Juvenile onset recurrent respiratory papillomatosis: What do we know in 2024 ?

Juvenile onset recurrent respiratory papillomatosis is a lifelong benign squamous lesion associated with HPV infection, particularly HPV6 and HPV11 genotypes. These lesions are rare, but can lead to laryngeal obturations, which can cause disabling dyspnea, or transform into squamous cell carcinoma. The aim here is to provide an epidemiological, biological and clinical overview of this pathology, particularly in children, in order to understand the issues at stake in terms of research and the development of medical and therapeutic management tools.

Characterization of a Molecularly Distinct Subset of Oncocytic Pleomorphic Adenomas/Myoepitheliomas Harboring Recurrent ZBTB47-AS1::PLAG1 Gene Fusion.

Recurrent gene fusions are common in salivary gland tumors including benign tumors, such as pleomorphic adenoma (PA) and myoepithelioma (ME). In cases where chromosomal rearrangement is identified in the pleomorphic adenoma gene 1 (PLAG1) gene, different gene partners are found. Oncocytic metaplasia, characterized by oncocytes with abundant eosinophilic granular cytoplasm and hyperchromatic nuclei, is a well-known phenomenon in salivary gland neoplasms. However, the pure oncocytic variant of PA/ME showed PLAG1 gene rearrangements involving various gene partners at the molecular level, without any recurrent fusion being found. Our study includes 20 cases of PA/ME, with 11 females and 9 males. The age of patients ranged from 37 to 96 years, with a median age of 62.8 years. Most tumors originate from the parotid gland. The median size of the tumor was 26.5 mm (range: 13 to 60 mm). Among the 20 cases, 14 were a pure oncocytic variant of PA/ME, whereas 6 cases showed focal oncocytic or oncocytic-like aspects. Molecular studies on 20 cases of PA/ME were conducted. A novel recurrent ZBTB47-AS1::PLAG1 fusion was identified in 6 of 12 cases with pure oncocytic metaplasia, whereas the other cases had PLAG1 gene fusion with different gene partners. The transcriptomic analysis of the cases harboring ZBTB47-AS1::PLAG1 fusion demonstrated that these tumors have a distinct molecular profile from conventional PA/ME. This study reveals a unique subset in the oncocytic PA/ME spectrum characterized by pure oncocytic morphology with larger oncocytic cells and recurrent ZBTB47-AS1::PLAG1 fusion. It also highlights the transcriptomic distinctness of salivary gland adenomas with pure oncocytic metaplasia in the spectrum of salivary gland neoplasms. Further studies are needed to better understand the oncocytic variant of PA/ME and to determine the true nature of oncocytic cells in PA/ME.

[Salivary gland tumors: 2022 WHO blue book and beyond]. / Tumeurs des glandes salivaires : OMS 2022 et au-delà.

In 2022, the 5th edition of the WHO classification of Head and Neck tumors was published online. In the salivary gland chapter, a new benign entity, the keratocystoma, was introduced. The sclerosing polycystic adenosis has been recognized as tumoral and is now termed sclerosing polycystic adenoma. The striated duct adenoma now has its own dedicated chapter. Additionally, a new variant of pleomorphic adenoma, termed "canalicular adenoma-like," has been incorporated. Regarding malignant tumors of the salivary glands, significant doubts now exist regarding the actual existence of oncocytic carcinoma, which has been reclassified among emerging entities. Two new malignant entities have also emerged: microsecretory adenocarcinoma and microcystic sclerosing adenocarcinoma. Finally, primary mucinous adenocarcinoma of the salivary glands has been acknowledged as a distinct entity.

Desmoplastic fibroma of the jaw: A case report and review of the literature.

Desmoplastic fibroma (DF) is a rare benign bone tumor adopting an aggressive behavior, representing a challenge for clinical and radiographic diagnosis. This case report focused on a 31-year-old man with a large mandibular lesion with severe displacements of the mandibular teeth. Only a combination of paraclinical findings allows a definitive diagnosis to be made. Cervicofacial MRI revealed a low T1 signal intensity with peripheral enhancement after Gadolinium, and T2 hyperintense signal, while PET scan showed a moderate metabolism. Bone biopsy with immunohistochemical analysis allowed for definitive diagnosis of DF after eliminating the main differential diagnosis (fibrous dysplasia, fibrosarcoma, desmoid tumor, and osteosarcoma). The patient was successfully treated by large mandibular resection and reconstruction with a free-fibular bone flap".

[Fusion genes in salivary gland tumors]. / Les tumeurs des glandes salivaires associées à des transcrits de fusion.

Salivary gland tumors represent a diagnostic challenge for pathologists due to their rarity, their very wide histopathological and immuno-phenotypic spectrum, and the recent identification of new entities. This article presents the main molecular characteristics of these tumors in order to allow any pathologist to perceive the diagnostic tracks of these ENT tumors and to better guide the molecular approach to establish the diagnosis and guide therapy.

[Translocated sinonasal tumors]. / Tumeurs nasosinusiennes à translocation.

In recent years, several nasal cavity and sinus entities have been described with fusion genes. Salivary gland tumors with fusion genes will not be discussed in this article, but it should be kept in mind that accessory salivary glands are present in the nasal cavity and sinuses and can therefore lead to tumoral lesions. Entities with specific or more frequently described rearrangements in the nasal cavities and sinuses are DEK::AFF2 squamous cell carcinomas,;non-intestinal and non-salivary nasosinusal adenocarcinomas, some of which displaying ETV6 gene rearrangements; biphenotypic nasosinusal sarcomas, most of which displaying PAX3 gene rearrangements; and Ewing's adamantinoma-like sarcomas, which display the same rearrangements as conventional Ewing's sarcomas, mainly the EWSR1::FLI1 rearrangement. Each entity will be described morphologically, immunohistochemically, and prognostically.

Micromolding-based encapsulation of mesenchymal stromal cells in alginate for intraarticular injection in osteoarthritis.

Osteoarthritis (OA) is an inflammatory joint disease that affects cartilage, subchondral bone, and joint tissues. Undifferentiated Mesenchymal Stromal Cells are a promising therapeutic option for OA due to their ability to release anti-inflammatory, immuno-modulatory, and pro-regenerative factors. They can be embedded in hydrogels to prevent their tissue engraftment and subsequent differentiation. In this study, human adipose stromal cells are successfully encapsulated in alginate microgels via a micromolding method. Microencapsulated cells retain their in vitro metabolic activity and bioactivity and can sense and respond to inflammatory stimuli, including synovial fluids from OA patients. After intra-articular injection in a rabbit model of post-traumatic OA, a single dose of microencapsulated human cells exhibit properties matching those of non-encapsulated cells. At 6 and 12 weeks post-injection, we evidenced a tendency toward a decreased OA severity, an increased expression of aggrecan, and a reduced expression of aggrecanase-generated catabolic neoepitope. Thus, these findings establish the feasibility, safety, and efficacy of injecting cells encapsulated in microgels, opening the door to a long-term follow-up in canine OA patients.

Histological Severity Risk Factors Identification in Juvenile-Onset Recurrent Respiratory Papillomatosis: How Immunohistochemistry and AI Algorithms Can Help?

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition characterized by the repeated growth of benign exophytic papilloma in the respiratory tract. The course of the disease remains unpredictable: some children experience minor symptoms, while others require multiple interventions due to florid growth. Our study aimed to identify histologic severity risk factors in patients with JoRRP. Forty-eight children from two French pediatric centers were included retrospectively. Criteria for a severe disease were: annual rate of surgical endoscopy ≥ 5, spread to the lung, carcinomatous transformation or death. We conducted a multi-stage study with image analysis. First, with Hematoxylin and eosin (HE) digital slides of papilloma, we searched for morphological patterns associated with a severe JoRRP using a deep-learning algorithm. Then, immunohistochemistry with antibody against p53 and p63 was performed on sections of FFPE samples of laryngeal papilloma obtained between 2008 and 2018. Immunostainings were quantified according to the staining intensity through two automated workflows: one using machine learning, the other using deep learning. Twenty-four patients had severe disease. For the HE analysis, no significative results were obtained with cross-validation. For immunostaining with anti-p63 antibody, we found similar results between the two image analysis methods. Using machine learning, we found 23.98% of stained nuclei for medium intensity for mild JoRRP vs. 36.1% for severe JoRRP (p = 0.041); and for medium and strong intensity together, 24.14% for mild JoRRP vs. 36.9% for severe JoRRP (p = 0.048). Using deep learning, we found 58.32% for mild JoRRP vs. 67.45% for severe JoRRP (p = 0.045) for medium and strong intensity together. Regarding p53, we did not find any significant difference in the number of nuclei stained between the two groups of patients. In conclusion, we highlighted that immunochemistry with the anti-p63 antibody is a potential biomarker to predict the severity of the JoRRP.

Juvenile-Onset Recurrent Respiratory Papillomatosis Aggressiveness: In Situ Study of the Level of Transcription of HPV E6 and E7.

Juvenile-onset recurrent respiratory papillomatosis (JoRRP) is a condition related to HPV 6 and 11 infection which is characterized by the repeated growth of benign exophytic papilloma in the respiratory tract. Disease progression is unpredictable: some children experience minor symptoms, while others require multiple interventions due to florid growth. The aim of this study was to explore the biomarkers of JoRRP severity on a bicentric cohort of forty-eight children. We performed a CISH on the most recent sample of papilloma with a probe targeting the mRNA of the E6 and E7 genes of HPV 6 and 11 and an immunostaining with p16INK4a antibody. For each patient HPV RNA CISH staining was assessed semi-quantitatively to define two scores: 1+, defined as a low staining extent, and 2+, defined as a high staining extent. This series contained 19 patients with a score of 1+ and 29 with a score of 2+. Patients with a score of 2+ had a median of surgical excision (SE) per year that was twice that of patients with a score of 1+ (respectively 6.1 versus 2.8, p = 0.036). We found similar results with the median number of SE the first year. Regarding p16INK4a, all patients were negative. To conclude, HPV RNA CISH might be a biomarker which is predictive of disease aggressiveness in JoRRP, and might help in patient care management.

HPV Detection in Head and Neck Squamous Cell Carcinomas: What Is the Issue?

Besides classic tobacco and alcohol risk factors, human papillomavirus (HPV) plays a role in the development of a subset of head and neck squamous cell carcinomas (HNSCCs), and notably oropharynx squamous cell carcinomas (OPSCCs). HPV-induced OPSCCs have a different biological behavior and a better prognosis compared to non-HPV-induced OPSCCs and the eighth-edition TNM classification now separates these two entities. Therefore, determining the HPV status of patients with OPSCC is now essential for treatment, prognosis, and development of clinical trials. In this review, after reminding essential steps of HPV implication in the cell cycle, we describe the existing tools that are currently feasible in routine practice according to facilities available in health structures, with their benefits and drawbacks: HPV PCR, E6/E7 mRNA RT-PCR, E6/E7 mRNA in situ hybridization, HPV DNA in situ hybridization, and P16 immunochemistry. Besides these traditional HPV detection tools, novel diagnostic approaches are being evaluated for HPV-induced OPSCC "ultrastaging." E6 humoral response and ddPCR-detecting HPVct DNA are two techniques performed on blood and are therefore non-invasive. Baseline E6 humoral levels could have a prognostic value, and HPVct DNA could be helpful for HPV OPSCC recurrence monitoring. At last, next-generation sequencing (NGS)-based "capture HPV" is a technique feasible on biopsies and circulating DNA material. It helps characterize HPV integration status and sites, and it could define prognostic subgroups in HPV-induced OPSCC. These novel precision detection tools could be further integrated in the care of patients with HPV-induced OPSCC.

[Vaccination against papillomavirus : outstanding issues]. / Vaccination contre les papillomavirus : les questions en suspens.

Vaccination against papillomavirus: outstanding issues. Human papillomavirus or HPV are oncogenic viruses involved in many cancers. It is estimated that around 5% of cancers worldwide are linked to HPV infection. Cancers of the cervix, vagina, vulva, anus, penis and throat (tonsil) are virally induced in proportions ranging from 35 to almost 100%. These cancers are not all easily detected and the detection of lesions is not always simple and effective. Prophylactic anti-HPV vaccination is recognized for its effectiveness in the prevention of cervical cancers, its place in the prevention of other induced HPV cancers remains debated.

Vaccination contre les papillomavirus : les questions en suspens. Les papillomavirus humains sont des virus oncogènes impliqués dans de nombreux cancers. On considère qu'environ 5 % des cancers dans le monde sont liés à une infection par un papillomavirus. Les cancers du col de l'utérus, du vagin, de la vulve, de l'anus, du pénis et de la gorge (amygdale) sont viro-induits selon des proportions variant de 35 à presque 100 %. Ces cancers ne sont pas tous facilement détectés, et les dépistages de lésions ne sont pas toujours simples et efficaces. La vaccination prophylactique contre les papillomavirus est reconnue pour son efficacité dans la prévention des cancers du col de l'utérus ; sa place dans la prévention des autres cancers induits par les papillomavirus reste débattue.

The Microenvironment of Head and Neck Cancers: Papillomavirus Involvement and Potential Impact of Immunomodulatory Treatments.

Cancer progression can be understood as the result of deregulation of tumors' immune microenvironments. Recent studies of the alterations of microenvironments highlight their significant influence on the prognosis of patients with head and neck squamous cell carcinoma (HNSCC). It is necessary to better characterize tumor-infiltrating lymphocytes by focusing, in particular, on the tumor escape mechanisms from immune surveillance. One of the best described tumor immune system evasion mechanisms is the expression of co-stimulation molecules that constitute so-called "immune checkpoints". These molecules regulate the immune response by either activating or inhibiting its effects. The programmed cell death 1 (PD-1) surface protein is an inhibitory co-stimulation molecule that induces exhaustion of activated T-lymphocytes (TLs, T cells) through binding with its ligands, PD-L1 and PD-L2. Half of HNSCCs exhibit PD-L1 expression with higher expression identified in human papillomavirus (HPV) positive tumors. Numerous studies have shown differences between the microenvironments of HPV+ and HPV- cancers. Notably, infiltrations of exhausted CD4+ PD1+ and CD8+ PD1+ T cells are far higher in the microenvironment of HPV+ tumors. The FDA has approved the use of molecules that target PD-1 for the treatment of HNSCC. The first results of clinical trials with anti-PD-1 blockers in HNSCC show improved patient survival, particularly long-term survival without recurrence. However, discordant results were sometimes observed, and improvements in defining cellular predictive markers are necessary. With the development of immunotherapies, pathologists play a role in the selection of patients who are eligible for specific treatments and assessment of their prognosis in greater detail. An automated, quantitative in situ imaging system that integrates both multispectral imaging and automated slide scanning could be developed in pathology laboratories. The evaluation of PD-L1 expression has only been used to stratify the administration of first-line immunotherapy. The validation of these tests and their routine interpretation is essential. No specific recommendation is adopted for HPV+ HNSCC.

[Study of the Human Papillomavirus (HPV) prevalence in head and neck carcinomas in a French monocentric cohort of 372 patients]. / Étude de la prévalence du papillomavirus (HPV) dans les cancers des voies aéro-digestives sur une cohorte unicentrique française de 372 patients.

INTRODUCTION: French data about HPV role in head and neck carcinomas are sparse, although French patients are mostly heavy smokers. In this series of oropharyngeal et non-oropharyngeal tumors, we aimed to determine what were the clinicopathological features associated with HPV and evaluate survival of patients according to HPV status. METHODS: Three hundred and seventy-two cases of head and neck squamous cell carcinomas were reviewed and clinicopathological data were detailed. For each case, we performed a HPV PCR and an immunostaining against p16 protein (paraffin embedded tissues). RESULTS: The series contained 90% of heavy smokers and 36% of tumors were located in oropharynx. HPV DNA was detected in 46% of oropharyngeal carcinomas and 16% of non-oropharyngeal carcinomas. Genotype 16 was the most frequently detected (84%). Clinicopathological features significantly associated with HPV DNA were: oropharyngeal location; absence of tobacco smoking; nodal involvement; poorly-differentiated non-keratinizing histology; positive p16 immunostaining. HPV infection was significantly associated with a longer survival for oropharyngeal carcinomas. It was not the case for non-oropharyngeal carcinomas. CONCLUSION: In this French series with lot of heavy smokers, under half of carcinomas are HPV induced. Clinicopathological features and survival data associated with HPV infection are the same as those classically described in literature.

Chromogenic In Situ Hybridization as a Tool for HPV-Related Head and Neck Cancer Diagnosis.

Human papillomavirus (HPV) infection is a major risk factor for a subtype of oropharyngeal squamous cell carcinoma (OPSCC), which tends to be associated with a better outcome than alcohol- and tobacco-related OPSCC. Chromogenic in situ hybridization (CISH) of HPV viral RNA could allow the semiquantitative evaluation of viral transcripts of the oncogenic proteins E6 and E7 and an in situ visualization with a good spatial resolution. This technique allows the diagnosis of an active infection with the visualization of HPV transcription in the tumoral HPV-infected cells. An advantage of this technique is the avoidance of contamination from nonneoplastic HPV-infected cells adjacent to the tumor. Overall, its good diagnosis performances have it considered to be the gold standard for active HPV infection identification. Since E6 and E7 viral protein interaction with cell proteins pRb and p53 is mandatory for cell transformation, HPV RNA CISH is functionally relevant and acutely reflects active oncogenic HPV infection. This technique is clinically relevant as well since "low" or "high" HPV transcription levels helped the identification of two prognosis groups among HPV-related p16-positive head and neck cancer patients. Here we present the protocol for manual HPV RNA CISH performed on formalin-fixed paraffin-embedded (FFPE) slides with a kit obtained from the manufacturer. Instead of chromogenic revelation, RNA in situ hybridization may also be performed with fluorescent revelation (RNA FISH). It may also be combined with conventional immunostaining.

Telomerase Activation and ATRX Mutations Are Independent Risk Factors for Metastatic Pheochromocytoma and Paraganglioma.

PURPOSE: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors. Whereas most PPGLs are benign, up to 20% may become metastatic with SDHB- and FH-mutated tumors showing the higher risk. We aimed at determining the contribution of immortalization mechanisms to metastatic progression.Experimental Design: Immortalization mechanisms were investigated in 200 tumors. To identify telomerase (+) tumors, we analyzed genomic alterations leading to transcriptional activation of TERT comprising promoter mutations, hypermethylation and gain copy number. To identify tumors that activated the alternative lengthening of telomere (ALT) mechanism, we combined analyses of telomere length by slot blot, telomere heterogeneity by telomere FISH, and ATRX mutations by next-generation sequencing. Univariate/multivariate and metastasis-free survival (MFS) and overall survival (OS) analyses were carried out for assessment of risk factors and clinical outcomes. RESULTS: Only 37 of 200 (18.5%) tumors achieved immortalization. Telomerase activation occurred in 12 metastatic tumors and was prevalent in SDHB-mutated paragangliomas (P = 2.42e-09). ALT features were present in 25 tumors, mostly pheochromocytomas, regardless of metastatic status or molecular group (P = 0.169), yet ATRX mutations were found preferentially in SDHB/FH-mutated metastatic tumors (P = 0.0014). Telomerase activation and ATRX mutations were independent factors of poor prognosis: MFS (hazard ratio, 48.2 and 33.1; P = 6.50E-07 and 1.90E-07, respectively); OS (hazard ratio, 97.4 and 44.1; P = 4.30E-03 and 2.00E-03, respectively) and were associated with worse MFS and OS (log-rank tests P < 0.0001). CONCLUSIONS: Assessment of telomerase activation and ATRX mutations could be used to identify metastatic PPGLs, particularly in tumors at high risk of progression.

HPV RNA CISH score identifies two prognostic groups in a p16 positive oropharyngeal squamous cell carcinoma population.

HPV-related and HPV-unrelated oropharyngeal squamous cell carcinomas are two distinct entities according to the Union for International Cancer Control, with a better prognosis conferred to HPV-related oropharyngeal squamous cell carcinomas. However, variable clinical outcomes are observed among patients with p16 positive oropharyngeal squamous cell carcinoma, which is a surrogate marker of HPV infection. We aimed to investigate the prognostic value of RNA CISH against E6 and E7 transcripts (HPV RNA CISH) to predict such variability. We retrospectively included 50 histologically confirmed p16 positive oropharyngeal squamous cell carcinomas (p16 positive immunostaining was defined by a strong staining in 70% or more of tumor cells). HPV RNA CISH staining was assessed semi-quantitatively to define two scores: RNA CISH "low" and RNA CISH "high". Negative HPV RNA CISH cases were scored as RNA CISH "low". This series contained 29 RNA CISH low cases (58%) and 21 RNA CISH high cases (42%). Clinical and pathologic baseline characteristics were similar between the two groups. RNA CISH high staining was associated with a better overall survival in both univariate and multivariate analyses (p = 0.033 and p = 0.042, respectively). Other recorded parameters had no prognostic value. In conclusion, HPV RNA CISH might be an independent prognostic marker in p16 positive oropharyngeal squamous cell carcinomas and might help guide therapeutics.