcinomas

The classification of poorly differentiated sinonasal carcinomas and their nonepithelial mimics has experienced tremendous developments during the last 2 decades. These recent developments paved the way for an increasingly adopted approach to a molecular-based or etiology-based refined classification of the many carcinoma variants that have been historically lumped into the sinonasal undifferentiated carcinoma category. Among these new achievements, recognition of carcinoma subtypes driven by defects in the Switch/Sucrose nonfermentable (SWI/SNF) chromatin remodeling complex represents a major highlight. This resulted in a new definition of 4 sinonasal entities driven solely or predominantly by Switch/Sucrose nonfermentable complex deficiency: (1) SMARCB1(INI1)-deficient sinonasal carcinoma (lacking gland formation and frequently displaying a non-descript basaloid, and less frequently eosinophilic/oncocytoid morphology, but no features of other definable subtypes), (2) SMARCB1-deficient sinonasal adenocarcinoma (with unequivocal glands or yolk sac-like pattern), (3) SMARCA4-deficient undifferentiated (sinonasal undifferentiated carcinoma-like) carcinoma (lacking glandular or squamous immunophenotypes), and (4) SMARCA4-deficient subset (~80%) of sinonasal teratocarcinosarcoma. Fortunately, diagnostic loss of all these proteins can be detected by routine immunohistochemistry, so that genetic testing is not mandatory in routine practice. This review summarizes the main demographic, clinicopathological, and molecular features of these new entities.

DEK::AFF2 Fusion Carcinomas of Head and Neck

A novel DEK::AFF2 fusion carcinoma was recently described in 29 patients who originally presented with non-viral-associated nonkeratinizing squamous cell carcinoma. The tumors occurred at multiple sites in the head and neck including in the sinonasal tract, middle ear, and temporal bone. This tumor behaves aggressively involving adjacent vital structures, frequently recurs, and is inclined to develop lymph node and distant metastasis. This review aims to summarize the demographic, clinical, pathologic, immunophenotypic features, and pattern of molecular alterations as well as to discuss the differential diagnosis of DEK::AFF2 fusion carcinoma.

Updates in management strategies of locally advanced sinonasal malignancy

PURPOSE OF REVIEW

Sinonasal tumors are a rare heterogenous group of pathologies with poor prognosis. In recent years better definition and understanding of histology, molecular classification, biological behavior and advances in therapy have resulted in improved prognosis. The purpose of this review is to give an updated summary of the recent advances in treatment, and where relevant, with references to pathology classifications.

RECENT FINDINGS

Recent publications highlight the role of induction chemotherapy and advances in radiotherapy in advanced cancers. In addition, better understanding of genomics and histology specific treatment algorithms has led to more tailored treatment approaches. The role of immunotherapy and targeted therapy are yet to be explored.

SUMMARY

This review gives an up to date summary of the advances in contemporary management strategies for locally advanced sinonasal malignancies and can serve as a guide for researchers and clinicians.

Human papillomavirus-related multiphenotypic sinonasal carcinoma

Human papillomavirus-related multiphenotypic sinonasal carcinoma (HMSC) is a rare primary tumor of the sinonasal tract that has been reported recently. It is reportedly associated with human papillomavirus infection. The tumor presents with glandular cyst-like histology, but some cases exhibit squamous epithelialization and are positive on p16 immunohistochemical staining. The clinical picture and treatment of this disease have not been established. However, this report describes a recurrent case of this disease treated with salvage surgery. The patient was a 61-year-old woman who presented to the previous doctor with a chief complaint of nasal obstruction. A localized tumor was found in the left nasal cavity and was resected under endoscopic guidance. The postoperative pathological diagnosis was HMSC. Twenty-one months after the surgery, local recurrence was observed, and the patient was referred to our hospital. Since the recurrent lesion had widely infiltrated outside the nasal cavity, extensive resection and reconstructive surgery were performed. Postoperative radiotherapy was performed as an additional treatment. Notably, 13 months have passed since the salvage surgery, and no recurrence has been observed to date.

The Use of Flexible Rhinolaryngoscopy for Allergy-Immunology Practice

Flexible rhinolaryngoscopy is an underused procedure that can provide allergists-immunologists and other physicians with several benefits over existing imaging techniques. In this article, we highlight the many benefits of flexible rhinolaryngoscopy and expand on its safety, cost-effectiveness, and convenience. This article also covers current procedure techniques and assesses the most common indications and relevant clinical findings for which flexible rhinolaryngoscopy can be used to evaluate the nasopharyngeal tract. Videos for the clinician showing some of the most common findings are included.

Cobas HPV Genotyping of FNA Sample Supernatant and Frozen Section Scrapings of Suspected Head and Neck Cancer

The human papillomavirus (HPV) status of squamous cell carcinomas (SCCs) of the head and neck is relevant for therapy planning, staging, and follow-up. Immunohistochemistry (IHC) for p16 is a surrogate marker of HPV status in oropharyngeal SCC, but not at other head and neck sites. We tested if the cobas HPV test was feasible and superior to p16-IHC on fine-needle aspiration (FNA) supernatants and frozen section (FS) scrapings of suspected SCC. A 500 μL aliquots of postcentrifugation supernatant CytoRich Red media of FNA cellblock specimens and scrapings of FS suspended in SurePath media vials were tested with the cobas HPV test and compared with p16-IHC and/or HPV in situ hybridization (ISH) performed on cellblock and/or resections. Twenty-nine (n=29) FNAs were tested for a cobas HPV test, p16, and/or HPV-ISH. The mean collection to testing time was 6.3 days (range: 0 to 24 d). Cobas yielded valid results in all cases; p16-IHC could not be interpreted in 4 (13%) cellblocks; correlation was performed on subsequent resections. Cohen κ correlation for cobas versus p16-IHC/HPV-ISH on FNA samples was 0.9, perfect agreement, sensitivity 100%, specificity 92.3%, positive predictive value 94.1%, negative predictive value 100%. Thirty-four (n=34) scrapings from FS were tested for cobas, p16, and/or HPV-ISH. The mean collection to testing time was 10.4 days (range: 1 to 28 d). Cohen κ correlation for cobas versus p16-IHC/HPV-ISH on FS scrapings was 1, perfect agreement. Sensitivity, specificity, positive predictive value, and negative predictive value was 100%. Cobas genotype was HPV-16 in 87%, HPV-18 in 3%, and HPV-other in 10%. Cobas HPV test in FNA supernatant and FS scrapings outperformed or was equivalent to p16-IHC and provided genotyping information.

Human Papillomavirus-Related Carcinomas of the Sinonasal Tract

Purpose of review

The sinonasal tract is home to a uniquely heterogenous collection of malignant tumors. Human papillomavirus (HPV) has been detected in a number of these, but the virus' role as an oncogenic driver or coincidental finding remains unclear. We aim to highlight five sinonasal tumor types and synthesize the prevalence, etiologic role, and known clinicopathologic relevance of HPV in each.

Recent findings

The last decade has seen an expansion of investigation into HPV's oncogenic and prognostic significance within sinonasal malignancies. The sinonasal tract poses challenges to HPV detection where p16 lacks value as an accurate surrogate. A growing body of data supports a potentially favorable clinical profile for certain sinonasal HPV-positive lesions.

Summary

HPV represents a potential biologically and clinically relevant factor for some sinonasal malignancies. Definitive conclusions regarding HPV's role as a potential oncogenic agent require routine testing using validated methodologies, genomic interrogation, and large-scale prospective studies.

Imaging of human papilloma virus associated oropharyngeal squamous cell carcinoma and its impact on diagnosis, prognostication, and response assessment

The clinical behaviour and outcomes of patients with oropharyngeal cancer (OPC) may be dichotomised according to their association with human papilloma virus (HPV) infection. Patients with HPV-associated disease (HPV+OPC) have a distinct demographic profile, clinical phenotype and demonstrate considerably better responses to chemoradiotherapy. This has led to a reappraisal of staging and treatment strategies for HPV+OPC, which are underpinned by radiological data. Structural modalities, such as CT and MRI can provide accurate staging information. These can be combined with ultrasound-guided tissue sampling and functional techniques (such as diffusion-weighted MRI and 18F-fludeoxyglucose positron emission tomography-CT) to monitor response to treatment, derive prognostic information, and to identify individuals who might benefit from intensification or deintensification strategies. Furthermore, advanced MRI techniques, such as intravoxel incoherent motion and perfusion MRI as well as application of artificial intelligence and radiomic techniques, have shown promise in treatment response monitoring and prognostication. The following review will consider the contemporary role and knowledge on imaging in HPV+OPC.

Human papillomavirus-related carcinoma with adenoid cystic-like features of the sinonasal tract: Case report and literature review

INTRODUCTION AND IMPORTANCE

HPV-related carcinoma with adenoid cystic carcinoma-like features currently known as HPV-related multiphenotypic sinonasal carcinoma (HMSC) is a rare distinct head and neck high-risk HPV-related carcinoma. The high-risk HPV subtypes implicated are particularly type 33,35 and 56. So far this is the first reported rare case of a variant of sinonasal carcinoma in Tanzania.

CASE PRESENTATION

We present a 59-year old female who presented with a history of right-sided nasal obstruction and intermittent epistaxis for about one year and later on had ipsilateral proptosis. A provisional diagnosis of advanced right-sided malignant sinonasal tumor was made. Trans nasal biopsy revealed HMSC.

CLINICAL DISCUSSION

The patient had a right sided fixed neck mass that measured about 7.5 × 8.2 cm. Magnetic resonance imaging (MRI) of the paranasal sinuses revealed a T1 weighted contrasted images that showed a huge extensive enhancing mass (estimated to measure 4.5 × 4.4) involving the nasal cavity, bilateral ethmoid sinuses, frontal and sphenoid sinuses and also the tumor exhibit intracranial extension (anterior cranial fossa) and tend to compress medial walls of both orbits though more marked on the right side. Histopathology and immunohistochemistry confirmed HPV-related multiphenotypic sinonasal carcinoma. The disease was staged to be T4bN3aM0 and the patient was referred for palliative chemoradiation.

CONCLUSION

Although HMSC presents at advanced stage in close to half of cases and has a high-grade histological appearance it paradoxically exhibits a relatively indolent manner with frequent local recurrences. Prompt histopathological diagnosis is important to prevent metastases and HMSC-related deaths.

Radiological features of human papillomavirus-related multiphenotypic sinonasal carcinoma: systematic review and case series

PURPOSE

To comprehensively summarize the radiological characteristics of human papillomavirus (HPV)-related multiphenotypic sinonasal carcinomas (HMSCs).

METHODS

We reviewed the findings for patients with HMSCs who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included nine cases from nine publications that were identified through a systematic review and three cases from our institution. Two board-certified radiologists reviewed and evaluated the radiological images.

RESULTS

The locations in almost all cases included the nasal cavity (11/12, 91.7%). The involved paranasal sinuses included the ethmoid sinus (6/12, 50.0%) and maxillary sinus (3/12, 25.0%). The mean long diameter of the tumors was 46.3 mm. The margins in 91.7% (11/12) of the cases were well-defined and smooth. Heterogeneous enhancement on contrast-enhanced CT, heterogeneous high signal intensities on T2-weighted images and heterogeneous enhancement on gadolinium-enhanced T1-weighted images were noted in 2/2, 5/5, and 8/8 cases, respectively. Mean apparent diffusion coefficient values in two cases of our institution were 1.17 and 1.09 × 10^-3 mm²/s. Compressive changes in the surrounding structures were common (75%, 9/12). Few cases showed intraorbital or intracranial extension. None of the cases showed a perineural spread, neck lymph node metastasis, or remote lesions.

CONCLUSIONS

We summarized the CT and MRI findings of HMSCs. Knowledge of such characteristics is expected to facilitate prompt diagnosis and appropriate management.

HPV51-associated Leiomyosarcoma: A Novel Class of TP53/RB1-Wildtype Tumor With Predilection for the Female Lower Reproductive Tract

Inactivating mutations in tumor suppressor genes TP53 and RB1 are considered central drivers in leiomyosarcomas (LMSs). In high-risk human papillomavirus (HPV)-related tumors, a similar functional outcome is achieved through oncoproteins E6 and E7, which inactivate the p53 and RB1 proteins, respectively. Here, we hypothesized that HPV infection could provide an alternative mechanism for tumorigenesis in a subset of TP53/RB1-wildtype LMS. We evaluated tumor samples from 2585 consecutive unique patients carrying a diagnosis of gynecologic or soft tissue LMS. Tumor DNA and available RNA were analyzed by hybrid-capture-based next-generation sequencing/comprehensive genomic profiling of 406 genes and transcripts (FoundationOneHeme). Of the initial 2585 cases, we excluded 16 based on the presence of molecular alterations that are considered defining for sarcomas other than LMS. In the remaining 2569 cases, we searched for LMS that were TP53/RB1-wildtype (n=486 of 2569; 18.9%). We also searched LMS tumors for HPV sequences that we then classified into genotypes by de novo assembly of nonhuman sequencing reads followed by alignment to the RefSeq database. Among TP53/RB1-wildtype LMS, we identified 18 unique cases harboring HPV sequences. Surprisingly, most (n=11) were HPV51-positive, and these 11 represented all HPV51-positive tumors in our entire LMS database (n=11 of 2569; 0.4%). The absence of genomic alterations in TP53 or RB1 in HPV51-positive LMS represented a marked difference from HPV51-negative LMS (n=2558; 0% vs. 72% [P<0.00001], 0% vs. 53% [P=0.0002]). In addition, compared with HPV51-negative LMS, HPV51-positive LMS were significantly enriched for genomic alterations in ATRX (55% vs. 24%, P=0.027) and TSC1 (18% vs. 0.6%, P=0.0047). All HPV51-positive LMS were in women; median age was 54 years at surgery (range: 23 to 74 y). All known primary sites were from the gynecologic tract or adjacent anogenital area, including 5 cases of vaginal primary site. Histology was heterogeneous, with evaluable cases showing predominant epithelioid (n=5) and spindle (n=5) morphology. In situ hybridization confirmed the presence of high-risk HPV E6/E7 mRNA in tumor cells in three of three evaluable cases harboring HPV51 genomic sequences. Overall, in our pan-LMS analysis, HPV reads were identified in a subset of TP53/RB1-wildtype LMS. For all HPV51-associated LMS, the striking absence of any detectable TP53 or RB1 mutations and predilection for the female lower reproductive tract supports our hypothesis that high-risk HPV can be an alternative tumorigenic mechanism in this distinct class of LMS.

Metatypical Adenoid Cystic Carcinoma: A Variant Showing Prominent Squamous Differentiation With a Predilection for the Sinonasal Tract and Skull Base

Adenoid cystic carcinoma is a malignant salivary gland neoplasm, commonly involving the major and minor salivary glands. Adenoid cystic carcinoma arising in the skull base region is considerably less common and is characterized by aggressive clinical behavior, perineural invasion, and intracranial extension. Classically, these tumors are composed of ductal and myoepithelial cells, arranged as tubules and cribriform structures, as well as in a solid pattern when higher in grade. The distinctive molecular findings in this tumor are the gene fusions involving the MYB/MYBL1 and NFIB genes. Squamous differentiation, trabecular, and macrocystic growth patterns are exceedingly rare in these tumors and when present can cause significant diagnostic challenges. Squamous differentiation, in particular, is considered by many to be an exclusion criterion for adenoid cystic carcinoma outside of cases with high-grade transformation. In addition, a similar-appearing tumor with squamous differentiation, namely human papillomavirus-related multiphenotypic sinonasal carcinoma, has recently been defined, further complicating this differential diagnosis. Recently, we have come across 3 cases of adenoid cystic carcinomas involving the sinonasal tract and skull base having extensive interconnecting trabecular growth, macrocysts, and squamous differentiation, yet demonstrating the signature fusions involving MYB-NFIB and MYBL1-NFIB by RNA sequencing. In this article, we describe the clinical, histomorphologic, and imaging findings of these cases and propose the appellation "metatypical adenoid cystic carcinoma" for this uncommon variant morphology.

Molecular Detection Methods in HPV-Related Cancers

Human papillomavirus (HPV) is responsible for most cervical cancers and some head and neck cancers, including oropharyngeal squamous cell carcinoma and sinonasal carcinoma. Cervical cancer is commonly diagnosed by liquid-based cytology, followed by HPV testing using commercially available DNA polymerase chain reaction (PCR), p16 immunohistochemistry (IHC), or DNA/RNA in situ hybridization. HPV in head and neck cancers is commonly diagnosed by p16 IHC or by RT-qPCR of HPV-16 E6 and E7 oncoproteins. Droplet digital PCR has been reported as an ultrasensitive and highly precise method of nucleic acid quantification for biomarker analysis and has been used to detect oncogenic HPV in oropharyngeal and cervical cancers.

Analysis of Human Papillomavirus (HPV) and Polyomaviruses (HPyVs) in Adenoid Cystic Carcinoma (AdCC) of the Head and Neck Region Reveals Three HPV-Positive Cases with Adenoid Cystic-like Features

An aetiological role of human papillomavirus (HPV) and/or human polyomaviruses (HPyVs) has been proposed in adenoid cystic carcinoma (AdCC). Moreover, HPV-related multiphenotypic carcinoma (HMSC) was recently introduced as an emerging entity of the sinonasal region. Here, we primarily want to study the role of HPV/HPyV in a large AdCC cohort and, secondly, possibly identify and characterize HMSC. Tumour DNA from 68 patients initially diagnosed with AdCC between 2000 and 2012 was, therefore, tested for 27 HPV types and 10 HPyVs. HPV DNA-positive samples were micromorphologically re-evaluated, further stained for p16^INK4a, S100, p63 and CD117 and tested for the presence of the MYB-NFIB fusion transcript. Notably, no samples were HPyV-positive, while one sinonasal and two tonsillar carcinomas were HPV- and p16-positive. After re-evaluating the micromorphology, immunohistochemistry and presence of fusion transcripts, all tumours had the same appearance and fitted within the diagnosis of HMSC, but in all these three cases, the morphology of the HMSC and basaloid squamous cell carcinoma was overlapping. We conclude that HPV and HPyV have no major role in AdCC. However, based on our data, we also suggest that HMSC should be considered as a basaloid variant of squamous cell carcinoma, and not its own entity, until better characterized.

IDH1/2 Mutations in Sinonasal Undifferentiated Carcinomas: Previously Undescribed IDH2 R172K and R140x Variants

Sinonasal undifferentiated carcinoma (SNUC) is a rare, poorly defined sinonasal epithelial neoplasm from which several genetically defined entities are emerging.IDH1/2mutations were recently identified in a subset of SNUC. However, the ideal method for the detection of these mutations remains to be established. Cases diagnosed as SNUC between 2010 and 2020 were retrieved. Immunohistochemistry was performed using IDH1/2 mutant-specific antibody MsMab-1. Quantitative real-time polymerase chain reaction (qPCR) was performed on genomic DNA extracted from formalin-fixed paraffin-embedded tissue using 2 kits to detectIDH1/2mutations. Sanger sequencing was performed in a subset of cases. Thirty-eight cases of SNUC were identified, 18 of which showedIDH1/2mutations by qPCR (47.4%).IDH2R172K and R140x were most frequent, each seen in 6 cases (33.3%). Sanger sequencing identifiedIDH1/2mutations in 4 out of 21 cases (19%) and did not detect mutations identified by qPCR in 7 cases. On immunohistochemistry, strong IDH positivity was present in 2 cases (5.3%), 1 of which hadIDH2mutation, while no mutation was detected in the other. Our results demonstratingIDH2R172K andIDH2R140x variants are a novel finding in SNUC. Immunohistochemistry and Sanger sequencing have low sensitivity for detection ofIDH1/2mutations, and qPCR-based assays may be utilized, particularly in resource-limited settings where access to sophisticated sequencing techniques are difficult.