Expanding the Molecular Spectrum of Secretory Carcinoma of Salivary Glands With a Novel VIM-RET Fusion

Insights Into Pediatric Secretory Carcinoma of the Salivary Gland: A Case Report

Secretory carcinoma of the salivary gland (SCSG) is a rare head and neck tumor in adults and exceptional at the pediatric age. Its varied histological subtypes and distinct clinical presentation pose diagnostic and therapeutic challenges. Therefore, standardized guidelines are of utmost importance for the care of these patients, especially in children. Here we present an 11-year-old male presented with a left cheek mass initially diagnosed as lipoma. A wide resection was performed and SCSG was revealed in the histopathologic and immunohistochemistry analysis. The presentation of this case provides valuable information on the diagnostic and therapeutic complexities of SCSG. It emphasizes the need for standardized guidelines and further research to optimize pediatric patient outcomes. Overall, this case report is a crucial resource for clinicians and researchers, highlighting the importance of interdisciplinary collaboration and early intervention in managing SCSG.

Molecular testing in salivary gland cytopathology: A practical overview in conjunction with the Milan system

Recently, significant advances in the molecular characterization of salivary gland neoplasms have facilitated the classification and diagnosis of specific diagnostic entities. In the highly challenging diagnostic scenario of salivary malignancies, molecular testing is increasingly being adopted in routine practice to refine the cytological diagnosis of salivary lesions. Here, we reviewed the most recent evidence in the field of salivary glands molecular cytopathology.

[Fusion genes in salivary gland tumors]

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.

Molecular pathology in diagnosis and prognostication of head and neck tumors

Classification of head and neck tumors has evolved in recent decades including a widespread application of molecular testing in tumors of the salivary glands, sinonasal tract, oropharynx, nasopharynx, and soft tissue. Availability of new molecular techniques allowed for the definition of multiple novel tumor types unique to head and neck sites. Moreover, the expanding spectrum of immunohistochemical markers facilitates a rapid identification of diagnostic molecular abnormalities. As such, it is currently possible for head and neck pathologists to benefit from a molecularly defined classifications, while making diagnoses that are still based largely on histopathology and immunohistochemistry. This review highlights some principal molecular alterations in head and neck neoplasms presently available to assist pathologists in the practice of diagnosis, prognostication and prediction of response to treatment.

Clinicopathological analysis of 18 cases of secretory carcinoma of the salivary glands

Background/purpose

Secretory carcinoma (SC) is a rare salivary gland tumor that featured by ETV6::NTRK3 gene fusion, and was included in the WHO Classification of Head and Neck Tumors since 2017. Nevertheless, the description of SCs by WHO is still vague. This study examined 18 SC cases by using both histomorphology and molecular pathology for diagnostic determination, especially immunohistochemical features of SCs.

Materials and methods

Based on WHO characteristics, 18 patients with SC admitted between 2001 and 2022 were included in this study. Main histomorphological patterns, FISH analyses of the ETV6::NTRK3 gene fusion, and immunohistochemical analyses of S100, mammaglobin, DOG1, ADFP, CA6 and Ki-67 were performed.

Results

Among the 18 SC patients, the median age of onset was 39.22 years. Grossly, the average tumor size in 2.96 cm with various texture from soft to tough. The majority patients were positive for S100, mammaglobin, and negative for DOG1, except for one patient negative for S100 (Case 18). All patients were positive for ADFP, and the majority patients were negative for CA6, except for Case 9. Two cases were found recurrence, and the tumor were found both in parotid gland with local invasion.

Conclusion

Combined with the results of previous studies, we proposed that the combination of all five markers, S100, mammaglobin, DOG1, ADFP and CA6, could contribute more to differential diagnosis of SCs with other salivary carcinomas, especially with AciCC. The prognosis of SCs is optimistic in most cases, but larger patient cohort and long-term follow-up are still needed.

Recent developments in the pathology of primary pulmonary salivary gland-type tumours

Primary pulmonary salivary gland-type tumours are rare neoplasms that are thought to arise from seromucinous glands that are located in the submucosa of large airways. These neoplasms have clinical and pathologic features that are distinct from other pulmonary neoplasms. The majority of primary pulmonary salivary gland-type tumours are malignant, with the most common entities being mucoepidermoid carcinoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma. Less commonly seen are myoepithelial carcinoma, hyalinizing clear cell carcinoma, acinic cell carcinoma, secretory carcinoma, salivary duct carcinoma, intraductal carcinoma, and polymorphous adenocarcinoma. Benign salivary gland-type tumours of the lung include pleomorphic adenoma and sialadenoma papilliferum. Morphologic, immunophenotypic, and molecular features of these neoplasms are largely similar to salivary gland tumours elsewhere, and therefore the exclusion of metastatic disease requires clinical and radiologic correlation. However, the differential diagnostic considerations are different in the lung. The distinction of salivary gland-type tumours from their histologic mimics is important for both prognostication and treatment decisions. Overall, salivary gland type-tumours tend to have a more favourable outcome than other pulmonary carcinomas, although high-grade variants exist for many of these tumour types. Recent advances in our understanding of the spectrum of salivary gland-type tumours reported in the lung and their diversity of molecular and immunohistochemical features have helped to refine the classification of these tumours and have highlighted a few differences between salivary gland-type tumours of the lung and those primary to other sites.

Utility of MUC4 in the diagnosis of secretory carcinoma of salivary glands

Salivary gland tumors are diverse in morphology and both benign and malignant tumors may pose diagnostic challenges especially in small biopsies. Secretory carcinoma (SC) is histologically characterized by microcysts, follicles, solid growth pattern and occasional papillary structures, and absence of zymogen granules. SC is molecularly defined by the presence of novel gene fusion ETV6::NTRK3. Among the positive stains (S100 and mammaglobin), MUC4 is now another promising marker for the diagnosis of SC, that would enable the pathologists to exclude other morphologically close simulators. Aim of this study was to report clinicopathological features and assess utility of MUC4 in the diagnosis of SC. MUC4 was performed on 22 cases of SC. Glass slides were reviewed to record morphological patterns and staining of S100, mammaglobin, DOG1 and MUC4. Age ranged from 9 to 63 years with mean age of 34.41 ± 16.28 years. The male: female ratio was 72.7 %:27.3 %. The majority occurred in major salivary glands. A combination of patterns was seen; microfollicles were the most prevalent (90 %) followed by papillary-cystic and macrofollicles. MUC4 was positive in 19/21 (90 %) cases with almost equal number of 2+ and 3+ staining. MUC4 was negative in all cases of acinic cell carcinoma, polymorphous adenocarcinoma, adenoid cystic carcinoma, salivary duct carcinoma, myopepithelioma and myoeithelial carcinoma, cystadenoma and cribriform adenocarcinoma and all except 3 cases of mucoepidermoid carcinoma tested. Overall sensitivity of MUC4 was 95.4 %, specificity 90 %, p-value being <0.01, positive predictive value 87.5 % and negative predictive value 96.4 %. A characteristic cytoplasmic granular pattern was observed in 76.1 % tumors. S100 and mammaglobin were positive in all the performed cases. DOG1 was positive in 6/11 (28.5 %) tumors. In conclusion, MUC4 is a useful addition to a diagnostic immunohistochemical panel for SC, and to distinguish it from close potential mimickers such as acinic cell carcinoma, especially in practice settings where molecular testing is unavailable.

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.

Defining the clinical characteristics of mammary analog secretory carcinoma of the salivary gland: Analysis of the National Cancer Database

Objectives

Mammary analog secretory carcinoma (MASC) is a classification of salivary gland tumors, recently included within the term secretory carcinoma. Previous descriptions of this diagnosis have largely consisted of case reports and case series with few studies investigating its clinical characteristics as compared to non-MASC tumors. Our objective was to use a large patient database to compare the clinical characteristics of mammary analog secretory carcinoma vs. non-mammary analog secretory carcinoma salivary gland tumors.

Methods

The National Cancer Database was queried between September and October 2022 for histological diagnosis of mammary analog secretory carcinoma and non-MASC salivary tumors. Patients diagnosed with mammary analog secretory carcinoma and non-mammary analog secretory carcinoma salivary tumors between the period of 2004 through 2019 were included in this analysis. Various demographic and clinical variables were abstracted from the database and compared using Wilcoxon rank sum and chi-square tests. Survival was compared between cohorts using Cox proportional hazards regression.

Results

Overall, compared to non-mammary analog secretory carcinoma diagnoses (n = 47668), mammary analog secretory carcinoma tumors (n = 384) affected younger individuals, displayed favorable pathologic staging and tumor grade, and were less likely to invade surrounding tissues. Patients with mammary analog secretory carcinoma tumors also received treatment more quickly following diagnosis compared to patients with non-mammary analog secretory carcinoma tumors. The risk of death was 4.3 times greater for non-mammary analog secretory carcinoma diagnoses when adjusted for patient variables (hazard ratio = 4.3, 95% confidence interval [2.37-7.71], p < 0.001).

Conclusions

Clinically, mammary analog secretory carcinoma salivary tumors have a more indolent course compared to other salivary cancers. Additional studies are needed to determine the natural history of this tumor type.

Salivary gland neoplasms in small biopsies and fine needle aspirations

Salivary gland neoplasms are rare and represent a diverse group of head and neck tumors. Their diagnosis in limited cellularity specimens can be challenging as many of these have overlapping clinical, radiological presentation, and pathologic features. Fine needle aspiration and/or core biopsies are more of a norm than rarity to be performed preoperatively to provide invaluable information that can guide clinical management including surgery. Even though these limited specimens may not always provide a definitive diagnosis; they have high sensitivity in confirming primary neoplasia, assessing the tumor grade, and ruling out non-surgical disease. An algorithmic pattern based approach can help narrow the differential diagnosis; leading to a definitive diagnosis with the help of specific ancillary studies.

RET-Altered Cancers-A Tumor-Agnostic Review of Biology, Diagnosis and Targeted Therapy Activity

RET alterations, such as fusions or mutations, drive the growth of multiple tumor types. These alterations are found in canonical (lung and thyroid) and non-canonical (e.g., gastrointestinal, breast, gynecological, genitourinary, histiocytic) cancers. RET alterations are best identified via comprehensive next-generation sequencing, preferably with DNA and RNA interrogation for fusions. Targeted therapies for RET-dependent cancers have evolved from older multikinase inhibitors to selective inhibitors of RET such as selpercatinib and pralsetinib. Prospective basket trials and retrospective reports have demonstrated the activity of these drugs in a wide variety of RET-altered cancers, notably those with RET fusions. This paved the way for the first tumor-agnostic selective RET inhibitor US FDA approval in 2022. Acquired resistance to RET kinase inhibitors can take the form of acquired resistance mutations (e.g., RET G810X) or bypass alterations.

Salivary Gland Secretory Carcinoma: Clinicopathologic and Genetic Characteristics of 215 Cases and Proposal for a Grading System

Salivary gland secretory carcinoma (SC), previously mammary analog SC, is a low-grade malignancy characterized by well-defined morphology and an immunohistochemical and genetic profile identical to SC of the breast. Translocation t(12;15)(p13;q25) resulting in the ETV6 :: NTRK3 gene fusion is a characteristic feature of SC along with S100 protein and mammaglobin immunopositivity. The spectrum of genetic alterations for SC continues to evolve. The aim of this retrospective study was to collect data of salivary gland SCs and to correlate their histologic, immunohistochemical, and molecular genetic data with clinical behavior and long-term follow-up. In this large retrospective study, we aimed to establish a histologic grading scheme and scoring system. A total of 215 cases of salivary gland SCs diagnosed between 1994 and 2021 were obtained from the tumor registries of the authors. Eighty cases were originally diagnosed as something other than SC, most frequently acinic cell carcinoma. Lymph node metastases were identified in 17.1% (20/117 cases with available data), with distant metastasis in 5.1% (6/117). Disease recurrence was seen in 15% (n=17/113 cases with available data). The molecular genetic profile showed ETV6 :: NTRK3 gene fusion in 95.4%, including 1 case with a dual fusion of ETV6 :: NTRK3 and MYB :: SMR3B . Less frequent fusion transcripts included ETV6 :: RET (n=12) and VIM :: RET (n=1). A 3-tiered grading scheme using 6 pathologic parameters (prevailing architecture, pleomorphism, tumor necrosis, perineural invasion (PNI), lymphovascular invasion (LVI), and mitotic count and/or Ki-67 labeling index) was applied. Grade 1 histology was observed in 44.7% (n=96), grade 2 in 41.9% (n=90), and grade 3 in 13.5% (n=29) of cases. Compared with low-grade and intermediate-grade SC, high-grade tumors were associated with a solid architecture, more prominent hyalinization, infiltrative tumor borders, nuclear pleomorphism, presence of PNI and/or LVI, and Ki-67 proliferative index >30%. High-grade transformation, a subset of grade 2 or 3 tumors, seen in 8.8% (n=19), was defined as an abrupt transformation of conventional SC into high-grade morphology, sheet-like growth, and a tumor lacking distinctive features of SC. Both overall survival and disease-free survival (5 and 10 y) were negatively affected by tumor grade, stage, and TNM status (each P <0.0001). SC is a low-grade malignancy with predominantly solid-microcystic growth patterns, driven by a gene fusion, most commonly ETV6 :: NTRK3 . There is a low risk for local recurrence and a good overall long-term survival, with a low risk for distant metastasis but a higher risk for locoregional lymph node metastasis. The presence of tumor necrosis, hyalinization, PNI and/or LVI, and positive resection margins correlate with higher tumor grade, less favorable prognosis, and increased mortality. The statistical results allowed us to design a 3-tiered grading system for salivary SC.

Secretory carcinoma of minor salivary glands of buccal mucosa: A case report and review of the literature

INTRODUCTION AND IMPORTANCE

Secretory carcinoma (SC) is an uncommon salivary gland neoplasm of the oral cavity that microscopically may mimic acinic cell carcinoma (ACC) and mucoepidermoid carcinoma (MEC). Secretory carcinoma (SC) of the salivary gland has been recently added in fourth edition of the head and neck world health organization. Most of these tumors are located on the parotid gland with very few cases reported in the minor salivary glands of the buccal mucosa. This work has been reported in line with the SCARE criteria.

PRESENTATION OF CASE

A 42 years old hypertensive male, shop keeper by occupation, with no prior addiction history, no dental extraction or trauma, presented with complaint of nodular lesion on left buccal mucosa for five years. On Clinical examination, adequate mouth opening, dentulous patient with 2.4 × 2 cm well circumscribed, nodular, non-tender, benign looking lesion was observed on left buccal mucosa near upper alveolus. Overlying mucosa appeared normal with no clinically palpable cervical lymphadenopathy. Histopathology revealed salivary gland neoplasm favoring secretory carcinoma. MRI scan showed lobulated enhancing nodular lesion arising from left buccal mucosa of size 2.3 ∗ 1.3 ∗ 1.7 cm, close to left superior alveolus without involving any cortical areas of marrow infiltration, with bilateral symmetrical level IIa reactive cervical nodes. Wide local excision and ipsilateral selective neck dissection [level 1, 2, 3] was done. Post-operative period was smooth with no complain of paresthesia observed. The final histopathology report showed secretory carcinoma. Two out of six lymph nodes from level I were positive for metastatic carcinoma with no extra nodal extension. Final stage of the tumor was pT1N2bMx. Patient underwent post-operative adjuvant radiotherapy for period of 6 weeks, received total 30 fractions and total dose of 6000 centigray.

CLINICAL DISCUSSION

SC behaved clinically an indolent being painless and having long duration of symptoms with normal overlying mucosa. But histopathologically there was cervical node metastasis. That changed final staging and added adjuvant treatment for this patient. The discrepancy in clinical and pathological diagnosis might be due to the indolent clinical behavior of SC arising in the minor salivary gland of buccal mucosa. In the present case, the absence of zymogen granules and presence of microcytic pattern with eosinophilic cytoplasm and eosinophilic secretory material were suggestive of SC.

CONCLUSION

This case report represents a rare case of SC of minor salivary glands of buccal mucosa, which was indolent as per clinical presentation but on final histopathological report it had cervical nodal metastasis that changed the final stage of the disease, for which adjuvant radiotherapy was needed. Although Secretory carcinomas are generally considered having a favorable prognosis and are regarded as low- grade carcinomas with limited number of recurrence and cervical nodal metastasis, but sometimes they do metastasize to cervical nodes for which accurate and timely intervention in the form of neck dissection may be performed to establish final staging and start additional treatment modality if required for better outcome of the disease.

NTRK fusions in solid tumours: what every pathologist needs to know

Fusions involving the Neurotrophic tropomyosin receptor kinase (NTRK) gene family (NTRK1, NTRK2 and NTRK3) are targetable oncogenic alterations that are found in a diverse range of tumours. There is an increasing demand to identify tumours which harbour these fusions to enable treatment with selective tyrosine kinase inhibitors such as larotrectinib and entrectinib. NTRK fusions occur in a wide range of tumours including rare tumours such as infantile fibrosarcoma and secretory carcinomas of the salivary gland and breast, as well as at low frequencies in more common tumours including melanoma, colorectal, thyroid and lung carcinomas. Identifying NTRK fusions is a challenging task given the different genetic mechanisms underlying NTRK fusions, their varying frequency across different tumour types, complicated by other factors such as tissue availability, optimal detection methods, accessibility and costs of testing methods. Pathologists play a key role in navigating through these complexities by determining optimal approaches to NTRK testing which has important therapeutic and prognostic implications. This review provides an overview of tumours harbouring NTRK fusions, the importance of identifying these fusions, available testing methods including advantages and limitations, and generalised and tumour-specific approaches to testing.

Diagnostic accuracy of pan-TRK immunohistochemistry in differentiating secretory carcinoma from acinic cell carcinoma of salivary gland-A systematic review

BACKGROUND

Secretory carcinoma (SC) is a well-established salivary gland malignancy that has earned its popularity for its unique clinicopathological behavior. Although it is an indolent malignancy, few of them have been reported with high grade transformation making it mandatory to differentiate it from its prime histological mimicker, acinic cell carcinoma (AciCC). Recently, many studies have been directed toward validating the sensitivity and specificity of pan-TRK IHC for confirming ETV6::NTRK3 gene fusion in SCs involving salivary gland.

AIM

The aim of the present systematic review was to establish the diagnostic utility of pan-TRK immunostaining in histological differentiation of SC from AciCC.

MATERIAL AND METHODS

An electronic search was carried out using MEDLINE by PubMed, Scopus, Google scholar, Trip, Cochrane library and EMBASE databases. Articles in which SC assessed with pan-TRK immunohistochemical expressions were included for systematic review and their staining pattern (cytoplasmic, nuclear and/or combined), sensitivity, specificity, positive as well as negative predictive were gathered. Risk of bias was analyzed for each study using QUADAS-2 tool.

RESULTS

Thirteen eligible articles were included for the quantitative analysis, which revealed positive immunostaining of pan-TRK by nearly all the ETV6::NTRK3 fusion prevalent SCs alongside negative expression in almost all the cases of AciCC with 100% of sensitivity as well as specificity.

CONCLUSION

The evidence from the included studies supports that pan-TRK immunostaining could be used as a reliable preliminary screening tool for discerning SC from AciCC. PROSPERO No: CRD42022308913.

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). Six tumours were low-grade, two intermediate-grade, one high-grade, and one demonstrated low-grade areas with high-grade transformation. Four cases were oncocytic, four had clear-cell features, two had spindle cell features, and one high-grade MEC had prominent solid, cord-like, and micropapillary features. The tumours were negative for p40 (10/10), p63 (10/10), and CK5/6 (9/9). Targeted RNA sequencing demonstrated CRTC1::MAML2 in five cases, CRTC3::MAML2 in two, and a novel MAML2::CEP126 in the unusual high-grade case. In two cases with insufficient RNA, MAML2 fluorescence in situ hybridisation (FISH) showed rearrangement. Genetically-confirmed MEC may lack overt squamous differentiation by histology and immunohistochemistry. While most cases harboured canonical fusions and fit within the spectra of MEC variants with oncocytic, clear cell, and/or spindle cell features, one had a novel MAML2::CEP126 fusion and unusual morphology. In MEC without squamoid cells, the use of immunohistochemistry may hinder, rather than aid, the correct diagnosis. In such cases, MAML2 analysis is most useful. The historical definition of MEC as a carcinoma with squamoid, intermediate and mucous cells should be revisited.

Maximizing Small Biopsy Patient Samples: Unified RNA-Seq Platform Assessment of over 120,000 Patient Biopsies

Despite its wide-ranging benefits, whole-transcriptome or RNA exome profiling is challenging to implement in a clinical diagnostic setting. The Unified Assay is a comprehensive workflow wherein exome-enriched RNA-sequencing (RNA-Seq) assays are performed on clinical samples and analyzed by a series of advanced machine learning-based classifiers. Gene expression signatures and rare and/or novel genomic events, including fusions, mitochondrial variants, and loss of heterozygosity were assessed using RNA-Seq data generated from 120,313 clinical samples across three clinical indications (thyroid cancer, lung cancer, and interstitial lung disease). Since its implementation, the data derived from the Unified Assay have allowed significantly more patients to avoid unnecessary diagnostic surgery and have played an important role in guiding follow-up decisions regarding treatment. Collectively, data from the Unified Assay show the utility of RNA-Seq and RNA expression signatures in the clinical laboratory, and their importance to the future of precision medicine.

Molecular identification of an ETV6-RET fusion in a secretory carcinoma associated with a pleomorphic adenoma

Pleomorphic adenoma (PA) is the most common neoplasm of the salivary glands. Although several carcinomas have been reported to arise from PA, only 1 case of salivary gland secretory carcinoma (SC) ex pleomorphic adenoma has been previously reported. SC is a newly described salivary gland tumor harboring an ETV6-NTRK3 translocation, which is classically observed in secretory carcinoma of the breast, although other translocations have recently been observed. We report the first case of the molecular identification of a rare ETV6-RET translocation in an SC arising from a PA in the submandibular salivary gland (SC ex PA). Our results add to the diversity of tumors that are associated with PA and contribute to the molecular characterization of SC, which will have implications on its diagnosis, prognosis, and treatment.

Secretory carcinoma of the sinonasal cavity and pharynx: A retrospective analysis of four cases and literature review

Secretory carcinoma (SC) is a recently recognized type of salivary gland tumor characterized by t(12;15) (p13;q25) translocation resulting in an ETV6-NTRK3 gene fusion. Most SCs are located in a main salivary gland, and primary sinonasal secretary carcinoma is rare. We describe three cases of primary SC in the sinonasal cavity with high-grade transformation (HGT) in one case, and the first case in the pharynx. All tumors comprised slightly atypical cells with solid, tubular, microcystic growth patterns. The case with HGT included two components with distinct sharp boundaries and comedo necrosis, high mitotic figures and obvious cellular atypia. Tumor cells were positive for vimentin, S100, and Gata-3 and negative for p63 and DOG-1. Three cases showed nuclear staining of pan-TRK and one showed cytoplasmic staining. All cases harbored ETV6 gene rearrangement, and ETV6-NTRK3 gene fusion was detected in three cases. Most patients were treated with radical resection and adjuvant therapy. After excision, all remained tumor-free for 65-164 months (medium 98.5 months). SC in the sinonasal cavity and pharynx is a low-grade malignant tumor with histologic features overlapping those of other salivary gland tumors. Immunohistochemical analysis and fluorescence in situ hybridization are useful techniques for its differential diagnosis.

A Pediatric Case of High-Grade Secretory Carcinoma of the Maxillary Sinus With ETV6::NTRK3 Gene Fusion, Therapeutic Implications, and Review of the Literature

Secretory carcinoma (SC) is a salivary gland tumor with a generally low grade microscopic appearance, a characteristic immunophenotype, and a recurrent translocation leading to ETV6::NTRK3 fusion gene. Rare cases are reported in children. The maxillary sinus is an unusual localization. SC have an overall favorable prognosis, but cases with high grade morphology have been described in adult population and are related to a more aggressive clinical course. We present a pediatric case of secretory carcinoma involving the maxillary sinus with high grade morphology, with a review of the literature of secretory carcinomas with high grade component.

Salivary gland cancers in elderly patients: challenges and therapeutic strategies

Salivary gland carcinomas (SGCs) are the most heterogeneous subgroup of head and neck malignant tumors, accounting for more than 20 subtypes. The median age of SGC diagnosis is expected to rise in the following decades, leading to crucial clinical challenges in geriatric oncology. Elderly patients, in comparison with patients aged below 65 years, are generally considered less amenable to receiving state-of-the-art curative treatments for localized disease, such as surgery and radiation/particle therapy. In the advanced setting, chemotherapy regimens are often dampened by the consideration of cardiovascular and renal comorbidities. Nevertheless, the elderly population encompasses a broad spectrum of functionalities. In the last decades, some screening tools (e.g. the G8 questionnaire) have been developed to identify those subjects who should receive a multidimensional geriatric assessment, to answer the question about the feasibility of complex treatments. In the present article, we discuss the most frequent SGC histologies diagnosed in the elderly population and the relative 5-years survival outcomes based on the most recent data from the Surveillance, Epidemiology, and End Results (SEER) Program. Moreover, we review the therapeutic strategies currently available for locoregionally advanced and metastatic disease, taking into account the recent advances in precision oncology. The synergy between the Multidisciplinary Tumor Board and the Geriatrician aims to shape the most appropriate treatment pathway for each elderly patient, focusing on global functionality instead of the sole chronological age.

Advancement of secretory breast carcinoma: a narrative review

BACKGROUND AND OBJECTIVE

Secretory breast carcinoma (SBC) is a rare breast malignancy. Most available studies on SBC are case reports or small case series, and the few large-sample studies available lack critical information due to database limitations. To improve the understanding of SBC and provide a reference for clinical practice, we systematically reviewed the demographic, clinical, pathologic, and genetic characteristics of SBC, as well as its treatment and prognosis.

METHODS

We conducted a PubMed search with the keywords "secretory breast carcinoma" or "juvenile breast carcinoma". Relevant English-language publications published from January 1966 to February 2022 were screened manually at 3 levels-title, abstract, and full text-to identify the articles that presented the demographic, clinical, pathologic, and genetic characteristics of SBC, as well as its treatment and prognosis.

KEY CONTENT AND FINDINGS

SBC lacks specific clinical manifestations and has typical pathological and molecular characteristics, including intracellular and extracellular eosinophilic secretions, immune spectrum similar to hormone receptor-positive tumors, and the ETV6-NTRK3 fusion gene. Surgery remains the primary treatment for SBC. Postoperative radiotherapy is recommended by most researchers for adult SBC but not for pediatric patients. The evidence of chemotherapy and endocrine therapy is insufficient, and targeted therapy of the ETV6-NTRK3 fusion gene shows a good response. Most patients with SBC have a good prognosis except for a few patients who experience distant metastases. Future studies will be focused on the molecular characteristics of those patients with SBC who have a poor prognosis.

CONCLUSIONS

The development of histopathology and molecular genetics has promoted the progress of the clinical diagnosis of SBC. The purpose of this review is to serve as a guide for the better clinical treatment of SBC, particularly in the areas of disease identification and prognosis classification for patients.

Secretory carcinoma of the salivary gland: a multi-institutional clinicopathologic study of 90 cases with emphasis on grading and prognostic factors

Secretory carcinoma (SC) is a rare form of salivary carcinoma that was first described in 2010 and is characterized by ETV6::NTRK3 fusion in most cases. In this large retrospective study, we aimed to identify adverse clinicopathologic factors and propose a prognostically relevant grading scheme for SC.

METHODS

A detailed clinicopathologic review was conducted on 90 SCs from the major and minor salivary glands.

RESULTS

The median age at presentation was 50 years (range: 7-93). Sixty-nine (77%) tumours originated from major salivary glands, whereas the remaining 21 involved minor salivary glands.Six cases (7%) had cervical nodal metastasis. Only lymphovascular invasion (LVI) was associated with a risk of nodal metastasis (P < 0.05). The 5-year disease-specific survival and disease-free survival (DFS) were 98% and 87%, respectively. On univariate survival analysis, adverse prognostic factors associated with decreased DFS included minor salivary gland origin, atypical mitosis, high mitotic index, high-grade transformation (HGT), necrosis, nuclear pleomorphism, infiltrative tumour border, fibrosis at the invasive front, LVI, positive margin, and advanced pT stage (P < 0.05). When adjusted for pT stage and margin status, mitotic index, LVI, nuclear pleomorphism, and HGT remained as independent prognostic factors.

CONCLUSION

We therefore propose a two-tiered grading system for SC. The low-grade SC is defined as those with <5 mitoses /10 high-power fields and no tumour necrosis, and high-grade SC as those with ≥5 mitoses /10 high-power fields and/or necrosis. This proposed grading system can be useful to risk stratify patients with SC for appropriate clinical management.

Molecular testing of cytology specimens: overview of assay selection with focus on lung, salivary gland, and thyroid testing

Ancillary and molecular testing of cytopathology specimens has emerged as a reliable and useful tool to provide diagnostic information and treatment-related biomarker status for the management of cancer patients. The cytology specimens obtained through minimally invasive means have proven suitable testing substrates for a variety of ancillary tests, including immunohistochemistry, fluorescence in situ hybridization, as well as polymerase chain reaction and next generation sequencing molecular techniques. By focusing specifically on the cytology specimen, this review provides an overview of basic testing considerations and assay selection in addition to updates on the ancillary testing of cytologic tumor specimens from the lung, salivary gland, and thyroid.

Numerical aspects of thermo migrated radiative nanofluid flow towards a moving wedge with combined magnetic force and porous medium

The researchers are continuously working on nanomaterials and exploring many multidisciplinary applications in thermal engineering, biomedical and industrial systems. In current problem, the analytical simulations for performed for thermos-migration flow of nanofluid subject to the thermal radiation and porous media. The moving wedge endorsed the flow pattern. The heat source effects are also utilized to improves the heat transfer rate. The applications of thermophoresis phenomenon are addressed. The formulated set of expressions are analytically treated with implementation of variational iteration method (VIM). The simulations are verified by making the comparison the numerical date with existing literature. The VIM analytical can effectively tackle the nonlinear coupled flow system effectively. The physical impact for flow regime due to different parameters is highlighted. Moreover, the numerical outcomes are listed for Nusselt number.

Secretory Carcinoma of the Salivary Gland: A Rarity in Children

Originally described as mammary analog secretory carcinoma (SC), SC of the salivary gland is a rare malignancy with morphologic and molecular similarities to SC of the breast. We present 2 children with salivary gland SC with the classic ETV6-NTRK3 gene fusion, including 1 with lymph node metastases. Both patients underwent surgical resection and were in remission 24 months postsurgery. One patient was additionally found to have synchronous papillary thyroid carcinoma with a TFG-MET fusion. A review of published cases highlights the expanding molecular profile and confirms the favorable course of salivary gland SC after surgical resection.

Secretory carcinoma of the salivary gland, a rare entity: An international multi-institutional study

BACKGROUND

Secretory carcinoma (SC) of the salivary gland is a rare entity with limited published literature on cytomorphology. The authors present the largest cohort to date of SC fine‐needle aspiration (FNA) cases.

METHODS

FNA cases of histologically confirmed SC were retrospectively retrieved from 12 academic institutions in the United States, Italy, Finland, and Brazil. The collated data included patient demographics, imaging findings, cytopathologic diagnoses according to the Milan System for Reporting Salivary Gland Cytopathology, cytomorphologic characteristics, and immunohistochemical/molecular profiles.

RESULTS

In total, 40 SCs were identified (male‐to‐female ratio, 14:26) in patients with a mean age of 52 years (age range, 13‐80 years). Ultrasound imagining revealed a hypoechoic, ovoid, poorly defined, or lobulated mass. The most common primary site was the parotid gland (30 of 40 tumors). Regional lymph node metastasis (9 patients) and distant metastasis (4 patients; brain, liver, lungs, and mediastinum) were noted. Two patients died of disease. FNA smears were cellular and demonstrated mainly large, round cells with intracytoplasmic vacuoles or granules and round‐to‐oval nuclei with smooth nuclear contour, minimal irregularities, and prominent nucleoli arranged predominantly in clusters, papillary formations, and single cells. The background was variable and contained inflammatory cells, mucin, or proteinaceous material. The diagnoses were malignant (19 of 38 tumors; 50%), suspicious for malignancy (10 of 38 tumors; 26%), salivary gland neoplasm of uncertain malignant potential (7 of 38 tumors; 18%), and atypia of undetermined significance (2 of 38 tumors; 6%) according to the Milan System for Reporting Salivary Gland Cytopathology. Two malignant cases (2 of 40 tumors; 5%) were metastases. The neoplastic cells were immunoreactive for S100 (23 of 24 tumors), mammaglobin (18 of 18 tumors), GATA‐3 (13 of 13 tumors), AE1/AE3 (7 of 7 tumors), and vimentin (6 of 6 tumors). ETV6‐NTRK3 fusion was detected in 32 of 33 tumors by fluorescence in situ hybridization (n = 32) and next‐generation sequencing (n = 1).

CONCLUSIONS

Familiarity with cytomorphologic features and the immunohistochemical/molecular profile of SC can enhance diagnostic accuracy.;

Secretory carcinoma of the salivary gland, which may manifest with diverse cytomorphology, mammaglobin expression, and ETV6 rearrangement or ETV6‐NTRK3 fusion, was investigated along with cytomorphologic features to facilitate an accurate diagnosis. The results indicated that familiarity with these features and with the immunohistochemical/molecular profile of secretory carcinoma of the salivary gland enhanced diagnostic accuracy.

Overview of the 2022 WHO Classification of Thyroid Neoplasms

This review summarizes the changes in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors that relate to the thyroid gland. The new classification has divided thyroid tumors into several new categories that allow for a clearer understanding of the cell of origin, pathologic features (cytopathology and histopathology), molecular classification, and biological behavior. Follicular cell-derived tumors constitute the majority of thyroid neoplasms. In this new classification, they are divided into benign, low-risk, and malignant neoplasms. Benign tumors include not only follicular adenoma but also variants of adenoma that are of diagnostic and clinical significance, including the ones with papillary architecture, which are often hyperfunctional and oncocytic adenomas. For the first time, there is a detailed account of the multifocal hyperplastic/neoplastic lesions that commonly occur in the clinical setting of multinodular goiter; the term thyroid follicular nodular disease (FND) achieved consensus as the best to describe this enigmatic entity. Low-risk follicular cell-derived neoplasms include non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), thyroid tumors of uncertain malignant potential, and hyalinizing trabecular tumor. Malignant follicular cell-derived neoplasms are stratified based on molecular profiles and aggressiveness. Papillary thyroid carcinomas (PTCs), with many morphological subtypes, represent the BRAF-like malignancies, whereas invasive encapsulated follicular variant PTC and follicular thyroid carcinoma represent the RAS-like malignancies. This new classification requires detailed subtyping of papillary microcarcinomas similar to their counterparts that exceed 1.0 cm and recommends not designating them as a subtype of PTC. The criteria of the tall cell subtype of PTC have been revisited. Cribriform-morular thyroid carcinoma is no longer classified as a subtype of PTC. The term "Hürthle cell" is discouraged, since it is a misnomer. Oncocytic carcinoma is discussed as a distinct entity with the clear recognition that it refers to oncocytic follicular cell-derived neoplasms (composed of > 75% oncocytic cells) that lack characteristic nuclear features of PTC (those would be oncocytic PTCs) and high-grade features (necrosis and ≥ 5 mitoses per 2 mm²). High-grade follicular cell-derived malignancies now include both the traditional poorly differentiated carcinoma as well as high-grade differentiated thyroid carcinomas, since both are characterized by increased mitotic activity and tumor necrosis without anaplastic histology and clinically behave in a similar manner. Anaplastic thyroid carcinoma remains the most undifferentiated form; squamous cell carcinoma of the thyroid is now considered as a subtype of anaplastic carcinoma. Medullary thyroid carcinomas derived from thyroid C cells retain their distinct section, and there is a separate section for mixed tumors composed of both C cells and any follicular cell-derived malignancy. A grading system for medullary thyroid carcinomas is also introduced based on mitotic count, tumor necrosis, and Ki67 labeling index. A number of unusual neoplasms that occur in the thyroid have been placed into new sections based on their cytogenesis. Mucoepidermoid carcinoma and secretory carcinoma of the salivary gland type are now included in one section classified as "salivary gland-type carcinomas of the thyroid." Thymomas, thymic carcinomas and spindle epithelial tumor with thymus-like elements are classified as "thymic tumors within the thyroid." There remain several tumors whose cell lineage is unclear, and they are listed as such; these include sclerosing mucoepidermoid carcinoma with eosinophilia and cribriform-morular thyroid carcinoma. Another important addition is thyroblastoma, an unusual embryonal tumor associated with DICER1 mutations. As in all the WHO books in the 5th edition, mesenchymal and stromal tumors, hematolymphoid neoplasms, germ cell tumors, and metastatic malignancies are discussed separately. The current classification also emphasizes the value of biomarkers that may aid diagnosis and provide prognostic information.

Mutational and immunologic Landscape in malignant Salivary Gland Tumors harbor the potential for novel therapeutic strategies

Salivary gland carcinomas (SGC) are rare (3-6 % of all head and neck cancers) and show biological heterogeneity depending on the respective histological subtype. While complete surgical resection is the standard treatment for localized disease, chemotherapy or radiation therapy are frequently insufficient for the treatment of unresectable or metastasized SGC. Therefore, new therapeutic approaches such as molecularly targeted therapy or the application of immune checkpoint inhibition enhance the treatment repertoire. Accordingly, comprehensive analyses of the genomic landscape and the tumor-microenvironment (TME) are of crucial importance in order to optimize and individualize SGC treatment. This manuscript combines the current scientific knowledge of the composition of the mutational landscape and the TME in SGCs harboring the potential for novel (immune-) targeted therapeutic strategies.

[Salivary gland tumors-an overview : Advances in molecular characterization: Part I]

In den letzten Jahren hat die Charakterisierung der Speicheldrüsenkarzinome einen großen Wandel durchlebt. Morphologisch definierte Entitäten konnten zu einem Großteil auch molekular mit einem oftmals distinkten Genotyp charakterisiert werden. Der erste Teil des Artikels gibt einen Überblick über die Fortschritte der molekularen Charakteristiken des Mukoepidermoidkarzinoms, adenoid-zystischen Karzinoms, Azinuszellkarzinoms, des sekretorischen und intraduktalen Karzinoms sowie des hyalinisierenden klarzelligen Karzinoms. Der molekulare Genotyp kann dabei insbesondere bei der Klassifizierung ungewöhnlicher morphologischer Varianten von großem Nutzen sein. Rekurrente NTRK- oder RET-Genfusionen können dabei nicht nur als diagnostisches Hilfsmittel, sondern auch für eine potenzielle gezielte Therapie genutzt werden.

Diagnosis and treatment of secretory carcinoma arising from the oral minor salivary gland: Two case reports

INTRODUCTION

Secretory carcinoma (SC) is a malignancy of the salivary glands, which is similar to SC of the breast regarding its association with neurotrophic tyrosine receptor kinase fusion-positive gene. SC is a recently described salivary gland tumor, and there are a few reports describing oral minor salivary gland-derived SC. We reported two cases of SC in the oral cavity and reviewed the literature.

PATIENT CONCERNS

The patients included a 65-year-old Japanese woman who presented with a mass of the upper lip and an 84-year-old Japanese man who presented with a mass on the buccal mucosa.

DIAGNOSIS

Diagnosis was based on histomorphological and immunohistochemical findings and identification of a specific translocation of the ETS variant 6-neurotrophic receptor tyrosine kinase 3 gene fusion. Case 1 was finally diagnosed using reverse transcription-polymerase chain reaction with formalin-fixed paraffin-embedded tissue samples, while case 2 was diagnosed using fluorescence in situ hybridization analysis.

INTERVENTIONS AND OUTCOMES

In case 1, excisional biopsy was done and there was no recurrence observed in five-year follow-up. In case 2, tumor resection was done and there was no recurrence observed in two-year follow-up.

CONCLUSION

It is highly likely for many cases of SC to be initially diagnosed as acinic cell carcinoma (AciCC) owing to their similar histological findings. The treatment strategy for minor salivary gland-originated SC is similar to that of AciCC; however, SC is often highly malignant and involves a high risk of cervical lymph node metastasis. Thus, establishing an accurate diagnosis together with pathologists and confirming the presence of the ETS variant 6-neurotrophic receptor tyrosine kinase 3 fusion gene using genetic analysis is important.

Fusion-Positive Salivary Gland Carcinomas

Salivary gland tumors are a rare, heterogeneous group of neoplasms that pose significant diagnostic challenges for the histopathologist. Histopathological diagnosis relies primarily on morphological assessment, with ancillary special stains and immunohistochemistry. In recent years, new defining genomic alterations have been characterized in these tumors. In particular, they include gene fusions which have shown to be tightly tumor-type specific, and thus valuable for use in diagnostically challenging cases. These discoveries also help in refining tumor classification. Furthermore, such genetic alterations may have prognostic as well as potentially therapeutic implications in the era of personalized medicine. This review aims at providing a summary of the most recent updates in this field.

Pan-TRK Immunohistochemistry Is Highly Correlated With NTRK3 Gene Rearrangements in Salivary Gland Tumors

AIMS

Secretory carcinoma (SC) is characterized by ETV6 rearrangements, most often ETV6-NTRK3 fusion. Given its histologic overlap with other salivary gland tumors (SGTs), SCs can be difficult to diagnose without genetic confirmation. A recently developed pan-TRK (tropomyosin receptor kinase) antibody shows promise for identifying tumors with NTRK (neurotrophic tyrosine kinase receptor 3) fusions. The aim of this study was to evaluate the utility of pan-TRK immunohistochemistry in distinguishing SCs from mimics and selecting patients eligible for TRK inhibitor clinical trials. We examined whole-tissue sections from 111 SGTs with molecular characterization, including 26 SCs (23 with ETV6-NTRK3 fusion and 3 with ETV6-RET fusion detected by ligation-dependent reverse transcription-polymerase chain reaction, next-generation sequencing and 85 non-SC SGTs (no ETV6-NTRK3 fusion). Immunohistochemistry was performed with a pan-TRK rabbit monoclonal antibody. When any pan-TRK staining (nuclear or cytoplasmic with any staining intensity) was considered to indicate positivity, 22 of 23 SCs with ETV6-NTRK3 fusion (95.7%) and 33 of 85 non-SC (38.8%) salivary neoplasms were positive, mainly basal cell adenoma, pleomorphic adenomas, adenoid cystic carcinomas, and epithelial-myoepithelial carcinomas. All SCs with ETV6-RET fusion were entirely negative. When only nuclear pan-TRK staining with any staining intensity was considered positive, 18 of 23 SCs with ETV6-NTRK3 fusion (78.3%) were positive, 11 among them with diffuse staining (>30% of cells). All non-SCs and SCs with ETV6-RET fusion were entirely negative. In comparison to molecular analysis (ligation-dependent reverse transcription-polymerase chain reaction, next-generation sequencing), nuclear pan-TRK IHC has a sensitivity of 78.3% and a specificity of 100% for diagnosing SCs with ETV6-NTRK3 fusion, 69% and 100% for SCs (all fusions). Pan-TRK is a reasonable screening test for diagnosing SCs among SGTs when taking only nuclear staining into account. Although pan-TRK expression is not entirely sensitive for SCs, nuclear staining is highly specific for SCs with ETV6-NTRK3 fusion. The lack of pan-TRK immunoreactivity in a subset of SCs is suggestive of atypical exons 4 to 14 or exons 5 to 14 ETV6-NTRK3 fusion or non-NTRK alternative fusion partners such as ETV6-RET. Pan-TRK staining can serve as a strong diagnostic marker to distinguish SC from it mimics and to select patients eligible for TRK inhibitor clinical trials.

Undifferentiated and dedifferentiated head and neck carcinomas

Undifferentiated carcinomas arising at salivary gland and head and neck mucosal sites may originate either de novo or through a process of dedifferentiation of a differentiated carcinoma. While in the latter group the diagnosis is largely dependent on the identification of the differentiated component or recognition of a specific genotype, the classification of undifferentiated carcinomas that lack a differentiated component is mainly based on the identification of specific genetic drivers, like for example the NUTM1 fusions in NUT carcinoma. A further category is represented by virus associated carcinomas (mainly HPV and EBV), that frequently displays an undifferentiated morphology. Overall, these tumors often represent a diagnostic challenge, especially in small biopsies. This review summarizes and discuss the diagnostic approach to the main head and neck carcinoma types that frequently or occasionally display an undifferentiated appearance, with a focus on salivary gland, oropharyngeal, nasopharyngeal and sinonasal subsites.

Clinicopathologic and Molecular Characterization of Four Cases of Pediatric Salivary Secretory Carcinoma (SSC), One with ETV6-RET Fusion

Salivary gland secretory carcinoma (SSC) is a neoplasm with characteristic histologic features, similar to those of secretory carcinoma of the breast. Only a few pediatric SSC cases have been reported, all with ETV6-NTRK3 fusion. We present four new pediatric SSC examples, one with a novel ETV6-RET fusion. Four cases of SSC were diagnosed between 2010 and 2020: 2 boys, 7 and 9 year-old with parotid tumors (1.5 and 1.3 cm, respectively); and two 14 year-old girls: one with a submandibular tumor (2.1 cm), and one with a parotid lesion (1.2 cm). Histologically, all tumors were similar: well-circumscribed lesions composed by mid-size, monotonous cells with eosinophilic and sometimes vacuolated cytoplasm. The nuclei are oval to round with open chromatin and a single nucleolus. There are duct-like structures and microcysts with colloid-like material. Immunohistochemically, tumor cells are positive for S100, CK7, mammaglobin and GATA3. A classic ETV6-NTRK3 translocation was confirmed in the three parotid tumors; an ETV6-RET fusion was demonstrated in the submandibular lesion. All patients underwent complete surgical resection and are alive without tumor recurrence after a follow-up time ranging from one to 4 years. Pediatric SSC is extremely rare but their characteristic morphology and immunohphenotype facilitate their diagnosis. We describe the first pediatric case with the recently reported ETV6-RET fusion. Similar to adult cases, this tumor is morphologically undistinguishable from those carrying the classic ETV6-NTRK3 translocation. Thus, in pediatric cases with morphology suggestive of SSC and negative ETV6-NTRK3 by RT-PCR, other possible fusions should be investigated.

A case of "ETV6-FISH-negative" secretory carcinoma of the parotid gland: immunohistochemical study

Secretory carcinoma of the salivary glands is a relatively new disease concept, and is characterized by "morphological resemblance to mammary secretory carcinoma and ETV6-NTRK3 gene fusion." Herein we describe a confusing case and briefly discuss practical diagnostic problems. The patient was a 71-year-old Japanese man who had a tumor consistent with secretory carcinoma at the microscopic and immunohistochemical levels. Immunohistochemically, EMA and S100 protein were noted to be positive along with various cytokeratins as well as mammaglobin and pSTAT5. Moreover, vimentin was focally positive. Smooth muscle actin, p63, p40, and androgen receptor were negative. However, a search using fluorescence in situ hybridization did not reveal a definite split signal for the ETV6 gene. It is presumed that confirming the diagnosis of secretory carcinoma without genetic retrieval will be accepted as a diagnostic method, and we hope that worldwide general recognition may earlier reach "gradual acceptance."

Intraductal carcinoma of the salivary gland with NCOA4-RET: expanding the morphologic spectrum and an algorithmic diagnostic approach

After the publication of the 2017 World Health Organization Classification of Head and Neck Tumours, there has been increasing interest in the classification of newly categorized intraductal carcinomas. Intraductal carcinoma (IC) is an indolent tumor, typically arising in the parotid gland, with an intact myoepithelial layer and a cystic, papillary, often cribriform architecture. Early studies of IC identified a heterogeneous group of molecular alterations driving neoplasia, and recent studies have defined three primary morphological/immunohistochemical variants, subsequently linking these morphologic variants with defined molecular signatures. Although studies to date have pointed toward distinct molecular alterations after histological classification, this study used a novel approach, focusing primarily on six cases of IC with NCOA4-RET gene rearrangement as determined by next-generation sequencing and describing the spectrum of clinicopathologic findings within that molecularly-defined group, among them a unique association between the NCOA4-RET fusion and hybrid variant IC and the first case of IC arising in association with a pleomorphic adenoma. RET-rearranged IC show histological and immunohistochemical overlap with the more widely recognized secretory carcinoma, including low-grade morphology, a lumen-forming or microcystic growth pattern, and co-expression of S100, SOX10, and mammaglobin, findings undoubtedly leading to misdiagnosis. Typically regarded to have ETV6-NTRK3 fusions, secretory carcinomas may alternatively arise with RET fusions as well. Adding our cohort of six NCOA4-RET fusion-positive IC compared with four cases of secretory carcinoma with ETV6-RET fusions and a single case of fusion-negative IC with salivary duct carcinoma-like genetics, we propose a diagnostic algorithm that integrates histological elements, including atypia and invasiveness, and the likelihood of specific molecular alterations to increase diagnostic accuracy in what can be a very subtle diagnosis with important clinical implications.

Diagnostic challenges and successful organ-preserving therapy in a case of secretory carcinoma of minor salivary glands

BACKGROUND

Secretory carcinoma is a more recently described subtype of salivary gland carcinoma that may pose diagnostic challenges and frequently harbors NTRK fusions that may successfully be targeted by TRK inhibitors in advanced disease.

CASE

We present the case of a female patient with secretory carcinoma arising in the base of tongue with persistent disease after debulking surgery and definitive chemoradiation. As an alternative to salvage surgery, which would have resulted in significant impairment of swallowing and speech function, a targeted therapy with the TRK-inhibitor larotrectinib against an identified ETV6-NTRK3 fusion product was initiated. Larotrectinib treatment has been well tolerated, resulted in durable complete response and the patient maintains good swallowing and speech function.

CONCLUSION

The presented case underscores the importance of the accurate diagnosis of secretory carcinoma. It further highlights the impact of molecular testing as targeted therapies may play an important role in the management of advanced salivary gland cancers.

Differential diagnosis and treatment of salivary secretory carcinoma and acinic cell carcinoma

Secretory carcinoma (SC) and acinic cell carcinoma (AciCC) are two rare tumors originating in the salivary gland of the head and neck. Before the World Health Organization (WHO) classified SC as a new entity in 2017, the majority of SC cases were incorrectly diagnosed as AciCC. Indeed, they are similar in biological behaviors, clinical manifestations and histomorphological features. Especially, SC and zymogen granule-poor AciCC are difficult to differentiate, which brings a tough challenge in clinical diagnosis. This article provides an updated understanding of the differential diagnosis in SC and AciCC from two main perspectives: histopathology and molecular genetics. The targeted therapies for both tumors are also mentioned. It aims to give some hints in clinical diagnosis and treatment, in hopes that patients with adequate diagnosis could obtain the opportunityformore effective treatment.

High-grade Transformation/Dedifferentiation in Salivary Gland Carcinomas: Occurrence Across Subtypes and Clinical Significance

High-grade transformation (HGT) or dedifferentiation has been described in a variety of salivary gland carcinomas, including acinic cell carcinoma, secretory carcinoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, polymorphous adenocarcinoma, low-grade mucoepidermoid carcinoma, and hyalinizing clear cell carcinoma. High-grade (HG) transformed tumors are composed of a conventional low-grade component characterized by specific microscopic and immunohistochemical features for the given entity, intermingled with or juxtaposed to areas of HG morphology. This is usually either poorly differentiated adenocarcinoma, carcinoma not otherwise specified, or undifferentiated carcinoma, in which the original line of differentiation is lost. The HG component is composed of solid nests of anaplastic cells with large vesicular pleomorphic nuclei, prominent nucleoli, and abundant cytoplasm. Frequent mitoses and extensive necrosis may be present. The Ki-67 labeling index is consistently higher in the HG component. The molecular genetic mechanisms responsible for HGT of salivary gland carcinomas are largely unknown, though p53 inactivation and human epidermal growth factor receptor 2 overexpression and/or gene amplification have been demonstrated in the HG component in a few examples, the frequency varies for each histologic type. Salivary gland carcinomas with HGT are more aggressive than conventional carcinomas, with a higher local recurrence rate and a poorer prognosis. They have a high propensity for cervical lymph node metastasis suggesting a need for a wider resection and neck dissection. HGT of salivary gland carcinoma can occur either at initial presentation or less commonly at the time of recurrence, sometimes following postoperative radiotherapy. The potential for HGT in almost any type of salivary gland carcinoma warrants a thorough sampling of all salivary gland malignancies to prevent oversight of a HG component.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

SalvGlandDx - a comprehensive salivary gland neoplasm specific next generation sequencing panel to facilitate diagnosis and identify therapeutic targets

Diagnosis of salivary gland neoplasms is often challenging due to their high morphological diversity and overlaps. Several recurrent molecular alterations have been described recently, which can serve as powerful diagnostic tools and potential therapeutic targets (e.g. NTRK or RET fusions). However, current sequential molecular testing can be expensive and time consuming. In order to facilitate the diagnosis of salivary gland neoplasms, we designed an all-in-one RNA-based next generation sequencing panel suitable for the detection of mutations, fusions and gene expression levels (including NR4A3) of 27 genes involved in salivary gland neoplasms. Here we present the validation of the "SalvGlandDx" panel on FFPE histological specimen including fine needle aspiration (FNA) cell block material, against the standard methods currently used at our institution. In a second part we describe selected unique cases in which the SalvGlandDx panel allowed proper diagnosis and new insights into special molecular characteristics of selected salivary gland tumors. We characterize a unique salivary gland adenocarcinoma harboring a ZCCHC7-NTRK2 fusion, a highly uncommon spindle cell and pseudoangiomatoid adenoid-cystic carcinoma with MYBL1-NFIB fusion, and a purely oncocytic mucoepidermoid carcinoma, whereas diagnosis could be made by detection of a CRTC3-MAML2 rearrangement on the cell block specimen of the FNA. Further, a rare case of a SS18-ZBTB7A rearranged low-grade adenocarcinoma previously described as potential spectrum of microsecretory adenocarcinoma, is reported. In addition, features of six cases within the spectrum of polymorphous adenocarcinoma / cribriform adenocarcinoma of salivary gland including PRKD1 p.E710D mutations and novel fusions involving PRKAR2A-PRKD1, SNX9-PRKD1 and ATL2-PRKD3, are described.

Oncocytic intraductal carcinoma of salivary glands: a distinct variant with TRIM33-RET fusions and BRAF V600E mutations

AIMS

Salivary gland intraductal carcinoma (IDC) is a complex ductal neoplasm surrounded by a layer of myoepithelial cells. Recent insights have shown that there are three different types: intercalated duct-like, with frequent NCOA4-RET fusions; apocrine, with salivary duct carcinoma-like mutations; and mixed intercalated duct-like/apocrine, with RET fusions, including TRIM27-RET. In addition, an oncocytic IDC has been described, but it remains unclear whether it represents a fourth variant or simply oncocytic metaplasia of another IDC type. Our aim was to more completely characterize oncocytic IDC.

METHODS AND RESULTS

Six IDCs with oncocytic changes were retrieved from the authors' archives, from three men and three women ranging in age from 45 to 75 years (mean, 63 years). Five arose in the parotid gland, with one in an accessory parotid gland. Four patients with follow-up were free of disease after 1-23 months. Several immunostains (S100, mammaglobin, androgen receptor, and p63/p40) and molecular tools (RNA sequencing, RET fluorescence in-situ hybridisation, BRAF V600E VE1 immunohistochemistry, and Sanger sequencing) were applied. Histologically, the tumours were variably cystic with solid intracystic nodules often difficult to recognise as intraductal. In all, tumour ducts were positive for S100 and mammaglobin, negative for androgen receptor, and completely surrounded by myoepithelial cells positive for p63/p40. Molecular analysis revealed TRIM33-RET in two of six cases, NCOA4-RET in one of six cases, and BRAF V600E in two of six cases. One case had no identifiable alterations.

CONCLUSIONS

Oncocytic IDC shares similarities with intercalated duct-like IDC. Although additional verification is needed, the oncocytic variant appears to be sufficiently unique to be now regarded as the fourth distinct subtype of IDC. Because of its indolent nature, oncocytic IDC should be distinguished from histological mimics.

ALK Rearrangements Characterize 2 Distinct Types of Salivary Gland Carcinomas: Clinicopathologic and Molecular Analysis of 4 Cases and Literature Review

The majority of salivary gland carcinomas are characterized by recurrent gene fusions that proved highly valuable diagnostically, but only rarely of therapeutic impact. Most of these fusion-positive carcinomas belong to the low-grade or intermediate-grade biological category. To date, only 5 cases of salivary gland carcinomas carrying an oncogenic ALK fusion have been reported in 4 recent studies, but their phenotypic spectrum and their nosological classification remain uncharacterized. We herein describe in detail the clinicopathologic and molecular features of 4 ALK-fusion-positive salivary carcinomas and review previously reported cases to assess if they could be classified into a defined World Health Organization (WHO) category. Patients were 3 men and 1 woman aged from 67 to 79 years (median: 70 y). All tumors originated in the parotid gland. Their size ranged from 1.1 to 3 cm (mean, 2 cm). Three tumors were de novo high-grade salivary duct carcinomas (SDCs) and 1 was a low-grade intercalated-type intraductal carcinoma. Histologically, high-grade tumors were predominantly solid, composed of intimately admixed basal (CK5+, androgen-) and luminal (CK5-, androgen+) components. The remarkable basal component showed squamoid basophilic pattern imparting an adenosquamous-like appearance in all cases. Conventional apocrine intraductal high-grade carcinoma was noted in 1 case. Prominent intraductal growth of the solid basal component (highlighted by p63 staining) was seen in all cases. The tumor cells expressed CK7 (3/3), mammaglobin (3/3, 1 focal), GATA3 (3/3, 1 focal), variably CK5 (3/3), and focally the androgen receptor (1/3), but lacked expression of HER2/neu, SOX10, MUC4, TTF1, S100, and Napsin A. The low-grade tumor showed classic histologic and immunophenotypic features of intercalated-type noninvasive intraductal carcinoma. Molecular profiling showed rearrangements involving exon 20 of ALK in all cases, confirmed by ALK immunohistochemistry (IHC and FISH). The fusion partner was EML4 (n=2) and STRN (n=1) in high-grade tumors and EML4 in the intraductal carcinoma. Two patients with high-grade tumors developed progressive disease (1 died at 9 mo; 1 alive under palliative therapy at 5 mo). This series and a review of 5 published cases indicate that ALK rearrangements characterize 2 distinct subsets of salivary gland carcinomas in the spectrum of high-grade androgen-poor, basal-like SDC (total reported: 5 cases) and low-grade intercalated-type intraductal carcinomas (4 cases). Given the therapeutic relevance of ALK fusions, inclusion of ALK IHC in any atypical-looking or androgen-poor SDC and in high-grade adenocarcinoma-not otherwise specified is recommended. Absence of aberrant ALK expression in genetically characterized secretory (n=15) and intraductal (n=9) carcinomas lacking ALK fusions underlines the value of ALK IHC as a diagnostic screening method for identifying potential cases.

Secretory Carcinoma of the Oral Cavity: A Retrospective Case Series with Review of Literature

Secretory carcinoma (SC) is an uncommon salivary gland neoplasm of the oral cavity that microscopically may mimic acinic cell carcinoma (ACC) and mucoepidermoid carcinoma (MEC). This study describes a series of SC in minor glands with a literature review. We performed a retrospective search for oral SC, within the archives of the University of Florida, Oral Pathology and Surgical Pathology Biopsy services from 2010 to 2018. A total of 10 SCs were identified in the oral and maxillofacial region, four of which were in the minor salivary glands. The demographic, clinical, histological, and molecular findings were aggregated for all 4 cases. Patient age varied from 30 to 60 years, with an average of 45 years. Two cases each were in female and male patients. Two cases presented on the labial mucosa, and one each on the hard and soft palate. Immunohistochemical (IHC) staining showed mammaglobin positivity in all cases, GATA3 positivity in two cases, S100 positivity in three cases, and SOX10 positivity in only one case. Fluorescence in situ hybridization demonstrated positivity for ETV6-NTRK3 fusion in 4 cases. Although oral SC is rare, pathologists should be aware of the histologic overlap between the SC and other salivary gland neoplasms such as ACC and MEC. A judicious application of IHC staining would aid in diagnosis. SC should be considered in the differential diagnosis for intraoral salivary gland tumors.

Secretory carcinoma of salivary glands at the National Cancer Institute: A 20-year retrospective clinical, pathological, immunohistochemical and molecular study

OBJECTIVES

This study aim was to review cases of acinic cell carcinoma (the main differential diagnosis of secretory carcinoma) that were diagnosed and treated at the National Cancer Institute of Brazil (INCA) between 1996 and 2016. The primary objective was to identify underdiagnosed cases of secretory carcinoma via a clinical, immunopathological and molecular reassessment.

MATERIALS AND METHODS

This is a cross sectional study, with retrospective data collection from medical records and histological specimen review, with staining for periodic acid-Schiff (PAS) and PAS with diastase, immunohistochemistry for S-100, mammaglobin, and DOG-1, and droplet digital RT-PCR for ETV6-NTRK3. The Research Ethics Committee approved this study, and the patients allowed their participation through informed consent.

RESULTS

Eighty-three cases of acinic cell carcinoma were diagnosed and treated in the specified period at INCA, of which, seven had their diagnosis changed to secretory carcinoma.

CONCLUSION

The present study adds seven cases of secretory carcinoma to the literature, contributing to a better understanding of the epidemiological, histological, immunohistochemical and molecular characteristics of this recently described tumor. Also, the use of a comprehensive diagnostic approach, including immunohistochemical and molecular methods, along with classical morphological studies, allowed the reclassification of acinic cell carcinoma to secretory carcinoma.