Condylomatous Sinonasal Papilloma-A Distinct (Fourth) Subtype That is Commonly Associated With Low-risk Human Papillomavirus.

Inverted papilloma (IP) is a benign neoplasm of the nasal cavity and paranasal sinuses, known for its variable risk of recurrence and potential for developing carcinoma. Emerging evidence has shown high rates of activating EGFR mutation, and a smaller subset is associated with low-risk human papillomavirus (lrHPV). While certain morphologic features, including an inverted growth pattern, are well-established, the presence of condylomatous features, such as large fungating lesions with thick undulating surface epithelium, hyperkeratosis, cytoplasmic clearing, raisinoid nuclei, and binucleation (koilocytic changes) in low-risk HPV-associated IP suggests that these tumors may be a distinct subtype of sinonasal papilloma (SP) with features similar to low-risk HPV-associated anogenital condylomas.

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.

DEK :: AFF2 Fusion Sinonasal and Skull Base Nonkeratinizing Squamous Cell Carcinoma : A Clinical Outcome Study Compared With Conventional Sinonasal Squamous Cell Carcinoma.

DEK :: AFF2 fusion nonkeratinizing squamous cell carcinoma (NKSCC) is an emerging entity in the sinonasal tract, temporal bone, and skull base. However, the clinical behavior of these tumors has not been well studied. Here, we report the largest cohort of DEK :: AFF2 carcinomas to determine if morphology, mitotic rate, and/or Ki-67 IHC are associated with patient outcomes, including a comparison with high-risk human papillomavirus (HPV)-associated and independent patients.

Fungal Infections of the Sinonasal Tract and Their Differential Diagnoses.

Fungal rhinosinusitis is a broad group of diseases that includes noninvasive and invasive forms with overlapping clinical presentations. While most cases of fungal rhinosinusitis follow an indolent clinical course, surgical pathologists play a crucial role in early identification of life-threating subtypes, specifically invasive fungal rhinosinusitis. This review describes fungal infections of the sinonasal tract and their histopathologic mimickers.

Head and neck squamous cell carcinomas of unknown primary: Can ancillary studies help identify more primary tumor sites?

A subset of head and neck squamous cell carcinomas present solely as metastatic disease in the neck and are of unknown primary origin (SCCUP). Most primary tumors will ultimately be identified, usually in the oropharynx. In a minority of cases, the primary site remains elusive.

Preexisting tumor-resident T cells with cytotoxic potential associate with response to neoadjuvant anti-PD-1 in head and neck cancer.

About 50% of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) experience recurrences after definitive therapy. The presurgical administration of anti-programmed cell death protein 1 (PD-1) immunotherapy results in substantial pathologic tumor responses (pTR) within the tumor microenvironment (TME). However, the mechanisms underlying the dynamics of antitumor T cells upon neoadjuvant PD-1 blockade remain unresolved, and approaches to increase pathologic responses are lacking.

Biphenotypic Sinonasal Sarcoma with a Novel PAX7::PPARGC1 Fusion: Expanding the Spectrum of Gene Fusions Beyond the PAX3 Gene.

Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade malignancy occurring in the sinonasal tract that is characterized by dual neural and myogenic differentiation. Rearrangements involving the PAX3 gene, usually with MAML3, are a hallmark of this tumor type and their identification are useful for diagnosis. Rarely, a MAML3 rearrangement without associated PAX3 rearrangement has been described.

Mucoepidermoid carcinoma may be devoid of squamoid cells by immunohistochemistry: expanding the histologic and immunohistochemical spectrum of MAML2- rearranged salivary gland tumours.

Mucoepidermoid carcinoma (MEC) is historically defined by a mix of squamoid, intermediate, and mucous cells, but we have recently encountered several cases lacking immunoreactivity for squamous markers p40, p63, and CK5/6 despite MAML2 fusions. This study will characterise these unique tumours. Ten MEC were collected arising from the parotid gland (n = 4), submandibular gland (n = 2), nasopharynx (n = 1), base of tongue (n = 1), bronchus (n = 1), and trachea (n = 1).

Nuclear expression of AFF2 C-terminus is a sensitive and specific ancillary marker for DEK::AFF2 carcinoma of the sinonasal tract.

DEK::AFF2 carcinoma of the sinonasal tract is an emerging entity. The tumor is typically characterized by papillary proliferation of non-keratinizing squamous epithelial cells with monotonous cytologic features, which may mimic other sinonasal tumors. The confirmation of this gene fusion has thus far relied solely on next-generation sequencing, fluorescence in situ hybridization (FISH), or reverse transcription polymerase chain reaction (RT-PCR).

Comparison of gene fusion detection methods in salivary gland tumors.

Salivary gland neoplasms may pose diagnostic difficulties due to overlapping morphologic features. Recently, specific gene fusions have been discovered that correspond to particular tumor types, and can aid in accurate diagnosis. Gene rearrangements are commonly assessed by fluorescence in situ hybridization (FISH), although use of next-generation sequencing is increasing.

Impact of human papillomavirus on the tumor microenvironment in oropharyngeal squamous cell carcinoma.

Increasing evidence has elucidated the clinicopathological significance of tumor microenvironment (TME) cells. However, TME differences associated with human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC) have not been well characterized. In our study, we comprehensively determined the TME infiltration patterns in 315 OPSCC patients, and systematically correlated the TME phenotypes with genomic characteristics and clinical features of OPSCCs.

Computed Tomography as a Predictor of Sinonasal Inverted Papilloma Origin, Skull Base Involvement, and Stage.

 To investigate the diagnostic performance of computed tomography (CT) to determine the origin, skull base involvement, and stage of sinonasal inverted papilloma (IP).  This is a retrospective cohort study.  This is set at a tertiary care medical center.

DEK-AFF2 fusion-associated papillary squamous cell carcinoma of the sinonasal tract: clinicopathologic characterization of seven cases with deceptively bland morphology.

A novel DEK-AFF2 fusion has been recently identified in four cases of basaloid to nonkeratinizing squamous cell carcinoma (SCC) in the sinonasal tract and middle ear with high-grade morphology. The exceptional response to immune checkpoint inhibitor in the first reported case highlights the potential clinical importance of identifying tumors with DEK-AFF2 fusions. We herein reported the first series of seven cases of DEK-AFF2 fusion-associated sinonasal SCC with deceptively bland morphology, including four cases of low-grade papillary Schneiderian carcinoma, which is a recently described tumor type with unknown molecular underpinnings.

Low Grade Papillary Sinonasal (Schneiderian) Carcinoma: A Series of Five Cases of a Unique Malignant Neoplasm with Comparison to Inverted Papilloma and Conventional Nonkeratinizing Squamous Cell Carcinoma.

There have been a few case reports and one small series of low grade papillary sinonasal (Schneiderian) carcinomas (LGPSC) which mimic papillomas but have overtly invasive growth and which occasionally metastasize. We describe the morphologic, clinical, immunohistochemical, and molecular features of five patients with LGPSC compared with eight cases each of inverted papilloma (IP) and conventional nonkeratinizing squamous cell carcinoma (SCC) with papillary growth. All LGPSC were nested with predominantly pushing invasion, no stromal reaction, and frequent surface papillary growth.

Oropharyngeal Squamous Cell Carcinoma With Discordant p16 and HPV mRNA Results: Incidence and Characterization in a Large, Contemporary United States Cohort.

Early studies estimate that 5% to 10% of oropharyngeal squamous cell carcinomas overexpress p16 but are unassociated with transcriptionally-active high-risk human papillomavirus (HPV). Patients with discordant HPV testing may experience clinical outcomes that differ from traditional expectations. To document the rate of p16 and HPV mRNA positivity, characterize patients with discordant testing, and identify features that may warrant selective use of HPV-specific testing after p16 IHC, a multi-institutional, retrospective review of oropharyngeal squamous cell carcinoma patients with p16 IHC and HPV mRNA testing by reverse transcriptase polymerase chain reaction was performed.

A MicroRNA Expression Signature as Prognostic Marker for Oropharyngeal Squamous Cell Carcinoma.

Background: Improved prognostication of oropharyngeal squamous cell carcinoma (OPSCC) may facilitate individualized patient management. The goal of this study was to develop and validate a prognostic signature based on microRNA sequencing (miRNA-seq) analysis.

Methods: We collected tumor specimens for miRNA-seq analysis from OPSCC patients treated at Washington University in St Louis (n = 324) and Vanderbilt University (n = 130).

A prognostic gene expression signature for oropharyngeal squamous cell carcinoma.

Background: Robust prognostic stratification of patients with oropharyngeal squamous cell carcinoma (OPSCC) is important for developing individualized treatment plans. This study was conducted to develop and validate a clinically feasible prognostic classifier based on transcriptome-wide gene expression profiles.

Methods: Tumor tissues were collected from 208 OPSCC patients treated at Washington University in St.

Neoadjuvant and Adjuvant Pembrolizumab in Resectable Locally Advanced, Human Papillomavirus-Unrelated Head and Neck Cancer: A Multicenter, Phase II Trial.

Purpose: Pembrolizumab improved survival in patients with recurrent or metastatic head and neck squamous-cell carcinoma (HNSCC). The aims of this study were to determine if pembrolizumab would be safe, result in pathologic tumor response (pTR), and lower the relapse rate in patients with resectable human papillomavirus (HPV)-unrelated HNSCC.

Patients And Methods: Neoadjuvant pembrolizumab (200 mg) was administered and followed 2 to 3 weeks later by surgical tumor ablation.

Poorly differentiated thyroid carcinoma of childhood and adolescence: a distinct entity characterized by DICER1 mutations.

Poorly differentiated thyroid carcinomas (PDTC) in young individuals are rare and their clinical and histopathologic features, genetic mechanisms, and outcomes remain largely unknown. Here, we report a detailed characterization of a series of six PDTC in patients ≤21 years old defined by Turin diagnostic criteria studied for mutations and gene fusions characteristic of thyroid cancer using targeted next-generation sequencing (NGS) and whole-exome sequencing (WES). All tumors had solid, insular, or trabecular growth pattern and high mitotic rate, and five out of six tumors showed tumor necrosis.

Transcriptionally Active HPV and Targetable EGFR Mutations in Sinonasal Inverted Papilloma: An Association Between Low-risk HPV, Condylomatous Morphology, and Cancer Risk?

Sinonasal inverted papillomas (IPs) commonly recur, and transform to malignancy in 5% to 10% of patients. It has long been debated whether IPs are caused by high-risk or low-risk (lr) human papillomavirus (HPV) and whether the HPV is transcriptionally active. EGFR mutations have also been recently implicated in the pathogenesis of IP with an unclear relationship to HPV status.

Morphologic, intraoperative, and histologic risk factors for sinonasal inverted papilloma recurrence.

Objective: Sinonasal inverted papillomas (IP) are benign neoplasms with a propensity for local recurrence. Many risk factors are reported, with little consistency between studies. This study aimed to comprehensively assess for demographic, imaging, histopathologic, and intraoperative risk factors for recurrence.

UV Signature Mutations Reclassify Salivary High-grade Neuroendocrine Carcinomas as Occult Metastatic Cutaneous Merkel Cell Carcinomas.

Salivary high-grade neuroendocrine carcinomas (NECs) are rare, occur predominantly in the parotid gland, and are difficult to differentiate from metastatic cutaneous Merkel cell carcinomas (MCCs), which have overlapping morphologic, immunophenotypic, and molecular profiles. Oncogenic Merkel cell polyomavirus (MCPyV), found in 70% to 80% of MCCs, has also been reported in a few salivary NECs, but this is controversial. A promising biomarker to distinguish the 2 tumor types are UV signature mutations.