Quantitative assessment of p16 expression in FNA specimens from head and neck squamous cell carcinoma and correlation with HPV status

CytoLyt fixation impedes insulinoma-associated protein 1 (INSM1) immunoreactivity compared to formalin fixation

INTRODUCTION

Insulinoma-associated protein 1 (INSM1) is an immunohistochemical marker commonly used to confirm cytomorphological concordant neuroendocrine tumors/carcinomas (NETs/NECs), demonstrating high utility in small samples. Previous reports have suggested comparable INSM1 staining in CytoLyt-fixed cell blocks and formalin-fixed surgical pathology specimens. This study aimed to assess INSM1 immunoreactivity using both fixation methods and investigate potential factors contributing to its variable expression.

MATERIALS AND METHODS

A retrospective query was performed (03/31/21-05/31/22) for NET/NEC cases that had both formalin- and CytoLyt-fixed cell blocks. We collected clinical data and reporting of immunostains for each case. INSM1 staining was evaluated in both fixation methods, and reported as positive, negative, or equivocal. Equivocal INSM1 staining was further scored as a percentage of 1%-100% and intensity of weak (faint staining), moderate (darker staining), and strong (dense staining).

RESULTS

Our search identified 20 cases from diverse body sites, including mediastinal lymph nodes (40%), pancreas (35%), lung (20%), and porta hepatis lymph nodes (5%). All cases exhibited a widespread positivity (over 90%) in formalin-fixed cell blocks. In contrast, CytoLyt fixed cells showed a negative stain in 65% of cases and 30% exhibited an equivocal positivity.

CONCLUSIONS

While INSM1 is previously reported as a sensitive (75%-100%) and specific (82.7%-100%) marker for NET/NECs, our study found a reduced immunohistochemical staining in CytoLyt-fixed cell blocks. Consequently, false negative INSM1 immunohistochemical results in CytoLyt-fixed cell block material may pose a pitfall in the diagnosis of NET/NEC.

A case of fine-needle aspiration of a neck mass with atypical squamous cells and macrophages

Head and neck lesions often undergo fine-needle aspiration to determine the appropriate management and therapeutic decisions. However, there are numerous diagnostic challenges encountered with these specimens, particularly, if atypical squamous cells are identified. Here, we present a case of an enlarging right neck mass in a 38-year-old female and discuss the diagnostic difficulties and potential pitfalls. Additionally, we review the approach to diagnosis, including differential diagnostic considerations as well as available ancillary testing.

Clinical practice guidelines for management of head and neck squamous cell carcinoma of unknown primary: an AGREE II appraisal

IMPORTANCE

Squamous cell carcinoma without a known primary is an uncommon form of head and neck cancer that requires multidisciplinary collaboration for effective management.

OBJECTIVE

To evaluate the quality of clinical practice guidelines (CPG) using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

DESIGN

A systematic literature search was performed to identify CPGs pertaining to the diagnosis and treatment of head and neck squamous cell carcinoma of unknown primary (HNSCCUP). Data were abstracted from guidelines meeting inclusion criteria and appraised by four independent reviewers in the six domains of quality defined by the AGREE II.

SETTING

Online database.

PARTICIPANTS

None.

EXPOSURE

None.

MAIN OUTCOME(S) AND MEASURE(S)

Quality domain scores and intraclass correlation coefficients (ICC) were calculated across domains to qualify inter-rater reliability.

RESULTS

Seven guidelines met inclusion criteria. Two guidelines achieved a score of > 60% in five or more AGREE II quality domains to gain designation as 'high'-quality content. One "average-quality" guideline authored by the ENT UK Head and Neck Society Council achieved a score of > 60% in three quality domains. The remaining four CPGs demonstrated low-quality content, with deficits most pronounced in domains 3 and 5, suggesting a lack of rigorously developed and clinically applicable information.

CONCLUSIONS AND RELEVANCE

As the diagnosis and treatment of head and neck cancer continues to evolve, identification of high-quality guidelines will become increasingly important. The authors recommend consulting HNSCCUP guidelines from the National Institute for Health and Care Excellence (NICE) or the American Society of Clinical Oncology (ASCO).

TRIAL REGISTRATION

None.

Identification of p53-target genes in human papillomavirus-associated head and neck cancer by integrative bioinformatics analysis

Introduction

Head and neck cancer (HNC) is a highly prevalent and heterogeneous malignancy. Although extensive efforts have been made to advance its treatment, the prognosis remained poor with increased mortality. Human papillomaviruses (HPV) have been associated with high risk in HNC. TP53, a tumor suppressor, is the most frequently altered gene in HNC, therefore, investigating its target genes for the identification of novel biomarkers or therapeutic targets in HPV-related HNC progression is highly recommended.

Methods

Transcriptomic profiles from three independent gene expression omnibus (GEO) datasets, including 44 HPV+ and 70 HPV- HNC patients, were subjected to integrative statistical and Bioinformatics analyses. For the top-selected marker, further in-silico validation in TCGA and GTEx databases and experimental validation in 65 (51 HPV- and 14 HPV+) subjects with histologically confirmed head and neck squamous cell carcinoma (HNSCC) have been performed.

Results

A total of 498 differentially expressed genes (DEGs) were identified including 291 up-regulated genes and 207 down-regulated genes in HPV+ compared to HPV- HNSCC patients. Functional annotations and gene set enrichment analysis (GSEA) showed that the up-regulated genes were significantly involved in p53-related pathways. The integrative analysis between the Hub-genes identified in the complex protein-protein network and the top frequent genes resulting from GSEA showed an intriguing correlation with five biomarkers which are EZH2, MDM2, PCNA, STAT5A and TYMS. Importantly, the MDM2 gene showed the highest gene expression difference between HPV+ and HPV- HNSCC (Average log2FC = 1.89). Further in-silico validation in a large HNSCC cohort from TCGA and GTEx databases confirmed the over-expression of MDM2 in HPV+ compared to HPV- HNSCC patients (p = 2.39E-05). IHC scoring showed that MDM2 protein expression was significantly higher in HPV+ compared to HPV- HNSCC patients (p = 0.031).

Discussion

Our findings showed evidence that over-expression of MDM2, proto-oncogene, may affect the occurrence and proliferation of HPV-associated HNSCC by disturbing the p53-target genes and consequently the p53-related pathways.

High-risk human papillomavirus testing in cytology aspiration samples from the head and neck part 1: a review of the literature on available testing options

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is increasing in incidence and is often first diagnosed on a cytology fine needle aspiration (FNA) specimen of metastatic nodal disease of the neck. In the setting of oropharyngeal squamous cell carcinoma, HPV status defines the disease with HPV-associated tumors having better overall prognosis than those that are HPV negative. Furthermore, metastatic squamous cell carcinoma of the neck of unknown origin requires testing for HPV as a positive result suggests an oropharyngeal primary. As a result, HPV testing in aspirate samples is increasingly important for the proper diagnosis and treatment of patients with head and neck squamous cell carcinoma. Although HPV testing in cervicovaginal cytology specimens is common and well-established, testing in head and neck FNA samples remains challenging. p16 immunohistochemistry is an excellent surrogate marker for HPV in tumors of known or suspected oropharyngeal origin, but the criteria used in histologic specimens may not be appropriate in cytology samples. FNA samples are more frequently hypocellular, and cytology cell blocks have variable fixation and processing steps, limiting the utility of p16 immunohistochemistry. Other potential testing options have been reported in the literature including staining of aspirate smears and molecular testing of liquid-based samples. The American Society of Cytopathology Clinical Practice Committee recently surveyed the American Society of Cytopathology membership to determine the current state of HPV testing in aspirate samples, and this review article is designed to provide a summary of the current literature on various testing options in FNA samples.

High-risk human papillomavirus testing in cytology aspiration samples from the head and neck part 2: a survey of the American Society of Cytopathology community

INTRODUCTION

High-risk human papillomavirus (HR-HPV) status is critical in the diagnosis of oropharyngeal squamous cell carcinoma, informing prognosis and choice of therapy. HR-HPV status additionally plays a key role in the evaluation of squamous cell carcinoma of unknown origin metastatic to cervical lymph nodes. Thus, HR-HPV testing of fine needle aspirate (FNA) specimens from the head and neck is invaluable for accurate diagnosis, prognostication, and treatment planning.

MATERIALS AND METHODS

American Society of Cytopathology members were surveyed to understand the current state of HR-HPV testing on FNA samples from the head and neck. The survey focused on 3 main topic areas: practice setting of respondents, methods of collection and processing of aspirate specimens for HR-HPV testing, and validation of HR-HPV testing methodologies on aspirate samples.

RESULTS

The survey reveals that laboratories employ various methods to detect HR-HPV in FNA samples, most commonly p16 immunohistochemical staining of cell block sections. Although some laboratories have independently validated their HR-HPV detection method, such validation is not universal. Finally, not all respondents currently have HR-HPV testing available, but approximately half of those without a testing method desire to make HR-HPV testing of FNA samples available.

CONCLUSIONS

Survey responses highlight that various testing modalities are utilized for HR-HPV detection in aspirate samples. However, internal laboratory validation of HR-HPV testing for FNA specimens is not ubiquitous despite professional society recommendations.

Detection of Human Papillomavirus in Squamous Lesions of the Conjunctiva Using RNA and DNA In-Situ Hybridization

In-situ hybridization provides a convenient and reliable method to detect human papillomavirus (HPV) infection in formalin-fixed paraffin-embedded tissue. Cases of conjunctival papillomas, conjunctival intraepithelial neoplasia (CIN), conjunctival carcinoma in situ (cCIS), and invasive squamous cell carcinoma (SCC), in which low-risk (LR) and/or high-risk (HR) HPV types were evaluated by RNA or DNA in-situ hybridization, were retrospectively identified. LR HPV types were frequently detected in conjunctival papillomas (25/30, 83%), including 17/18 (94%) with RNA probes, compared to 8/12 (75%) with DNA probes. None of the CIN/cCIS or SCC cases were positive for LR HPV by either method. HR HPV was detected by RNA in-situ hybridization in 1/16 (6%) of CIN/cCIS cases and 2/4 (50%) of SCC cases, while DNA in-situ hybridization failed to detect HPV infection in any of the CIN/cCIS lesions. Reactive atypia and dysplasia observed in papillomas was generally associated with the detection of LR HPV types. Collectively, our findings indicate RNA in-situ hybridization may provide a high-sensitivity approach for identifying HPV infection in squamous lesions of the conjunctiva and facilitate the distinction between reactive atypia and true dysplasia. There was no clear association between HPV infection and atopy in papillomas or dysplastic lesions.

Detection accuracy of the Cobas HPV assay for high-risk HPV in head and neck FNA biopsy specimens

BACKGROUND

This study evaluated the detection accuracy of the Cobas human papillomavirus (HPV) assay for high-risk human papillomavirus (hrHPV) and HPV-16 in head and neck fine-needle aspiration (FNA) specimens with squamous cell carcinoma.

METHODS

Head and neck FNA biopsy specimens from 2012 to 2020 were retrospectively collected. Cobas HPV testing was performed on 90 FNA specimens with valid Cervista HPV testing results. Results of Cobas HPV and Cervista HPV assays were compared. A Linear Array or SPF10-LiPA25 HPV genotyping assay resolved cases with discrepant results. The κ value and accuracy of Cobas HPV testing were calculated. The accuracy of the Cobas HPV assay was also determined in 42 FNA needle-rinse specimens.

RESULTS

Cobas HPV was positive in 82% of the FNA specimens (74 of 90). The concordance between Cobas HPV and Cervista HPV test results was 88.9% (80 of 90) with substantial agreement (κ = 0.669; 95% CI, 0.481-0.856). With HPV genotyping confirmation in cases with discrepant results between the 2 HPV assays, Cobas HPV showed 100% sensitivity and specificity for hrHPV. HPV-16 was detected in 88% of HPV-positive cases (65 of 74). HPV genotyping confirmed 1 false-negative HPV-16 result and 1 false-positive HPV-16 result. Overall, the accuracy of Cobas HPV for HPV-16 was 97.8%. The accuracy of Cobas HPV in FNA needle-rinse specimens was 100%.

CONCLUSIONS

The Cobas HPV assay is highly accurate for determining the HPV status in head and neck FNA specimens. FNA needle rinse is valid for Cobas HPV testing in patients with squamous cell carcinoma.

Immunocytochemistry for diagnostic cytopathology-A practical guide

Cytological specimens, which are obtained by minimally invasive methods, are an excellent source of diagnostic material. Sometimes they are the only material available for diagnosis as well as for prognostic/predictive markers. When cytomorphology is not straightforward, ancillary tests may be required for a definitive diagnosis to guide clinical management. Immunocytochemistry (ICC) is the most common and practical ancillary tool used to reach a diagnosis when cytomorphology is equivocal, to differentiate entities with overlapping morphological features, and to determine the cell lineage and the site of origin of a metastatic neoplasm. Numerous immunomarkers are available, and some are expressed in multiple neoplasms. To rule out entities within a differential diagnosis, the use of more than one marker, sometimes panels, is necessary. ICC panels for diagnostic purposes should be customised based on the clinical context and cytomorphology, and the markers should be used judiciously to preserve material for additional tests for targeted therapies in the appropriate setting. This review offers a practical guide for the use of ICC for diagnostic cytopathology, covering the most commonly encountered non-hematolymphoid diagnostic scenarios in various body sites.