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

Parotid Gland Tumors: Molecular Diagnostic Approaches

Parotid gland pathology represents a web of differential diagnoses. There are many complex cases that require extensive diagnostic tests for a complete and correct final pathology diagnosis. Currently the official classification of parotid gland tumors extends over more than 40 subtypes. We performed a query of the PubMed database regarding the use of molecular biology tests in performing a better characterization of the tumors in specific cases. By using fluorescence in situ hybridization (FISH), reverse transcription polymerase chain reaction (RT-PCR) or next-generation sequencing, the team managing complex cases can offer a personalized therapeutic solution. We review the molecular differential diagnosis according to published articles in the last 5 years for many types of parotid gland tumors ranging from benign to borderline malign tumors to malign aggressive tumors. Mucoepidermoid carcinoma is a distinct subtype of parotid malignancy that was the subject of a consistent number of articles. However, the molecular biology diagnosis techniques helped more in excluding the diagnosis of mucoepidermoid carcinoma, and probably retrospectively limiting the number of cases with this final diagnosis. In Romania, the molecular biology diagnosis is available only in limited research facilities and should receive more consistent funding that will make it available on a larger scale. The novelty of this scoping review is that we propose an algorithm for molecular differential diagnosis of the tumors that could be encountered in the parotid gland.

A tale of recurrent secretory carcinoma of submandibular gland in an adolescent male: A rare presentation of a rare tumor

Mammary analogue secretory carcinoma (MASC) is a rare salivary gland tumor which shares its histologic, immunohistochemical, and genetic features with the secretory carcinoma (SC) of breast. In this case report, we describe a case of MASC in a young adolescent male with swelling in the right angle of mandible which is a relatively rare site to present along with its correlation of cytological, histological, and immunohistochemical features. A 16-year-old male came with the complaint of swelling in the right angle of mandible since 2 years. Contrast-enhanced computed tomography (CECT) neck revealed differential diagnosis of nerve sheath tumor, pleomorphic adenoma, and adenoid cystic neoplasm was kept, and subsequently fine-needle aspiration cytology (FNAC) was done. FNAC was done in which differential diagnosis of myoepithelial neoplasm, acinic cell carcinoma, and SC was given. Surgical excision was done followed by histopathological examination. Immunohistochemistry panel was also applied, and final diagnosis of SC was rendered. SC has distinct cytological, histological, and immunohistochemical features which should be recognized by the pathologists for the appropriate management of the patient.

Diagnostic utility and sensitivities of matrix Gla protein (MGP), TRPS1 and GATA3 in breast cancer: focusing on metastatic breast cancer, invasive breast carcinoma with special features, and salivary gland-type tumours

Matrix Gla protein (MGP) and trichorhinophalangeal syndrome type 1 (TRPS1) have recently emerged as novel breast-specific immunohistochemical (IHC) markers, particularly for triple-negative breast cancer (TNBC) and metaplastic carcinoma. The present study aimed to validate and compare the expression of MGP, TRPS1 and GATA binding protein 3 (GATA3) in metastatic breast carcinoma (MBC), invasive breast carcinoma (IBC) with special features, including special types of invasive breast carcinoma (IBC-STs) and invasive breast carcinoma of no special type with unique features, and mammary and non-mammary salivary gland-type tumours (SGTs). Among all enrolled cases, MGP, TRPS1 and GATA3 had comparable high positivity for ER/PR-positive (p=0.148) and HER2-positive (p=0.310) breast carcinoma (BC), while GATA3 positivity was significantly lower in TNBC (p<0.001). Similarly, the positive rates of MGP and TRPS1 in MBCs (99.4%), were higher than in GATA3 (90.9%, p<0.001). Among the IBC-STs, 98.4% of invasive lobular carcinomas (ILCs) were positive for all three markers. Among neuroendocrine tumours (NTs), all cases were positive for TRPS1 and GATA3, while MGP positivity was relatively low (81.8%, p=0.313). In the neuroendocrine carcinoma (NC) subgroup, all cases were positive for GATA3 and MGP, while one case was negative for TRPS1. All carcinomas with apocrine differentiation (APOs) were positive for GATA3 and MGP, while only 60% of the cases demonstrated moderate staining for TRPS1. Among mammary SGTs, MGP demonstrated the highest positivity (100%), followed by TRPS1 (96.0%) and GATA3 (72.0%). Positive staining for these markers was also frequently observed in non-mammary SGTs. Our findings further validate the high sensitivity of MGP and TRPS1 in MBCs, IBC-STs, and breast SGTs. However, none of these markers are capable of distinguishing between mammary and non-mammary SGTs.

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.

Salivary Gland Secretory Carcinoma; Review of 13 Years World-Wide Experience and Meta-Analysis

OBJECTIVES

Secretory Carcinoma is a malignant salivary gland tumor, initially described in 2010. This rare tumor is associated with the translocation t(12;15) (p13;q25), resulting in the fusion gene ETV6-NTRK3. Since this tumor is quite rare, most publications describe only small cohorts of patients. We aimed to investigate the clinical, pathological, and prognostic features of this newly defined malignant entity.

DATA SOURCES

Pubmed, Google Scholar, and Web of Science databases.

REVIEW METHODS

All published articles between 2010 and 2023 were reviewed. Search terms included the terms "Mammary Analogue Secretory Carcinoma" and "Secretory Carcinoma". All articles published in English reporting on Secretory Carcinoma of salivary glands were retrieved.

RESULTS

One-hundred and 12 retrospective articles reporting a total of 674 patients were included, with 52% males and a mean age of 44.9 ± 18.9. The event rate for patients with advanced-stage disease (Stage 3/4) at presentation was 24.1% (95% CI 17.6%-31.9%, I2  = 9.2%), 14.6% for regional metastases (95% CI 10.5%-20%, I2  = 12%), and the event rate of distant metastasis was 8.4% (95% CI 5.5%-12.7%, I2  = 4.2%). Adjuvant radiotherapy was administered for 30.3% of patients (95% CI 24.1%-37.2%, I2  = 21.5%). The recurrence rate was 19% (95% CI 15.1%-23.8%, I2  = 5%). Survival outcomes showed a 17.2% death of disease rate for Secretory Carcinoma patients (95% CI 13.5%-21.8%, I2  = 7.3%).

CONCLUSIONS

Secretory Carcinoma is a rare and relatively newly defined entity arising in the parotid gland most commonly. Characterized as a low-grade tumor, the majority of patients are diagnosed at an early stage, without regional or distant disease, and the prognosis is relatively good.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1716-1724, 2024.

Diagnostic Utility of Expression Pattern of S100/Mammaglobin/SOX10/DOG 1 Immunohistochemistry in Differentiation of Secretory and Acinic Cell Carcinoma: A Systematic Review and Meta-Analysis

Secretory carcinoma (SC) is a relatively new disease entity, separate from acinic cell carcinoma (AciCC), which frequently displays ETV6-NTRK3 gene fusion. However, the differences between SC and AciCC remain ambiguous. Genetic diversity makes its diagnosis complicated. In this regard combined expression of immunohistochemistry markers S100/Mammaglobin/SOX10 and DOG1 is need of the hour as alternative methodology. The current systematic review was to investigate the diagnostic utility of combined immunohistochemical expression of S100/Mammaglobin/SOX10/DOG1 in distinction of SC from AciCC histologically. An electronic search of databases was carried out using MEDLINE by PubMed, Google scholar, Scopus and Web of science. Articles inclusive of SC and AciCC were assessed with S100/Mammaglobin/SOX10/DOG1 immunohistochemistry and their predominant expression pattern, predictive values, sensitivity and specificity were gathered. Fourteen eligible articles were analysed, which revealed predominant immunostaining pattern of S100 + /Mammaglobin + /SOX10 + /DOG1- by nearly all ETV6::NTRK3 fusion prevalent SCs alongside with other gene fusions like RET, MET and MAML3 with 98.4% sensitivity as well as 86.1% specificity. The evidence supports that S100/Mammaglobin/SOX10/DOG1 combined immunostaining can serve as a reliable diagnostic method to differentiate secretory from acinic cell carcinoma.

The genetic and immune features of salivary gland secretory carcinoma with high-grade transformation

OBJECTIVES

To compare the clinicopathological, molecular, and immune features of conventional and high-grade transformation (HGT) secretory carcinoma (SC) in salivary glands.

MATERIALS AND METHODS

The clinicopathological data of 88 cases including 74 conventional SCs and 14 SCs with HGT were reviewed. Targeted next-generation sequencing was performed in 11 SCs with HGT and 7 conventional SCs. The level of PD-L1 and CD8+ TILs was determined by immunohistochemistry.

RESULTS

Compared with the conventional group, the rates of nodal metastasis, local recurrence, distant metastasis and mortality were significantly higher in the HGT cohort. Mutations of ARID1A/B, KMT2A, HOXD13, NRG1 and ETV6 genes were identified in HGT SCs. A recurrent E307G mutation in GATA6 gene was also observed in two cases. Two deceased HGT patients with distant metastasis harboured NOTCH3 mutations. ETV6-RET translocation was prone to occur in the HGT SCs. Additionally, PD-L1 expression was low, and CD8+ TILs were sparse in most HGT cases.

CONCLUSION

Our findings reveal novel gene alterations involved in the progression of HGT in SCs. Most HGT SCs patients cannot benefit from PD-L1 blocking and may be approached with a distinct treatment strategy including the lymph node dissection and application of molecular target drugs in precision oncology.

Efficacy of Fine-Needle Aspiration Cytology in Diagnosing Secretory Carcinoma of Salivary Gland: A Systematic Review and Meta-Analysis

INTRODUCTION

The diagnosis of salivary gland secretory carcinoma (SC) in fine-needle aspiration specimens is challenging because its low-grade nature makes it difficult to differentiate it from various benign or malignant salivary gland neoplasms. Currently, the gold standard is demonstration of ETV6-NTRK3 fusion gene. However, the decision for ordering this costly molecular testing can be facilitated by the correct recognition of its cytomorphological features. The aim of the review was to determine the accuracy of fine-needle aspiration cytology (FNAC) in diagnosis of salivary gland SC. The secondary objective was to recognize varied cytomorphological patterns, characteristic features of SC and differentiate it from other neoplasms.

METHODS

PubMed/MEDLINE, Science Direct, Embase, Cochrane review, and PROSPERO databases were searched for studies having the following key search terms: ("secretory carcinoma of salivary gland" OR "mammary analogue secretory carcinoma of salivary gland") AND ("Cytology" OR "Cytological features" OR "aspirate" OR "cytodiagnosis") published in the time frame of 2010 to June 2023. Studies reporting cytological features of the salivary gland tumors which were confirmed/diagnosed as SC on molecular investigation, were included in the systematic review. Finally, seventeen studies reporting a total of 45 cases were included in the metanalysis.

RESULTS

The sensitivity of the FNAC in diagnosing SC in salivary gland is 27.7% (95% CI: 16.6-42.5%). The LR+ (positive likelihood ratio) was 0.654 (0.344-1.245), LR- (negative likelihood ratio) was 1.023 (0.538-1.946), and diagnostic odds ratio was 0.421 (0.129-1.374). The molecular testing and/or immunohistochemistry performed on cell block increased the diagnostic accuracy.

CONCLUSION

Recognition of subtle cytomorphological patterns, i.e., papillary formation, clusters, and singly dispersed cells along with presence of fine intracytoplasmic vacuolations were the characteristic findings in majority of cases, confirmed with diagnostic molecular profiling. This may be helpful in identification of this rare entity with limited published literature and help in increasing diagnostic accuracy.

Secretory carcinoma of salivary gland: A rare tumor masquerading as acinic cell carcinoma on cytology

Secretory carcinoma (SC) was originally described as mammary analogue secretory carcinoma (MASC). We present here a case of 33 years old male who came to ENT outpatient department with a complaint of swelling over the left side of his neck for 8 months. On Fine-needle aspiration cytology, an impression of cytomorphological features suggestive of acinic cell carcinoma (Milan category V) was given. Left functional endoscopic sinus surgery was done. On histopathology, a final impression of Secretory carcinoma, the left submandibular gland was given with pathological stage classification as pT2N0Mx. SC of the salivary gland is a rare entity that may pose diagnostic challenges. Awareness of its cytologic features is paramount to achieve an accurate diagnosis. Morphologic interpretation must be supported by an immunohistochemical profile and molecular studies to confirm a diagnosis of SC.

Cytopathology of benign sebaceous salivary gland neoplasia: Comparison of two analogous yet dissimilar entities

INTRODUCTION

Benign sebaceous salivary gland (SG) neoplasms represent approximately 0.2% of all salivary gland neoplasms. Not only are fine needle aspiration (FNA) biopsy findings of sebaceous adenoma (SA) and sebaceous lymphadenoma (SLA) limited, but their findings are also rarely compared with one another.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of benign sebaceous SG neoplasms with concomitant histopathological verification. FNA biopsy and cell collection were performed using standard technique.

RESULTS

One case each of parotid SA and parotid SLA showed markedly dissimilar cytomorphology. The SA case was composed of a repetitive population of profusely multivacuolated polygonal cells with single and multiple nuclei, and was specifically recognised cytologically as a sebaceous neoplasm due to its characteristic cytoplasmic vacuolisation. The SLA case, however, was characterised by smears filled primarily with lymphocytes and only scant widely scattered basaloid cell clusters. A non-specific diagnosis of basaloid neoplasm was rendered. In retrospect, recognition of sebaceous differentiation was limited to rare cell groups.

CONCLUSION

Though nominally, epidemiologically, and to a degree histopathologically analogous, the cytopathology of SA and SLA are markedly dissimilar, reflecting the dominant cell component in each. With FNA biopsy, a specific interpretation is more likely for SA than SLA due to the overwhelming obscuring lymphoid population in the latter.

Secretory carcinoma of major and minor salivary glands with ETV6-NTRK3 gene fusion: overcoming misdiagnosis in the era of tumour-agnostic therapy with TRK inhibitors

Introduction

Secretory carcinoma (SC) of the salivary gland is an extraordinarily rare tumour. Accurate diagnosis of SC is crucial for understanding the clinical course, prognosis, and selection of optimal therapy. The aim of this research was to analyse retrospectively the clinical and pathological characteristics of patients diagnosed with SC of the salivary gland from 2017 onwards, which aligns with its addition to the World Health Organization classification.

Material and methods

We conducted a retrospective, single-centre, clinicopathological analysis of patients diagnosed with SC of the salivary gland between 2017 and 2022. The analysis included the evaluation of NTRK3 gene rearrangements and immunohistochemical (IHC) profiling.

Results

The study included 6 patients, comprising 4 women and 2 men. The average age of the patients was 50 years (standard deviation 26). Three cases presented with tumours in the parotid gland, while one case each involved the submandibular gland, sinonasal tract, and buccal mucosa. Interestingly, despite the characteristic IHC profile, each case was initially diagnosed as a different type of salivary gland cancer. Next-generation sequencing analysis was performed in 3 cases, revealing the presence of the ETV6-NTRK3 fusion gene. This cohort notably features an intriguing case: the youngest patient documented in literature, distinguished by extended follow-up and delayed recurrence.

Conclusions

In summary, emphasizing the risk of misdiagnosis is pivotal in the context of SC of the salivary gland, which can manifest across diverse glandular sites. Accurate diagnosis, underscored by the assessment of NTRK3 gene rearrangements, assumes a critical role in guiding effective management and treatment decisions.

Secretory carcinoma in the parotid gland of a pediatric patient. A challenging diagnosis

Secretory carcinoma is a rare, recently identified and recognized neoplasm in major salivary glands. Few cases have been described with only 16 pediatric cases in the literature. We present a case preoperatively identified as a benign parotid lesion whose management was delayed due to the COVID-19 pandemic. Post enucleation of the lesion, histology identified a secretory carcinoma. This led to further and more extensive surgery to ensure complete removal. Clinicians and histopathologists should be aware of secretory carcinoma in their differential, as a high index of suspicion is required to ensure appropriate investigations are performed to obtain the diagnosis. Early identification is important to allow timely appropriate surgery to be performed.

WT1 as a myoepithelial marker: a comparative study of breast, cutaneous, and salivary gland lesions

WT1 immunostain is expressed in various benign and malignant neoplasms, as well as normal myoepithelial cells. WT1 shows differential expression in non-neoplastic, benign, and malignant neoplastic myoepithelial cells of the salivary gland. In this study, WT1 immunostain and other myoepithelial markers were compared to investigate the value of WT1 as a myoepithelial marker, and to delineate the expression profile of WT1 in nonsalivary gland myoepithelial cells. WT1, p63, and calponin immunostains were performed on normal and lesional tissues from the breast (adenosis, sclerosing adenosis, lactating adenoma, nipple adenoma, tubular adenoma, adenomyoepithelioma, and adenoid cystic carcinoma [ACC]), skin (cutaneous mixed tumor, hidradenoma, spiradenoma, and ACC), and salivary gland (pleomorphic adenoma and ACC). The stained slides were digitized and orientated with H&E images and assessed simultaneously using QuPath. A total of 129, 58, and 56 breast, cutaneous, and salivary gland lesions, respectively, were included. There was poor agreement between WT1-p63 and WT1-calponin (κ < 0.1) in all organs, with absence of WT1 expression in normal salivary gland myoepithelium and most ACCs. There were no significant differences in WT1 expression in myoepithelial cells in normal breast tissue and benign breast neoplasms. Compared to pleomorphic adenomas, cutaneous mixed tumors showed lower WT1 expression (P < .001). WT1 is a less sensitive myoepithelial marker than calponin and p63. However, its unique pattern of expression in salivary gland primary for pleomorphic adenomas/cutaneous mixed tumor can favor a diagnosis of benign salivary gland tumors, particularly in small biopsy specimens.

Pleural metastasis from parotid secretory carcinoma: First report of morphology on effusion cytology, and role of pan-TRK immunohistochemistry

Distant metastasis from salivary gland secretory carcinoma (SC) is rare, with lung and pleura being the most frequent site. While cytological features of SC on fine needle aspirates are well documented, its morphology in serous effusions has not been described. We describe the cytomorphological features on effusion cytology of two patients with ETV6::NTRK3 fusion-positive SC, who subsequently developed pleural metastases. Cytospin preparations of pleural fluid showed tightly cohesive, irregularly shaped and ball-like clusters of large tumor cells with scant to abundant uni- and multi-vacuolated cytoplasm. Nuclei were eccentrically placed, round to oval, vesicular, with finely granular chromatin, irregular nuclear membranes and conspicuous to prominent nucleoli. With these features, the tumors resembled an adenocarcinoma, indistinguishable from a lung primary. Cell blocks from both cases showed tumor fragments, some of which had the hollow appearance of transversely sectioned cell spheres as seen in lung and breast adenocarcinomas. Immunohistochemistry on cell blocks revealed nuclear pan-TRK positivity in both cases. Case 1 also showed focal mammaglobin staining, and TTF1 negativity. Pleural metastases from SC may mimic other adenocarcinomas. As targeted therapy, that is, selective TRK inhibitors are available for treatment of metastatic disease, NTRK3 fusion status is not only diagnostic, but also required to plan treatment. Pan-TRK immunohistochemistry serves as a viable cost-effective, easy to apply surrogate marker for NTRK3 fusion, particularly in diagnostic laboratories lacking easy access to molecular testing on cytological material.

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.

Cystic Salivary Gland Neoplasms: Diagnostic Approach With a Focus on Ancillary Studies

Cystic salivary gland cytology can be challenging due to the fact that a cystic mass can be the clinical presentation of both non-neoplastic and neoplastic conditions. Neoplastic lesions consist of both benign and malignant neoplasms. The cytomorphologic features of these entities can overlap and the cystic background may additionally contribute to the complexity of these lesions and their interpretation. Ancillary studies have been reported in several studies to be beneficial in further characterization of the cellular components and subsequent diagnosis of the cystic lesions of the salivary gland. Fluorescence in situ hybridization, real-time polymerase chain reaction, and next-generation sequencing are now being utilized to detect molecular alterations in salivary gland neoplasms. MALM2 rearrangement is the most common gene fusion in mucoepidermoid carcinoma. PLAG1 rearrangement is present in more than half of pleomorphic adenomas. AKT1:E17K mutation is the key diagnostic feature of the mucinous adenocarcinoma. NR4A3 overexpression is highly sensitive and specific for the diagnosis of acinic cell carcinoma. MYB fusion is noted in adenoid cystic carcinoma. ETV6:NTRK3 fusion is helpful in diagnosis of secretory carcinoma. p16 and human papillomavirus (HPV) studies differentiate HPV-related squamous cell carcinoma from non-HPV-related neoplasms with overlapping features. NCOA4:RET fusion protein is the main fusion in intraductal carcinoma.