Standardised definitions and diagnostic criteria for extranodal extension detected on histopathological examination in head and neck cancer: Head and Neck Cancer International Group consensus recommendations.

Detection of extranodal extension on histopathology in surgically treated head and neck squamous cell carcinoma indicates poor prognosis. However, there is no consensus on the diagnostic criteria, interpretation, and reporting of histology detected extranodal extension, which has contributed to conflicting evidence in the literature, and likely clinical inconsistency. The Head and Neck Cancer International Group conducted a three-round modified Delphi process with a group of 19 international pathology experts representing 15 national clinical research groups to generate consensus recommendations for histology detected extranodal extension diagnostic criteria. The expert panel strongly agreed on terminology and diagnostic features for histology detected extranodal extension and soft tissue metastasis. Moreover, the panel reached consensus on reporting of histology detected extranodal extension and on nodal sampling. These consensus recommendations, endorsed by 19 organisations representing 34 countries, are a crucial development towards standardised diagnosis and reporting of histology detected extranodal extension, and more accurate data collection and analysis.

[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.

[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.

Detection of salivary gland and sinonasal fusions by a next-generation sequencing based, ligation-dependent, multiplex RT-PCR assay.

AIMS: The discovery of tumour type-specific gene fusion oncogenes in benign and malignant salivary gland and sinonasal (SGSN) tumours has significantly increased our knowledge about their molecular pathology and classification. METHODS AND RESULTS: We developed a new targeted multiplexed next-generation sequencing (NGS)-based method that utilizes ligation dependent reverse-transcriptase polymerase chain reaction (LD-RT-PCR) to detect oncogenic fusion transcripts involving 116 genes, leading to 96 gene fusions known to be recurrently rearranged in these tumours. In all, 180 SGSN tumours (formalin-fixed, paraffin-embedded samples, 141 specimens and 39 core needle biopsies) from the REFCORpath (French network for rare head and neck cancers) with previously identified fusion genes by fluorescent in situ hybridisation (FISH), RT-PCR, or molecular immunohistochemistry were selected to test its specificity and sensitivity and validate its diagnostic use. Tested tumours encompassed 14 major tumours types, including secretory carcinoma, mucoepidermoid carcinoma, adenoid cystic carcinoma, salivary gland intraductal carcinoma, clear cell carcinoma, pleomorphic adenoma, adamantinoma-like Ewing Sarcoma, EWSR1::COLCA2 sinonasal sarcoma, DEK::AFF2 sinonasal carcinoma, and biphenotypic sinonasal sarcoma. In-frame fusion transcripts were detected in 97.8% of cases (176/180). Gene fusion assay results correlated with conventional techniques (immunohistochemistry [IHC], FISH, and RT-PCR) in 176/180 tumours (97.8%). CONCLUSION: This targeted multiplexed NGS-based LD-RT-PCR method is a robust, highly sensitive method for the detection of recurrent gene fusions from routine clinical SGSN tumours. It can be easily customized to cover new fusions. These results are promising for implementing an integrated NGS system to rapidly detect genetic aberrations, facilitating accurate, genomics-based diagnoses, and accelerate time to precision therapies in SGSN tumours.

[Staging cancers of the oral cavity according to the 8th edition of AJCC TNM system: Issues and recommendations]. / Tumeurs de la cavité orale et classification TNM (8e édition) : problématiques et recommandations.

Stage of cancer at the time of the diagnosis is a key factor for the prognosis and the determination of appropriate treatment. Several cancer staging systems are used worldwide. The most useful staging system is the tumor, node and metastasis (TNM) staging system develop by the American Joint Committee on Cancer (AJCC) in collaboration with the Union for International Cancer Control (UICC) referred to as the AJCC TNM staging system. The AJCC TNM system classifies cancers by the size and extend of the primary tumor (T), involvement of regional lymph nodes (N) and the presence of distant metastases (M). AJCC and UICC periodically modify the AJCC TNM staging system according to newly acquired clinical, pathological and biological data improving understanding of cancer physiopathology. The 8th edition of AJCC TNM system is effective for cancer patients diagnosed on or after January 1, 2018. Here, we report the issues of the staging cancers of the oral cavity according to the 8th edition of AJCC TNM system. We focus on 2 new concepts defined in the 8th edition of AJCC TNM system: depth of invasion (DOI) and extranodal extension (ENE).

Cutaneous localization of angioimmunoblastic T-cell lymphoma may masquerade as B-cell lymphoma or classical Hodgkin lymphoma: A histologic diagnostic pitfall.

BACKGROUND: We report the cases of three patients presenting skin lesions whose biopsies showed nodular polymorphic infiltrates consisting of lymphocytes, plasma cells, histiocytes, eosinophils, B blasts, and Hodgkin Reed-Sternberg (HRS)-like cells. Two of them were initially diagnosed as classical Hodgkin lymphoma (cHL), on the other hand, the last one as a B-cell lymphoma. All patients have been treated for angioimmunoblastic T-cell lymphoma (AITL). METHODS: We performed a second review of the skin biopsies with further immunophenotypic molecular analyses. Scrupulous observation revealed, in the background of the three cases, atypical small to medium-sized lymphocytes carrying a CD3+, CD4+ T-cell phenotype and expressing PD1 and CXCL13 follicular helper T-cell markers. The two lesions initially diagnosed as cHL showed scattered HRS-like cells with CD30+, CD15+, PAX5+, CD20-, Epstein Barr Virus (EBV) + classical phenotype. The case initially diagnosed as B-cell lymphoma showed a diffuse B-cell proliferation associated with small B-cell and medium to large-sized B blasts that were positive for EBV. CONCLUSION: Those cases highlighted that atypical T-cells may be obscured by B-cell proliferation mimicking cHL or B-cell lymphoma in cutaneous localization of AITL and confirmed the requirement of collecting clinical information before performing a diagnosis.

Composite cutaneous lymphoma of diffuse large B-cell lymphoma-leg type and subcutaneous panniculitis-like T-cell lymphoma.

Composite lymphoma (CL) is a rare disease defined by the occurrence of two distinct lymphomas within a single tissue at the same time. We present the case of an 89-year-old male with a clinical history of immunoglobulin M monoclonal gammopathy of undetermined significance. The patient presented cutaneous eruption of nodules on the right bottom and arm. An excisional biopsy revealed cutaneous infiltration composed of two components. The first one consisted of large B-cells with CD20+/MUM1+/BCL2+ phenotype whereas the second one involved the subcutaneous fat in a panniculitic manner, and was CD3+/CD8+/granzyme B+/TCRßF1+. The final diagnosis was CL of primary cutaneous large B-cell lymphoma-leg type (PCLBCL-leg type) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL). We report and characterize for the first time coexistent PCLBCL-leg type and SPTCL in a patient.

Diagnostic value of STMN1, LMO2, HGAL, AID expression and 1p36 chromosomal abnormalities in primary cutaneous B cell lymphomas.

AIMS: Distinction between primary cutaneous follicular lymphoma (PCFL) and primary cutaneous marginal zone lymphoma (PCMZL) is challenging, as clear-cut immunophenotypical and cytogenetic criteria to segregate both entities are lacking. METHODS AND RESULTS: To characterize PCFL and PCMZL more clearly and to define criteria helpful for the differential diagnosis, we compared expression of immunohistochemical markers [LIM-only transcription factor 2 (LMO2), human germinal centre-associated lymphoma (HGAL), stathmin 1 (STMN1), activation-induced cytidine deaminase (AID), myeloid cell nuclear differentiation antigen (MNDA)] and the presence of cytogenetic abnormalities described previously in nodal follicular lymphoma [B cell lymphoma 2 (BCL2) and BCL6 breaks, 1p36 chromosomal region deletion (del 1p36)] in a series of 48 cutaneous follicular and marginal zone lymphomas [cutaneous follicular lymphoma (CFL) and cutaneous marginal zone lymphoma (CMZL)]. Immunostaining for STMN1, LMO2, HGAL and AID allowed the distinction between CFL and CMZL, and STMN1 was the most sensitive marker (100% CFL, 0% CMZL). LMO2, HGAL and AID were positive in 93.2%, 82.1% and 86.2% CFL (all CMZL-negative). MNDA was expressed in both entities without significant difference (10.3% CFL, 30.8% CMZL, P = 0.18). BCL2, BCL6 breaks and the del 1p36 were present in 16.7%, 10.7% and 18.5% CFL and no CMZL. Finally, three and 29 CFL were reclassified as secondary cutaneous follicular lymphomas (SCFL) and PCFL without significant differences concerning phenotypical and cytogenetic features. BCL2, BCL6 breaks and the del 1p36 were present in 11.1%, 8% and 16.7% PCFL and did not impact the prognosis. CONCLUSION: LMO2, HGAL, STMN1 and AID, but not MNDA, are discriminant for the recognition between CFL and CMZL. BCL2, BCL6 rearrangements and the del 1p36 have a role in the pathogenesis of PCFL, the latest being the most common alteration.

PD1 and PDL1 expression in primary central nervous system diffuse large B-cell lymphoma are frequent and expression of PD1 predicts poor survival.

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare and aggressive type of diffuse large B-cell lymphoma (DLBCL) whit poorly understood pathogenesis. Finding biomarkers associated with patient survival may be important for understanding its physiopathology and to develop new therapeutic approaches. We investigated 32 PCNS-DLBCL from immunocompetent patients for BCL2, CMYC, LMO2, and P53 expression and for cytogenetic aberrations of BCL2, BCL6, and MYC genes, all known for their prognostic value in systemic DLBCL (s-DLBCL). We analyzed PD1 and PDL1 protein expression in both tumor infiltrating lymphocytes (TILs) and tumor cells. Finally, we searched for correlation between biological data and clinical course. The PCNS-DLBCL expressed BCL2, CMYC, LMO2, and P53 at similar frequency than s-DLBCL but without significant prognostic on survival. None cases harbored aberrations involving BCL2 and MYC gene whereas BCL6 abnormalities were present in 20.7% of cases but without value on survival. Expression of PD1 in TILs and PDL1 in tumor cells was observed at higher rates than in s-DLBCL (58% and 37%, respectively). The PD1 expression in TILs correlated with PDL1 expression in tumor cells (P = .001). Presence of PD1 positive TILs was associated with poorer overall survival (P = .011). Patients with PDL1 overexpression tended to better response to chemotherapy (P = .23). In conclusion PCNS-DLBCL pathogenesis differs from s-DLBCL without prognostic value of the phenotypic and cytogenetic parameters known for their pejorative impact in the latter. The PD1/PDL1 pathway plays a strong role in PCNS-DLBCL and represents an attractive target for this aggressive lymphoma.

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.

Twelve years after: The french national network on rare head and neck tumours (REFCOR).

BACKGROUND: Rare cancers constitute less than 10% of head and neck cancers and lack sufficient evidence for standardized care. The French Rare Head and Neck Cancer Expert Network (REFCOR) as established a national database to collect data on these rare cancers. This study aims to describe patient and tumour characteristics in this database. METHODS: Prospective data collection was conducted across multiple centers. Survival analyses were performed using Kaplan Meier method and Log Rank test. Odds ratios were used for comparing proportions. RESULTS: A total of 7208 patients were included over a period of 10 years. The most frequent histologies were: Not Otherwise Specified (NOS) adenocarcinoma 13 %, adenoid cystic carcinoma 12 %, squamous cell carcinoma of rare locations 10 %, mucoepidermoid carcinoma 9 %, intestinal-type adenocarcinoma (8 %). Tumours were located in sinonasal area (38 %); salivary glands (32 %); oral cavity / oropharynx / nasopharynx (16 %); larynx / hypopharynx (3 %); ears (1 %); others (3 %). Tumours were predominantly classified as T4 (23 %), N0 (54 %), and M0 (62 %). Primary treatment approach involved tumour resection (78 %) and / or radiotherapy (63 %). Patients with salivary gland cancers exhibited better 5-year overall survival (OS) rates (p < 0.05), and lower recurrence rates compared to patients with sinonasal, laryngeal/ hypopharyngeal cancers. No significant differences were observed in the other comparisons. Acinar cell carcinoma demonstrated the best OS while mucous melanoma had the poorest prognosis. CONCLUSION: Melanoma, carcinoma NOS, and sinonasal undifferenciated carcinoma still have poor prognoses. Efforts are being made, including training and guidelines, to expand network coverage (REFCOR, EURACAN), improve data collection and contribute to personalized therapies.

Beneath HMGA2 alterations in Pleomorphic Adenomas: Pathological, Immunohistochemical, and Molecular Insights.

AIMS: Most salivary gland neoplasms are distinguished by specific recurrent gene fusions. Recently, a subset of pleomorphic adenomas (PAs) originated from the parotid gland harboring the HMGA2::WIF1 fusion was described with a canalicular adenoma-like morphology and a greater propensity for recurrence and carcinomatous transformation. METHODS AND RESULTS: This study delineates the clinicopathological attributes of 54 cases of PAs exhibiting HMGA2 alterations, predominantly characterized by the HMGA2::WIF1 fusion, alongside a comparative analysis of their morphological and immunohistochemical profiles. The cohort consisted of 23 females and 31 males (n=54), mean age was 56.7 (25-84), tumors predominantly originated from the parotid gland (94.4%, 51/54), with 3 cases from seromucous glands (5.6%). Mean tumor size was 2.6 cm (0.8-7.5). No clinical difference (demographic, follow-up) was observed among histological subsets (conventional, hybrid, and pure). Complete excision was performed in all cases, with follow-up data available for 41% (22/54) of patients, showing 13.6% of recurrence (3/22) between 5 and 8 months. Various histological growth patterns were identified, with the pure hypercellular monomorphic subset being the most prevalent. The HMGA2::WIF1 gene was identified in all subsets without any particular predominance. Novel gene partners of HMGA2 were identified, comprising NRXN1, INPP4B, MSRB3, PHLDA1, and FLJ41278. CONCLUSIONS: The present study reports that the HMGA2::WIF1 gene fusion was present in all subsets of PAs without significant predominance. However, further investigations are warranted to explore the relationship between histological subsets of PAs and the molecular alterations underlying them.

High-grade non-intestinal type sinonasal adenocarcinoma with ETV6::NTRK3 fusion, distinct from secretory carcinoma by immunoprofile and morphology.

We report 2 cases of high-grade sinonasal adenocarcinoma with a distinct morphological and immunohistochemical phenotype. Albeit histologically different from secretory carcinoma of the salivary glands, both tumors presented here share an ETV6::NTRK3 fusion. The highly cellular tumors were composed of solid and dense cribriform nests, often with comedo-like necroses in the center, and minor areas with papillary, microcystic, and trabecular formations without secretions, mostly located at the periphery of the lesion. The cells displayed high-grade features, with enlarged, crowded, and often vesicular nuclei with conspicuous nucleoli and brisk mitotic activity. The tumor cells were immunonegative for mammaglobin while showing immunopositivity for p40/p63, S100, SOX10, and GATA3, as well as for cytokeratins 7, 18, and 19. For the first time, we describe 2 cases of primary high-grade non-intestinal type adenocarcinomas of the nasal cavity, distinct from secretory carcinoma by morphology and immunoprofile, harboring the ETV6::NTRK3 fusion.

[Rare cancers of the head and neck on behalf of the REFCOR, part 2]. / Cancers rares de la tête et du cou sous l'égide du REFCOR, partie 2.

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology as well as their anatomical location when arising from the paranasal sinuses, salivary glands and ear. The management of these heterogeneous rare diseases of complex treatment has considerably been structured over the last 15 years, in particular via the French ENT Cancer Expertise Network (REFCOR) and international networks and registries (EURACAN, etc.). Structuration also favors research with identification of new entities and setting up of specific therapeutic trials. A first article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the REFCOR concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. This second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

[Rare cancers of the head and neck on behalf of the REFCOR, part 1]. / Cancers rares de la tête et du cou sous l'égide du REFCOR, partie 1.

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology, which determines their local invasiveness, and their hematogenous/nodal spread. Their diagnosis can be difficult and often requires comprehensive immunohistochemistry and genomic techniques. Expert pathology review is recommended in the cases of undifferentiated tumors, sarcomas and at the slightest diagnostic doubt. These rare cancers can also be rare by their anatomical location when arising from the paranasal sinuses, salivary glands and ear. Their location requires knowledge of their specific extension routes, and may call for a specific surgical technique (skull base endoscopic sinus surgery, extended total parotidectomy, etc.) and adapted radiotherapy to spare healthy organs surrounding the tumor. This article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the French ENT Cancer Expertise Network (REFCOR) concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. A second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

Sclerosing Polycystic Adenoma of Salivary Glands: A Novel Neoplasm Characterized by PI3K-AKT Pathway Alterations-New Insights Into a Challenging Entity.

Sclerosing polycystic adenoma (SPA) is a rare salivary gland neoplasm originally thought to represent a non-neoplastic lesion. Recently we have encountered an index case of apocrine intraductal carcinoma of parotid gland of 62-year-old man with invasive salivary duct carcinoma component arising from SPA, a combination of tumor entities that has never been published so far. Here, we further explore the nature of SPA by evaluating 36 cases that were identified from the authors' consultation files. The patients were 25 females and 11 males aged 11 to 79 years (mean, 47.8 y). All tumors originated from the parotid gland. Their size ranged from 11 to 70 mm (mean, 28 mm). Histologically, all cases revealed characteristic features of SPA, such as lobulated well-circumscribed growth, focal hyalinized sclerosis, presence of large acinar cells with abundant brightly eosinophilic intracytoplasmic granules, and ductal components with variable cytomorphologic characteristics, including foamy, vacuolated, apocrine, mucous, clear/ballooned, squamous, columnar and oncocyte-like cells. In all cases, there were foci of intraluminal solid and cribriform intercalated duct-like epithelial proliferations with variable dysplasia which were positive for S100 protein and SOX10, and fully enveloped by an intact layer of myoepithelial cells. In addition, 14/36 cases (39%) had focal intraductal cribriform and micropapillary apocrine-type dysplastic epithelial structures composed of cells positive for androgen receptors and negative for S100/SOX10. The intraductal proliferations of both types showed focal mild to severe dysplasia in 17 cases (17/36; 47%). Two cases showed overt malignant morphology ranging from high-grade intraductal carcinoma to invasive carcinoma with an apocrine ductal phenotype. Next generation sequencing using ArcherDX panel targeting RNA of 36 pan-cancer-related genes and/or a TruSight Oncology 170/500 Kit targeting a selection of DNA from 523 genes and RNA from 55 genes was performed. Tumor tissue was available for molecular analysis in 11 cases, and 9 (9/11; 82%) of them harbored genetic alterations in the PI3K pathway. Targeted sequencing revealed HRAS mutations c.37G>C, p.(Gly13Arg) (2 cases) and c.182A>G, p.(Gln61Arg) (2 cases), and PIK3CA mutations c.3140A>G, p.(His1047Arg) (3 cases), c.1633G>A, p.(Glu545Lys) (1 case), and c.1624G>A, p.(Glu542Lys) (1 case). Moreover, mutations in AKT1 c.49G>A, p.(Glu17Lys) and c.51dup, p.(Tyr18ValfsTer15); c.49_50delinsAG, p.(Glu17Arg) (as a double hit) were found (2 cases). In addition, germinal and somatic mutation of PTEN c.1003C>T, p.(Arg335Ter); c.445C>T, p.(Gln149Ter), respectively, were detected. Gene fusions were absent in all cases. These prevalent molecular alterations converging on one major cancer-related pathway support the notion that SPA is a true neoplasm with a significant potential to develop intraluminal epithelial proliferation with apocrine and/or intercalated duct-like phenotype. The name SPA more correctly reflects the true neoplastic nature of this enigmatic lesion.