Prognosis of primary breast salivary gland-type carcinoma: a propensity score-matching analysis with invasive carcinoma of no special type based on the SEER database for years 2010-2020

BACKGROUND

Primary breast salivary gland-type carcinoma has weak evidence to support its management due to its rare occurrence and limited data regarding its clinicopathological features and prognosis. Therefore, this study aimed to assess clinicopathological features and prognosis for this type of carcinoma diagnosed over the past decade and compared those to the common breast invasive carcinoma of no special type (NST).

METHODS

This study used the Surveillance, Epidemiology, and End Results (SEER) database to extract data regarding primary breast salivary gland-type carcinoma. Using a propensity score-matching approach, the prognosis was compared with invasive carcinoma, NST.

RESULTS

This study included 488 cases of salivary gland-type carcinoma and 375,660 cases of invasive carcinoma, NST, giving an occurrence ratio of 1 to 770. Adenoid cystic carcinoma (81%) formed the majority of salivary gland-type carcinoma, followed by secretory carcinoma (13%). For salivary gland-type carcinoma, acinic cell carcinoma histological type, tumor grade 3, HER2-overexpressed status, and higher AJCC stage groups were significant worse prognostic factors for breast cancer-specific survival in univariate analyses (p < 0.05). Nonetheless, tumor grade 3 and higher AJCC stage groups remained as significant independent prognostic factors in multivariate analysis (p < 0.05). The apparent better breast cancer-specific survival of salivary gland-type carcinoma as compared to that of invasive carcinoma, NST, was diminished following adjustment for differences in baseline clinicopathological features and treatment-related variables.

CONCLUSIONS

This study suggests that when managing primary breast salivary gland-type carcinoma, greater emphasis should be given to the tumor grade and AJCC stage group in addition to acinic cell carcinoma histological type and HER2 overexpression. Conventional prognostic factors are important as salivary gland-type carcinoma had similar prognosis as invasive carcinoma, NST, following adjustment for confounding variables.

Salivary gland secretory carcinoma presenting as a cervical soft tissue mass: a case report

BACKGROUND

Secretory carcinoma (SC) has been described as a distinct salivary gland tumor in the fourth edition of the World Health Organization (WHO) classification of head and neck tumors. SC is generally considered as a slow-growing low-grade malignant tumor, while several cases have been reported with high-grade features, and even metastases in the literature up until now. In this article, a soft tissue SC case is discussed with high-grade microscopic features and neural invasion. A review of the salivary gland SC cases with aggressive behavior is also debated.

CASE PRESENTATION

A 65-year-old Caucasian man presented with a left neck mass for the past six months. The imaging studies demonstrated a very large cystic cervical mass (46 × 23 mm) with papillary projections in the anterolateral aspect of the left neck zone Vb. He underwent left radical neck dissection (level I-V) and was followed up for 12 months with the diagnosis of Secretory carcinoma.

CONCLUSION

Although SC generally has a good outcome, multiple recurrences and unusual metastases may occur, which should be considered by either the pathologists or clinicians.

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.

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.

Secretory carcinoma of salivary glands with NTRK3 break-apart molecular rearrangement: Potential misdiagnosis with mucoepidermoid carcinoma

A woman presented a right submandibular gland lesion with cytologic diagnosis of mucoepidermoid carcinoma. Patient underwent sialoadenectomy en bloc with supraomohyoid neck dissection. Positivity for ETV6-NTRK3 genes fusion on surgical sample led to final diagnosis of secretory carcinoma (SC). Secretory carcinoma has been renamed by WHO in 2017 from mammary-analogue-secretory carcinoma (MASC). Only 649 have been reported until 2019. While cytologic alteration are shared with other neoplasms as the acinic cell and mucoepidermoid carcinomas, ETV6-NTRK3 rearrangement is pathognomonic of SC. Although usually indolent and with low-stage presentation, SC has higher rate of local recurrences and nodal involvement than ACC. Surgical treatment represent the gold standard. Real prevalence of SC is probably underestimated due to the recent WHO 2017 reclassification. While cytologic analysis does not allow to discriminate SC from other malignancies, chromosomal examination is recommended. When low-grade SC is diagnosed, complete surgical resection assures good prognosis.

Secretory Carcinoma of Salivary Glands: A Case Series and Review of Literature

Mammary analogue of secretory carcinoma is a recently described entity in WHO 2017 classification of head and neck tumours. It resembles secretory carcinoma of breast. It usually affects the salivary glands and has an indolent behaviour. We reviewed five cases of Mammary analogue of secretory carcinoma in our institute and compared our results with existing literature. All the patients underwent surgical resections and appropriate adjuvant treatment. Immunohistochemistry is an alternative cost effective tool as compared to genetic testing to differentiate secretory carcinoma from its mimickers. Surgery with adequate margins followed by adjuvant therapy is the treatment of choice.

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

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

Secretory carcinoma of the salivary gland is rich in lactoferrin: a possible lactational-like differentiation?

PURPOSE

It has been hypothesised that secretory carcinoma of the salivary gland (SCsg) might have a lactational-like differentiation. Therefore, we aimed to assess the immunoexpression of breast hormonal receptors and milk-related proteins in cases of SCsg and other salivary gland tumours with prominent secretory activity.

METHODS

Immunohistochemistry against prolactin and growth hormone receptors, lactoferrin, human milk fat globule 1, MUC 1 and MUC4 was performed in twelve cases of SCsg and 47 other salivary gland tumours.

RESULTS

Most cases of SCsg were negative for prolactin and growth hormone receptors. All cases of SCsg showed enhanced membranous-cytoplasmic staining for human milk fat globule 1, a pattern seen in other tumour groups. Only SCsg showed widespread strong staining for lactoferrin, concomitantly in the cell compartment and secretion. The other positive tumour types exhibited restricted staining. MUC1 and MUC4 showed no distinct pattern of expression.

CONCLUSION

Although SCsg failed to demonstrate a complete lactational-like differentiation, lactoferrin showed a distinctive expression pattern in SCsg compared to other tumour types, which makes it a good marker to help in its differential diagnosis.

Two cases report of secretory carcinoma of the salivary gland in the lung: one primary and one metastatic after many years

Background

Secretory carcinoma of the salivary gland (SCSG) is a recently discovered salivary gland tumor that occurs mostly in the major salivary glands and occasionally in the skin, cervix, trachea, etc. Secretory carcinoma of the lung is extremely rare. To our knowledge, this is the third report of SCSG arising as a primary pulmonary tumor. The two SCSG cases reported in this paper are unique in that one was primary and the other was metastasized to the lung.

Case Description

Case 1 is a primary endobronchial tumor in a 66-year-old man. He went to the doctor complaining of fever, cough and yellow phlegm, and his body weight was significantly reduced by 3 kg. The bronchoscope showed the growth of new organisms in the right upper lobe of the lung. Immunohistochemistry of his biopsy specimen was positive for AE1/AE3, Keratin7 (CK7), S-100, mammaglobin, and pan-TRK, but negative for thyroid transcription factor-1 (TTF-1), napsin-A, synaptophysin (SYN), chromogranin A (CGA), and discovered on GIST-1 (Dog-1), and the MKI-67 (Ki-67) proliferation index was 2%. This case lacked the typical ETV-6 gene rearrangement. After one cycle of chemotherapy, the tumor was significantly reduced, and surgical excision was planned. Case 2 was a metastatic secretory carcinoma with a history of parotid pleomorphic adenoma resection 30 years ago and malignant pleomorphic adenoma resection 16 years ago before the study, respectively. He presented with a complaint of a parotid gland mass. Chest CT examination revealed a mass in the upper lobe of the left lung. The biopsy tissue of him exhibited a typical histological appearance under the microscope. Immunohistochemistry was positive for AE1/AE3, CK7, S-100, and mammaglobin; partially positive for estrogen receptor (ER) and pan-TRK; and negative for TTF-1, Napsin-A, SYN, CGA, P63, P40, and Dog-1. The Ki-67 proliferation index was approximately 3%. Fluorescence in situ hybridization (FISH) revealed ETV-6 gene rearrangement. After the diagnosis of SCSG, the patient underwent resection of the lung mass, and there was no recurrence of the lung after 1 month's follow-up.

Conclusions

By examining these two cases, we have a better understanding of the clinicopathological features of secretory carcinoma, which will help to improve the accuracy of pathological diagnosis.

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.

Clinicopathological investigation of secretory carcinoma cases including a successful treatment outcome using entrectinib for high-grade transformation: a case report

Background

Secretory carcinoma (SC) of the salivary gland is a recently described malignant tumor harboring characteristic ETV6-NTRK3 gene fusion. SC generally has a favorable clinical course, and is currently regarded as a low-grade carcinoma. However, a small subset of SCs demonstrates aggressive clinical features with histologically high-grade transformed morphology, the molecular pathogenesis of which has not yet been elucidated. In this study, we performed a clinicopathological and molecular genetic study of patients with SC of the head and neck displaying various clinical characteristics to investigate the differences of pathological and molecular genetics between low-grade and high-grade components of SC.

Case presentation

Three cases with SC of the head and neck, including a conventional low-grade SC and two high-grade transformed SCs are described. High-grade transformed SCs with histological features such as nuclear polymorphism, distinctive nucleoli and increased mitotic activity developed locoregional recurrence and distant metastasis. Immunohistochemical analysis revealed that low- and high-grade components showed different expression patterns for S-100 protein and mammaglobin, whereas all examined components were positive for p-STAT5. p53-positive cell population was markedly higher in one case with high-grade transformed SC. The proliferative activity of high-grade components was markedly increased, with the Ki-67 labeling index ranging up to 30–32%. A fluorescence in situ hybridization study with an ETV6 (12p13) break apart probe revealed split signals in the nuclei in all 3 cases. A targeted next-generation sequencing-based fusion assay demonstrated that all 6 clinical samples from the 3 patients showed the presence of the ETV6-NTRK3 fusion transcripts. One patient with high-grade transformed SC showed a dramatic clinical response to the pan-TRK inhibitor, entrectinib, for the treatment of locoregional recurrence and pulmonary metastasis.

Conclusions

High-grade transformed SC showed aggressive clinical and pathological features with increased Ki-67 labeling index. Molecular genetic study of gene rearrangement appears to be beneficial treatment as the presence of ETV6-NTRK3 translocation may represent a therapeutic target in SC, particularly the high-grade transformed type.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01155-6.

A Case of Secretory Carcinoma in a Patient With a History of Contralateral Medullary Carcinoma

BACKGROUND

Secretory and medullary carcinomas of the breast are rare subtypes of infiltrating ductal carcinoma. The different histological behavior of medullary and secretory carcinomas is correlated with different imaging features on mammography, ultrasound, and magnetic resonance imaging.

CASE REPORT

We report the case of a Caucasian woman in which both subtypes of tumors were diagnosed in an 8-year time interval and evaluate, in antithesis, histopathological and imaging aspects of medullary and secretory carcinoma.

CONCLUSION

To our knowledge, this is the first case reported in literature of secretory carcinoma with a complete imaging tumor evaluation in a patient with a previous contralateral medullary cancer.

Secretory Carcinoma of the Thyroid in a 49-Year-Old Man Treated with Larotrectinib: Protracted Clinical Course of Disease Despite the High-Grade Histologic Features

Secretory carcinoma of the thyroid gland is histologically and genetically similar to its mammary and salivary gland counterparts. Unlike differentiated thyroid carcinomas of follicular cell origin, thyroid SC is not a thyroglobulin-producing tumor and would not be amenable to radioactive iodine therapy. Instead, these carcinomas may respond to targeted therapy with TRK inhibitors, which further emphasizes the importance of their recognition among morphologically similar thyroid entities. Based on eleven cases reported to date, most primary thyroid SC tend to present as locally advanced malignancies and are characterized by frequent recurrences and long-term survival. High-grade histologic features, increased mitotic count and necrosis have been described but their impact on clinical course and outcome remains unclear. We hereby report the case of a primary SC with high-grade features arising in the thyroid of a 49-year-old man, who was treated with Larotrectinib for his second recurrence. The patient achieved a durable response that lasted for 18 months but then he continued to progress and died of disease 181 months after the diagnosis.

Molecular Pathology of Thyroid Tumors: Old Problems and New Concepts

The molecular signatures of many thyroid tumors have been uncovered. These discoveries have translated into clinical practice and are changing diagnostic and tumor classification paradigms. Here, the findings of recent studies are presented with special emphasis on how molecular insights are impacting the understating of RAS mutant thyroid nodules, Hürthel cell neoplasms, and unusual thyroid tumors, such as hyalinizing trabecular tumor, secretory carcinoma of the thyroid, and sclerosing mucoepidermoid carcinoma with eosinophilia. In addition, the utility of detecting actionable molecular alterations by immunohistochemistry in advanced and aggressive thyroid cancer is also discussed.

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."

Triple-negative breast carcinomas of low malignant potential: review on diagnostic criteria and differential diagnoses

Triple-negative breast carcinomas constitute a wide spectrum of lesions, mostly being highly aggressive. Nevertheless, some special histologic subtypes can have low malignant potential. The purpose of the present paper is to review diagnostic criteria and prognostic parameters of breast neoplasms of special histotypes. Specifically, adenoid cystic carcinoma, adenomyoepithelioma, acinic cell carcinoma, mucoepidermoid carcinoma, tall cell carcinoma with reverse polarity, and secretory carcinoma will be discussed. For each tumour, definition and morphological and molecular features, together with prognostic parameters, will be presented. Paradigmatic cases will be illustrated.

Characterization of an ETV6-NTRK3 rearrangement with unusual, but highly significant FISH signal pattern in a secretory carcinoma of the salivary gland: a case report

Background

Fusions of neurotrophic tropomyosin receptor kinase genes NTRK1, NTRK2 and NTRK3 with various partner genes occur in both common and rare tumours and are of paramount predictive value due to the availability of very effective pan-Trk inhibitors like Larotrectinib and Entrectinib. Detection of NTRK fusions is mainly performed by fluorescence in situ hybridization (FISH) and next generation sequencing (NGS). The case described here showed a very unusual, but highly significant FISH signal pattern with an NTRK3 break apart probe, indicative of a functional NTRK3 rearrangement.

Case presentation

We describe here the case of a male patient who was originally diagnosed with an adenocarcinoma of the parotid gland without evidence of metastases. After the development of multiple lung metastases, an extensive immunohistochemical and molecular examination of archived tumour tissue including analysis of NTRK was performed. NTRK expression was detected by immunohistochemistry (IHC) and then comprehensively analysed further by FISH, quantitative reverse transcription PCR (RT-qPCR), and NGS. NTRK3 break apart FISH showed multiple and very faint single 3′ signals in addition to fusion signals. Quantitative reverse transcription PCR and NGS confirmed an ETV6:exon5-NTRK3:exon15 fusion. Diagnosis was therefore revised to metastatic secretory carcinoma of the salivary gland, and the patient subsequently treated with Larotrectinib, resulting in persisting partial remission.

Conclusions

Our findings underline the importance to be aware of non-canonical signal patterns during FISH analysis for detection of NTRK rearrangements. Very faint single 3′ signals can indicate a functional NTRK rearrangement and therefore be of high predictive value.

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.

An Underappreciated Cytomorphological Feature of Secretory Carcinoma of Salivary Gland on Fine Needle Aspiration Biopsy: Case Report with Literature Review

Secretory carcinoma (SC) of salivary gland, previously known as mammary analogue secretory carcinoma, is a rare low-grade malignancy harboring a diagnostic ETV6-NTRK3 gene fusion. SC of salivary gland shares histopathological, immunohistochemical and genetic characteristics with SC of the breast. There are several previous cytomorphological characterizations of SC of salivary gland reported in the literature. The most commonly reported patterns are of epithelial clusters with papillary architectural features, or of single dispersed epithelial cells on a background of abundant histiocytes. Tumor cells exhibit vacuolated eosinophilic cytoplasm and round to oval nuclei with regular nuclear contours and inconspicuous or small nucleoli. The cytomorphology of SC may closely mimic that of acinic cell carcinoma or low-grade mucoepidermoid carcinoma. Moreover, when cohesive epithelial clusters do not appear on the smears, it may be very difficult to distinguish dispersed tumor cells from histiocytes. In this article, we review the literature pertaining to SC cytomorphology and we report a fine needle aspiration biopsy case of SC in salivary gland showing well-defined intracytoplasmic hyaline globules, a feature that has not been previously reported. This novel cytomorphological feature may be helpful in distinguishing the tumor cells of SC from histiocytes and from other low-grade salivary gland tumors.

Locally Recurrent Secretory Carcinoma of the Breast with NTRK3 Gene Fusion

Enhanced understanding of the molecular events underlying oncogenesis has led to the development of "tumor-agnostic" treatment strategies, which aim to target a tumor's genomic profile regardless of its anatomic site of origin. A classic example is the translocation resulting in an ETV6-NTRK3 gene fusion, a characteristic driver of a histologically diverse array of cancers. The chimeric ETV6-NTRK3 fusion protein elicits constitutive activation of the tropomyosin receptor kinase (TRK) C protein, leading to increased cell survival, growth, and proliferation. Two TRK inhibitors, larotrectinib and entrectinib, are currently approved for use in the metastatic setting for the treatment of advanced solid tumors harboring NTRK fusions. Here we report a rare case of recurrent secretory carcinoma of the breast (SCB) with NTRK3 gene fusion. Whereas most cases of SCB represent slow-growing tumors with favorable outcomes, the case detailed here is the first to the authors' knowledge of recurrence within 1 year of surgery. We review the molecular findings and potential clinical significance. KEY POINTS: The translocation resulting in the ETV6-NTRK3 gene fusion is a known oncogenic driver characteristic of secretory carcinoma of the breast (SCB). Whereas most cases of SCB represent slow-growing tumors with favorable outcomes, the case here with ETV6-NTRK3 gene fusion had local recurrence within 1 year of surgery. Two tropomyosin receptor kinase (TRK) inhibitors, larotrectinib and entrectinib, are approved to treat NTRK fusion-positive tumors, demonstrating sustained high overall response rates in the metastatic setting. Approval of TRK inhibitors necessitates optimization of NTRK fusion detection assays, including detection with liquid biopsies.

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.

A case of metachronous bilateral secretory carcinoma

Secretory carcinoma (SC) was first recognized as a distinct salivary malignancy in 2010. In the nine years since its recognition, there have been multiple reports of SC of the major and minor salivary glands, as well one case of tongue base involvement. Here we present the first reported case of bilateral SC. The first tumor, diagnosed before the recognition of SC, was classified as mucoepidermoid carcinoma. After the contralateral parotid tumor was diagnosed as SC in 2016, the two histologies were compared, and the mucoepidermoid carcinoma was reclassified as SC. In this report, we describe our patient’s clinical course and review the SC literature, with a focus on pathologic diagnosis and clinical prognosis.

NTRK fusions and Trk proteins: what are they and how to test for them

The NTRK genes include a family of three genes, NTRK1, NTRK2, and NTRK3, which are associated with fusions with a variety of partner genes, leading to upregulation of three proteins, TrkA, TrkB, and TrkC. NTRK fusions occur in a variety of solid tumors: at high incidence in secretory carcinoma of the breast and salivary glands, congenital mesoblastic nephroma, and infantile fibrosarcoma; at intermediate incidence in thyroid carcinoma, particularly postradiation carcinomas and a subset of aggressive papillary carcinomas, Spitzoid melanocytic neoplasms, pediatric midline gliomas (particularly pontine glioma), and KIT/PDGFRA/RAS negative gastrointestinal stromal sarcomas; and at a low incidence in many other solid tumors. With new FDA-approved treatments available and effective in treating patients whose tumors harbor NTRK fusions, testing for these fusions has become important. A variety of technologies can be used for testing, including FISH, PCR, DNA, and RNA-based next-generation sequencing, and immunohistochemistry. RNA-based next-generation sequencing represents the gold standard for the identification of NTRK fusions, but FISH using break-apart probes and DNA-based next-generation sequencing also represent adequate approaches. Immunohistochemistry to detect increased levels of Trk protein may be very useful as a screening technology to reduce costs, although it alone does not represent a definitive diagnostic methodology.

Secretory carcinoma ex pleomorphic adenoma of the submandibular gland: An immunohistochemical study

Male patient 60-year-old was referred from another service for expert review of a lesion in the submental region. Pathological review revealed morphological features compatible with salivary gland Secretory carcinoma (SC) in cervical lymph node. The patient underwent removal of the left submandibular gland, left neck dissection and biopsy of left labial commissure region. Anatomopathological examination was observed tumor cells arranged in a solid and ductal/cystic pattern, with abundant droplets of secreted eosinophilic material within these structures and extensive hyalinized area, which presented few cells arranged in a ductal pattern. It was possible to observe the presence of extracapsular extension of neoplastic cells > 6 mm, base on this aspects, Carcinoma ex pleomorphic adenoma was suspected. Immunohistochemical panel showed positivity for mammaglobin, s100, CK7, and adipophilin and negativity for myoepithelial markers and PAS in SC cells. The myoepithelial markers showed positivity for residual cellsin hyalinized area, corresponding to residual Pleomorphic adenoma (PA). In view of these findings, the diagnosis of Secretory carcinoma ex pleomorphic adenoma (SCXPA) was established.

A case report of surgical resection of secretory carcinoma in the maxillary and ethmoid sinus

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Mammary Analogue Secretory Carcinoma (MASC) is a head and neck tumour that was first defined in 2010.

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Only two cases of Secretory Carcinoma have reported in the sinuses.

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We present a case of a Secretory Carcinoma presenting in the maxillary and ethmoid sinuses.

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The tumour treated with surgical resection and re-resection and was disease free at 1 year follow up.

Introduction

Secretory Carcinoma is a recently discovered head and neck tumour. Surgical resection is generally the first line of treatment with neck dissection, radiation, and chemotherapy decided based on clinical, radiological, and histological parameters. We present a case of a Secretory Carcinoma presenting in the maxillary and ethmoid sinuses.

Case

A 39-year-old male presented with left nasal obstruction and chronic rhinosinusitis beginning after surgical repair of the mandible and maxilla due to facial trauma. A CT scan of the head showed soft tissue density in the left maxillary sinus extending through the ethmoid sinus and posterior nasal cavity. Functional endoscopic sinus surgery (FESS) was performed to remove the obstructing lesion. Biopsy was analysed and the main differential diagnosis was between a non-intestinal type adenocarcinoma of nasal origin and a salivary carcinoma.

Discussion

To our knowledge, there have only been two cases of Secretory Carcinoma reported in the sinuses: one case in the ethmoid sinus and the other in the maxillary sinus. This is the first to report follow up at 1 year.

Conclusion

Both MRI and exam showed no evidence of recurrent disease at one year follow up. This report aims to further the understanding of Secretory Carcinoma tumours in the sinuses. Our report could be used to further understand diagnostic criteria for Secretory Carcinoma in the sinuses as well as treatment outcomes for surgical resection without adjuvant treatment.

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.

Pan-tropomyosin receptor kinase immunoreactivity, ETV6-NTRK3 fusion subtypes, and RET rearrangement in salivary secretory carcinoma

Salivary secretory carcinoma (SASC) is frequently associated with ETV6-neurotrophic tyrosine receptor kinase (NTRK) 3 fusion and more rarely with RET, MET, or ALK rearrangement. We aimed to elucidate the potential diagnostic utility of pan-tropomyosin receptor kinase (Trk) immunohistochemistry and its relationship with the fusion gene subtype in SASC. We examined 33 cases of SASC for immunoexpression of pan-Trk, ALK and ROS1, and gene rearrangement of the ETV6, NTRK3, and RET genes using fluorescence in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR). Thirty (90.9%) of 33 SASCs harbored ETV6-NTRK3 fusion gene transcripts by RT-PCR and/or both ETV6 and NTRK3 gene rearrangements by FISH, and 3 cases (9.1%) had RET gene rearrangement. Most NTRK3-rearranged SASCs (27/33 cases; 81.8%) had conventional ETV6 exon 5-NTRK3 exon 15 fusion, whereas 2 cases (6.1%) had both the conventional fusion and a novel ETV6 exon 4-NTRK3 exon 15 fusion variant. In the remaining one case (3%), only FISH revealed both ETV6 and NTRK3 rearrangements, suggesting an ETV6-NTRK3 fusion with an as yet undetermined break point. All 30 SASCs with ETV6-NTRK3 fusion and/or NTRK3 rearrangement showed nuclear and cytoplasmic immunoreactivity for pan-Trk. In contrast, 3 SASCs with RET rearrangement showed negative or only weak cytoplasmic staining for pan-Trk. There was no case harboring ALK and ROS1 rearrangements. All 17 non-SASC tumors were negative for pan-Trk. The results suggest that nuclear and cytoplasmic immunoreactivity for pan-TRK may be helpful to identify ETV6-NTRK3-fused SASCs and to distinguish them from RET-rearranged SASCs and morphological mimics.

NR4A3 Immunohistochemistry Reliably Discriminates Acinic Cell Carcinoma from Mimics

Acinic cell carcinoma (AciCC) harbors a recurrent t(4;9)(q13;q31) translocation, which leads to upregulation of Nuclear Receptor Subfamily 4 Group A Member 3 (NR4A3). Previous work on tissue microarrays suggests that NR4A3 immunohistochemistry (IHC) may be useful in the diagnosis of AciCC. Thus far, only a single study has evaluated the utility of NR4A3 immunohistochemistry (IHC) in the diagnosis of AciCC, using a tissue microarray to assess most non-AciCC tumor types. Herein we evaluate the diagnostic performance of NR4A3 IHC for AciCC in a large cohort of 157 salivary gland tumors, using whole tissue sections. The cohort consisted of 37 AciCC (6 of them (16%) with high grade transformation), 30 secretory carcinomas (SC), and 90 additional salivary gland tumors, including mucoepidermoid carcinomas (MEC), polymorphous adenocarcinomas (PAC), pleomorphic adenomas (PA), salivary duct carcinomas (SDC), and adenoid cystic carcinomas (AdCC). NR4A3 nuclear staining by IHC was considered positive if present in more than 5% of tumor cells. Overall, 92% of AciCC (34/37) expressed NR4A3 by IHC, with strong (89%) or moderate (3%) nuclear staining, yielding a sensitivity of 92%. IHC detected NR4A3 expression in all cases of recurrent/metastatic AciCC and tumors with high grade transformation. Importantly, all SC were negative for NR4A3 IHC, with no staining in 28/30 cases and weak focal staining, in < 5% of cells, in 2/30 (7%). Similarly, all MEC (20/20), SDC (20/20) and AdCC (10/10) were negative for NR4A3 by IHC, as were most PA (18/20; 15%) and PAC (18/20; 5%). Two PA and two PAC showed multifocal expression of NR4A3 in more than 5% of cells, of weak intensity in 3 cases and moderate in 1 PAC, yielding an overall specificity of 97% for NR4A3 IHC for the diagnosis of AciCC. In conclusion, NR4A3 is a highly sensitive and specific immunohistochemical marker for AciCC; moderate to strong and/or diffuse NR4A3 expression is a consistent and diagnostic feature of AciCC.

Concurrent Identification of Novel EGFR-SEPT14 Fusion and ETV6-RET Fusion in Secretory Carcinoma of the Salivary Gland

Salivary gland secretory carcinoma, also termed mammary analogue secretory carcinoma (MASC), is a recently described salivary gland neoplasm with characteristic histomorphologic findings similar to those of secretory carcinoma of the breast and harboring recurrent ETV6-NTRK3 fusions. Recent findings have expanded the molecular profile of salivary gland secretory carcinoma to include multiple novel ETV6 fusion partners, including RET, MET, and MAML3. Here, we report a case of cystic MASC with cribriform and papillary histology harboring two gene fusions, ETV6-RET and EGFR-SEPT14, identified by targeted RNA sequencing. The presence of the rearrangements was confirmed by FISH, RT-PCR, and Sanger sequencing. This is the first EGFR-SEPT14 fusion reported in secretory carcinoma as a single event or in association with an ETV6 rearrangement. This finding adds to the expanding molecular profile of this tumor entity, and may translate into novel treatment strategies.

Secretory carcinoma around Stensen's duct misdiagnosed as salivary duct cyst

Secretory carcinoma (SC) of the salivary gland was identified in 2010, and it is characterized by a specific ETV6 gene arrangement. The most common primary site for SC is the parotid gland; however, SC around the Stensen's duct is rare. Here we describe a rare case of a SC around the Stensen's duct that was initially misdiagnosed as a salivary duct cyst. A 59-year-old woman presented with a mass in the region of the left parotid papilla. Magnetic resonance imaging (MRI) revealed a well-circumscribed lesion and enhancement with a rim and an inner wall-like part that appeared in the late phase. Based on the initial clinical and imaging findings, a salivary duct cyst of the parotid gland was diagnosed. However, the lesion was histopathologically diagnosed as a SC based on immunohistochemical findings. The tumor cells showed diffuse positive staining for AE1/AE3, vimentin, and mammaglobin and focal positive staining for S-100 protein, SOX-10, and DOG-1. Fluorescence in-situ hybridization revealed ETV6 gene rearrangement in the tumor. In cases of cystic lesions around the Stensen's duct, clinicians should bear in mind that the possibility that they could be minor salivary gland cancers, such as SC.

Expression of upstream and downstream targets of mTOR pathway in seven cases of secretory carcinoma of salivary gland origin

PURPOSE

To investigate the expression of upstream and downstream targets of mTOR signalling pathway in the secretory carcinoma of salivary gland origin (SCsg).

METHODS

Seven cases of secretory carcinoma diagnosed by a combination of immunohistochemistry and/or molecular testing were retrieved from our pathology files. For comparison purposes, 27 other salivary carcinomas were selected. Immunohistochemical staining was performed against phospho-Akt, PTEN, phospho-mTOR, phospho-4E-BP, eIF4E and phospho-S6 ribosomal protein.

RESULTS

With the exception of Akt, all the other proteins were present at some level in the SCsg and in other salivary carcinomas. PTEN was diffusely expressed in 57.1% of SCsg, but only in 14.8% of other salivary carcinomas. mTOR is expressed in more than half of the cases both for SCsg and other salivary tumour types. Most cases of SCsg showed negative expression for S6 ribosomal protein (71.4%) and 4E-BP1 (57.1%). For both groups evaluated, eIF4E was the most expressed protein.

CONCLUSION

SCsg shows different expression patterns for the mTOR signalling molecules, but only eIF4E was highly expressed. This may suggest alternative signalling pathways other than Akt and mTOR in this group of tumours.

Retrospective Study of Buccal Mucosal Salivary Neoplasms

Salivary gland neoplasms of the buccal mucosa are relatively rare and often present with an unusual histopathologic profile when compared with other intraoral locations. We present a series of minor salivary gland neoplasms of the buccal mucosa and discuss demographics, clinical presentation, and histologic findings. An IRB approved retrospective search of University of Florida Oral Pathology Biopsy Service archive from 1994 to 2018 for all salivary gland neoplasms of the buccal mucosa was undertaken. Data related to age, gender, clinical presentation, diagnosis, and category of neoplasm recorded. Review for consensus of diagnosis and immunohistochemical (IHC) testing on current diagnostic standards was performed and diagnoses updated based on results. Of 66 cases identified majority were females (72.7%) and age mean was 63 years. Benign tumors were 56.06% and 43.94% malignant, with Mucoepidermoid carcinoma (MEC) being commonest (26/66, 39.4%), followed by canalicular adenoma (CLA) (14/66, 21.2%), ductal papilloma (DP) (10/66, 15.2%), cystadenoma (CA) (8/66, 12.1%), basal cell adenoma (BCA) (4/66, 6.1%), and 1(1.5%) each for pleomorphic adenoma (PA), secretory carcinoma (SC), adenoid cystic carcinoma (ACC) and adenocarcinoma not otherwise specified (ACNOS). This study with respect to demographics and percentage of benign and malignant buccal mucosal salivary gland neoplasms is in conformity with the literature. It underscores the fact that both benign and malignant salivary gland neoplasms should be included in the differential diagnosis of submucosal buccal masses. Future larger multicenter studies with detailed treatment and outcomes data may aid and assist in further understanding the behavior, diverse histomorphology and prognosis of these neoplasms.

Usefulness of immunohistochemistry to distinguish between secretory carcinoma and acinic cell carcinoma in the salivary gland

Secretory carcinoma (SC) of the salivary gland is a relatively newly described disease, separate from acinic cell carcinoma (ACC), which frequently displays ETV6-NTRK3 gene fusion. However, the differences between SC and ACC remain unclear. Here, histological reevaluation of 12 formerly diagnosed ACC cases was performed, which yielded a new diagnosis of SC in four cases due to a lack of obvious acinar-like cells. Immunohistochemically, phosphorylated signal transducer and activator of transcription 5 (p-STAT5) was expressed in SC but not in ACC, whereas discovered on GIST-1 (DOG1) was expressed in ACC but not in SC. Molecular analysis was possible in three SC cases, of which two showed the ETV6-NTRK3 fusion transcript on reverse-transcription polymerase chain reaction, as well as breaks in the ETV6 gene on fluorescence in situ hybridization. However, the remaining SC cases did not show this fusion transcript. Recently, several reports have suggested that SC might not be adequately diagnosed if the focus is placed solely on the ETV6-NTRK3 fusion gene due to genetic diversity. In this regard, immunohistochemistry of p-STAT5 and DOG1 is expected to be a useful alternative diagnostic tool to discriminate SC from ACC.

Concurrent presence of secretory carcinoma and Warthin's tumor in ipsilateral parotid gland

BACKGROUND

The presence of synchronous benign and malignant salivary gland neoplasms is very rare. The authors present a previously unreported combination of Secretory Carcinoma (SC) and Warthin's Tumor (WT) within the same parotid gland.

METHODS

The patient presented with increasingly painful enlargement of the left parotid gland. CT scan with contrast revealed a heterogeneous solid/cystic mass in the superficial lobe. Fine needle aspiration cytology favored pleomorphic adenoma (PA) and patient underwent superficial parotidectomy without complication.

RESULTS

Final pathology revealed concomitant presence of SC and WT. Stains were positive for S100 and mammaglobin, and FISH revealed the presence of t(12;15) (p13;q25) translocation, resulting in the ETV6-NTRK3 fusion gene.

CONCLUSION

It is important for surgeons and pathologists to note the potential for co-existing benign and malignant pathology within the same salivary gland, as this can have an impact on management and prognosis for patients.

Pan-Trk immunohistochemistry reliably identifies ETV6-NTRK3 fusion in secretory carcinoma of the salivary gland

Secretory carcinoma of the salivary gland is a newly recognized entity that morphologically resembles breast secretory carcinoma and has a characteristic t(12;15)(p13;q25) ETV6-NTRK3 translocation. Fluorescence in situ hybridization (FISH) or reverse transcription polymerase chain reaction (RT-PCR) analyses can detect the ETV6-NTRK3 fusion; however, both tests are expensive and not widely available. In this study, we aimed to determine whether pan-Trk immunohistochemistry (IHC) could detect ETV6-NTRK3 fusions as reliably as RT-PCR and FISH. We performed pan-Trk IHC in 70 salivary gland cancer samples, including secretory carcinomas, acinic cell carcinomas, and hybrid carcinomas. Nineteen tumors exhibited positive pan-Trk staining, including 16 secretory carcinomas, 2 hybrid carcinomas with a secretory carcinoma component, and 1 acinic cell carcinoma. Pan-Trk IHC staining was localized in the nucleus in 16 (84.2%) cases and in the cytoplasm and/or membrane in 3 (15.8%) cases. RT-PCR analysis for the ETV6-NTRK3 transcript was conducted in 45 samples; the fusion transcript was present in 11 of 12 secretory carcinomas and absent in 32 acinic cell carcinomas and 1 mucoepidermoid carcinoma. Pan-Trk IHC was positive in 10 of 11 salivary tumors that were positive for ETV6-NTRK3 by RT-PCR and negative in all 34 tumors that were negative for the fusion by RT-PCR. Therefore, in comparison with RT-PCR, pan-Trk IHC had a sensitivity of 90.9% and specificity of 100%. In conclusion, our data showed that pan-Trk IHC is a reasonable screening test for diagnosing secretory carcinoma of the salivary gland.

Pure secretory carcinoma in situ: a case report and literature review

Background

Secretory breast carcinoma is an exceptionally rare type of breast carcinoma. Only 5 cases of pure secretory carcinoma in situ have been reported in English literature. Herein, we reported a rare case of pure secretory breast carcinoma in situ.

Case presentation

The patient is a 38-year-old female with bloody discharge from the left nipple. Microscopically, the terminal-duct lobular units were enlarged and filled with tumor cells. The tumor cells were arranged in cystic, microcystic, solid and papillary pattern and formed a honeycomb-like appearance. The presence of intracellular and extracellular eosinphilic PAS-positive material was the most remarkable feature. Immunohistochemically, myoepithelial markers highlighted the complete presence of myoepithelial cells around the tumour nests. Tumour cells were strongly positive for S-100 and CK5/6, negative for ER, PR and HER2. Fluorescence in situ hybridization analysis showed ETV6-NTRK3 fusion.

Conclusion

Secretory carcinoma in situ shares the same morphological, immunohistochemical and molecular features with invasive secretory carcinoma except that the papillary growth pattern is more common in the introductal components. Cautions should be taken to distinguish secretory carcinoma in situ from other introductal lesions. Our report is an important supplement to the morphology spectrum of secretory breast carcinoma.

Clinical characteristics of acinic cell carcinoma and secretory carcinoma of the parotid gland. Eur Arch Otorhinolaryngol. 2019;276:3461-3466. [PMID: 31440815 DOI: 10.1007/s00405-019-05604-4]

PURPOSE

Mammary analogue secretory carcinoma (SC) of the parotid gland is a relatively uncommon cancer associated with the ETV6-NTRK3 fusion product similar to breast cancer. The clinical characteristics and outcome of treatment were reviewed for patients with this tumor at our hospital.

METHODS

In this retrospective case series, 24 patients with a diagnosis of acinic cell carcinoma (AcCC) of the parotid gland were classified as having either SC or AcCC based on analysis of the ETV6-NTRK3 fusion gene. These two groups were compared with respect to their clinical and imaging characteristics (MRI/US), cytologic findings, accuracy of fine-needle aspiration cytology and frozen section, treatment outcomes, and immunohistochemical findings.

RESULTS

Based on re-classification by ETV6-NTRK3 fusion gene analysis, the diagnosis was SC in 14 patients and AcCC in 10 patients. The SC group had a significantly higher proportion of male patients and was also significantly younger than the AcCC group. Imaging studies revealed that SC was significantly more likely to show internal heterogeneity. Correct grading of both tumors was comparable by fine needle aspiration, with the rate being 60% for AcCC and 50% for SC. Diagnosis by frozen section biopsy diagnosis obtained the correct grade in 90% of the AcCC group and 93% of the SC group.

CONCLUSIONS

In 24 patients previously diagnosed with AcCC, re-analysis of the ETV6-NTRK3 fusion product indicated that 14 patients actually had SC. Although AcCC and SC show similarities of their biological aggressiveness and prognosis, patients with SC were significantly more likely to be male and younger.

Immunohistochemical expression of mammaglobin in salivary duct carcinomas de novo and salivary duct carcinoma ex pleomorphic adenoma

Mammaglobin is expressed in breast and salivary gland secretory carcinomas; however, its expression in salivary duct carcinomas (SDCs) still not well established. Therefore, the aim of this study was to investigate the presence and distribution of mammaglobin immunoexpression in SDC ex-PA in different phases of the adenoma to carcinoma sequence evaluating its possible involvement in carcinogenesis and tumor progression, as well as to determine its expression in SDC de novo. Mammaglobin immunohistochemistry was performed in 84 SG tumors, including 41 pleomorphic adenomas (PA) without malignant transformation, 13 intracapsular SDC ex-PA, 5 frankly invasive SDC ex-PA, 25 SDC de novo and 10 secretory carcinomas. The reactions were qualitatively analyzed and digitally scored. Positive immunostaining for mammaglobin was observed in 37 out of 84 SG tumors evaluated (44.1%), but strong staining was consistently seen only in secretory carcinomas, SDC de novo and frankly invasive SDC ex-PA, while it was weaker in intracapsular SDC ex-PA and PA. In PA, mammaglobin expression was significantly associated with recurrence. This study has confirmed that the mammaglobin is commonly expressed in SDC de novo and secretory carcinomas. Its expression was higher in SDC ex-PA than in PA, suggesting that mammaglobin may play a role in its malignant transformation.

Novel gene fusions in secretory carcinoma of the salivary glands: enlarging the ETV6 family

Secretory carcinoma (SC) of the salivary gland is a low-grade malignancy associated with a well-defined clinical, histologic, immunohistochemical, and cytogenetic signature. Although the t(12;15) (p13;q25) translocation resulting in an ETV6-NTRK3 gene fusion is well documented, advances in molecular profiling in salivary gland tumors have led to the discovery of RET as another ETV6 gene fusion partner in SC. Here, we applied an RNA-based next-generation sequencing (NGS) approach for fusion detection on 14 presumed SC. The cases included 7 SC with classic ETV6-NTRK3 gene fusion and 3 SC harboring ETV6-RET gene fusion. In addition, 2 cases revealed a NCOA4-RET gene fusion and were subsequently reclassified as intraductal carcinomas. One case with an unusual dual-pattern morphology revealed a novel translocation involving ETV6, NTRK3, and MAML3 gene rearrangements. Interestingly, no ETV6-NTRK3 or ETV6-RET SC was ever documented to have this unique dual-pattern morphology or harbor a MAML3 mutation. The remaining case had no detected chromosomal abnormalities. Advances in molecular profiling of SC have led to the discovery of novel fusion partners such as RET and now MAML3. Further molecular characterization of salivary gland neoplasms is needed as these mutations may present alternative therapeutic targets in patients with these tumors.

Cytopathologic Features of Secretory Carcinoma of Salivary Gland: Report of Two Cases

Secretory carcinoma of the salivary gland (SC) is a newly introduced rare salivary gland tumor that shares histological, immunohistochemical, and genetic characteristics with secretory carcinoma of the breast. Here, we report the cytologic features of two cases of SC confirmed by surgical resection. In these two cases, SC was incidentally detected in a 64-year-old female and a 56-yearold male. Fine needle aspiration cytology revealed nests of tumor cells with a papillary or glandular structure floating in mucinous secretions. The tumor cells demonstrated uniform, round, smooth nuclear contours and distinct nucleoli. Multiple characteristic cytoplasmic vacuoles were revealed. Singly scattered tumor cells frequently showed variable sized cytoplasmic vacuoles. The cytopathologic diagnosis of SC should be considered when characteristic cytological findings are revealed. Further immunohistochemistry and gene analyses are helpful to diagnose SC.

Secretory carcinoma: the eastern Canadian experience and literature review

Background

Secretory Carcinoma (SC) is a recently described malignancy affecting salivary glands of the head and neck, with a paucity of evidence regarding the natural history, morbidity, and mortality. This study aimed to investigate the current treatment options utilized for SC, as well as its presentation and outcomes.

Methods

This study is a retrospective case series and includes patients diagnosed with SC at four Maritime Canadian institutions. Literature review of patient outcomes following treatment of SC is also included.

Results

Thirteen patients were identified. Parotid was the most common subsite (69%), followed by minor salivary gland (23%) and submandibular gland (8%). All patients were S100 positive and had at least one additional positive confirmatory stain, including mammaglobin, CK7, or vimentin. Two patients had N2b disease. All patients were treated with primary surgery, and four were offered adjuvant radiotherapy. There was one instance of locoregional recurrence, and one of metastasis. Three patients displayed perineural invasion on pathology, and one patient displayed lymphovascular invasion.

Conclusion

Secretory Carcinoma remains understudied regarding its natural history, presentation, and treatment options. This study is the largest single case series in Canada, and highlights the young age and possible aggressiveness of SC. As well, we provide the most comprehensive literature review to date, with a focus on treatment and outcomes for this disease entity.

Electronic supplementary material

The online version of this article (10.1186/s40463-018-0315-6) contains supplementary material, which is available to authorized users.

[Secretory carcinoma of the breast: clinical histopathologic and biological behaviors]

Objective: To investigate the clinicopathological and immunohistochemistrical features of secretory carcinoma of the breast (SCB), as well as its diagnosis and prognosis. Methods: Five cases of SCB were collected and specimens were fully drawn. Microscopic pathology examinations and immunohistochemistry(SP method)were performed. Results: Five cases were all female patients aged from 31 to 54 years old (with an average age of 38 years), and all patients initially presented with the painless breast lump, often near the areola. Macroscopically, all the tumors were relatively circumscribed, with a mean diameter of 2.1 cm(1.2-3.0 cm). Histologically, the tumors revealed different patterns (microcystic, solid, ductal, and so forth) and appeared large amounts of intracellular and extracellular eosinophilic PAS- and AB-PAS- positive secretory materials, as well as the granular eosinophilic cytoplasm. Immunohistochemistrically, the tumor cells were strongly positive for epithelial membrane antigen (EMA) and S-100. Three cases had negative expression for estrogen receptor (ER) and progesterone (PR), and two cases had weakly focal expression. Human epidermal growth factor receptor 2 (HER2) and P53 were negative, while only one case had weakly focal expression. The tumors were positive for CK7, CK5/6, CD10, but they were negative for CEA, smooth muscle actin (SMA) and P63 . The proliferation index of Ki-67 was 5%-8%. There was no patient with metastasis of the tumor in axillary lymph node. Except 1 case lost follow-up, and the rest had no recurrence or distant metastasis. Conclusions: SCB is very rare, with low malignancy, and has better prognosis, but it is usually classified as triple-negative breast cancer because of the immune phenotype. The correct diagnosis of this lesion depends on clinical characteristics, morphology and immunohistochemistry.

[Clinicopathologic and molecular genetic analysis of secretory carcinoma of salivary gland]

Objective: To investigate the clinicopathologic and molecular genetic features of secretory carcinoma of salivary gland (SCSG). Methods: Six cases of SCSG were collected from Zhejiang Provincial People's Hospital from January 2011 to March 2018. The clinical, histopathological and immunohistochemical features were analyzed and fluorescence in situ hybridization (FISH) was used to detect ETV6 gene rearrangement. Results: Four out of 6 tumors originated in the parotid gland and one of each in the minor salivary glands of soft palate and the buccal mucosa. Grossly, 4 cases were solid and 2 were partially cystic with maximum diameter ranging from 1.0 to 4.0 cm. Microscopically, 5 tumors showed typical features of low grade SCSG with tumor divided by thin fibrous septa into lobules composed of solid acinar, microcystic, follicular and papillary structures with abundant extracellular mucinous secretions. The tumor cells had cuolated or hobnail cytoplasm with low-grade nuclei and scarce mitoses. Perineural invasion was present in 1 case. The remaining tumor showed about 30% of the tumor areas with high-grade transformation characterized by proliferation of a distinct population of anaplastic cells arranged in irregular glandular, small nested and single cell patterns that were surrounded by desmoplastic stroma and invaded into surface mucosa with ulceration. Immunohistochemistry showed that all 6 tumors had diffuse and strong reactivities to S100 protein and cytokeratin 7, and 4 cases showed focal reactivity to gross cystic disease fluid protein 15 (GCDFP15), all were negative for discovered on gist 1 (DOG1), cytokeratin 20, p63 and calponin. High grade transformation cases were analysed, the high grade SCSG components showed a significantly increased Ki-67 index and cyclin D1 positive tumor cells compared to the conventional SCSG components. FISH analyses showed that 4 cases had ETV6 gene rearrangement. Eleven to seventy one months' follow-up showed no evidence of tumor recurrence nor metastasis. Conclusions: SCSG harbors characteristic genetic abnormalities with ETV6 gene rearrangement and typically shows a low grade morphology with occasionally, high grade transformation can be present.

Hemorrhage of MRI and Immunohistochemical Panels Distinguish Secretory Carcinoma From Acinic Cell Carcinoma

OBJECTIVES

Secretory carcinoma (SC, mammary analogue secretory carcinoma) is a salivary gland tumor with ETV6-NTRK3 gene fusion, and its differential diagnosis includes acinic cell carcinoma (ACC). As hemorrhage is often seen in SC, we hypothesized that magnetic resonance imaging (MRI) and immunohistochemical analyses could distinguish SC from ACC.

STUDY DESIGN

Retrospective study.

METHODS

We used ETV6-NTRK3 gene fusion analyses to reclassify 19 parotid gland tumors that had previously been diagnosed as SC or ACC, and then investigated hemorrhage in both hematoxylin-eosin (H&E)-stained sections and MRIs, and immunohistochemical expression of S-100, mammaglobin, DOG1, and α-amylase.

RESULTS

The 19 tumors were genetically reclassified into 11 (58%) SC and 8 (42%) ACC. Combined S-100 and mammaglobin were specific for SC; whereas DOG1 was specific for ACC, and α-amylase was expressed only in 4 ACC cases (50%). H&E staining showed hemorrhage with hemosiderin deposition in all SC cases, and T2-weighted MRI showed hypointense areas in all investigated SC cases, but not in ACC.

CONCLUSION

Hemorrhage with hemosiderin deposition is frequently present in SC, and hemorrhage findings in MRI and an immunohistochemical panels for S-100, mammaglobin and DOG1 can distinguish SC from ACC.

LEVEL OF EVIDENCE

3b.

Clinicopathological characteristics and outcome of 31 patients with ETV6-NTRK3 fusion gene confirmed (mammary analogue) secretory carcinoma of salivary glands

OBJECTIVES

In 2010, a new subtype of salivary gland cancer (SGC), (mammary analogue) secretory carcinoma (SC), was defined, characterized by the ETV6-NTRK3 fusion gene. As clinical behavior and outcome data of this histological subtype tumor are still sparse, we aimed to describe the clinicopathological course and outcome of a series of translocation positive SC patients.

PATIENT AND METHODS

We re-evaluated the pathological diagnosis of a subset of SGCs, diagnosed in 4 of 8 Dutch head and neck centers. Subsequently, tumors with a morphological resemblance to SC were tested for the ETV6-NTRK3 fusion gene using RT-PCR. Furthermore, patients prospectively diagnosed with SC were included. The clinical characteristics and outcomes were retrieved from the patient files.

RESULTS

Thirty-one patients with ETV6-NTRK3 fusion gene positive SC were included. The median age was 49 years, 17 patients (55%) were male. Eighteen tumors (58%) arose in the parotid gland. One patient presented with lymph node metastasis. All patients underwent tumor resection and 4 patients had a neck dissection. Four patients had re-resection and 15 patients (48%) received postoperative radiotherapy. One patient developed a local recurrence, no regional recurrences or distant metastases were observed. After a median follow-up of 49 months the 5- and 10-year overall survival were 95%, the 5- and 10-year disease free survival were 89%.

CONCLUSION

The clinical course of SC is favorable with a low rate of locoregional recurrence and excellent survival. Given the low incidence of nodal metastases, elective neck treatment, i.e. surgery and/or radiotherapy, does not seem to be indicated.

Characterisation of DOG-1 Expression in Salivary Gland Tumours and Comparison with Myoepithelial Markers

DOG1 is an established diagnostic marker for gastrointestinal stromal tumours (GIST), but has been reported in salivary gland tumours (SGT) as an acinar and intercalated duct marker. However, its specificity and distribution is not well established. The aim of this study was to evaluate the diagnostic utility of DOG-1 expression in SGT in addition to comparing it with myoepithelial markers. Normal salivary tissue and SGT (n = 184) were examined for expression of DOG1 and a range of myoepithelial markers. SGT included: acinic cell carcinoma (ACC, n = 15), secretory carcinoma (SC, n = 9), pleomorphic adenoma (PA, n = 49), carcinoma ex-PA (Ca ex-PA, n = 11), adenoid cystic carcinoma (AdCC, n = 20), polymorphous adenocarcinoma (PAC, n = 6), myoepithelioma (n = 6), myoepithelial carcinoma (MC, n = 2), basal cell adenoma (BCA, n = 14), canalicular adenoma (CA, n = 19), mucoepidermoid carcinoma (MEC, n = 11), oncocytoma (n = 2), adenocarcinoma NOS (AdNOS, n = 4), basal cell adenocarcinoma (BCAC, n = 2), salivary duct carcinoma (SDC, n = 3) and papillary cystadenocarcinoma (PCAC, n = 1). Normal acini and ACC (14/15) showed strong luminal DOG1 staining; SC were largely negative with only focal expression in 3/9 cases. Luminal staining was seen in PA (14/49), PAC (4/6), Ca ex-PA (4/11) and AdCC (6/20). 8/11 MEC showed luminal and/or mucous cell staining. No staining was seen in myoepithelioma, MC, CA, adNOS and BCAC. BCA showed strong staining of myoepithelial cells in some cases (5/14). Variable myoepithelial DOG1 staining was seen in PA, Ca ex PA, BCA, SDC and PCAC which was not as consistent as myoepithelial markers such as calponin, p63 and αSMA. Absence of DOG1 can differentiate ACC from SC, but staining is variable in PA, PLGA and Ca ex-PA. Myoepithelial staining in some tumours but not in normal gland suggests a wider distribution in SGT than originally envisaged.

Diagnostic Approaches for Salivary Gland Tumors with Secretory and Microcystic Features

Secretory carcinoma (SC) of the salivary gland is a new entity that shares the unique morphologic features and cytogenetic characteristics of the ETV6-NTRK3 fusion gene with its breast counterpart. Before identification of SC of the salivary gland, it was most frequently diagnosed as acinic cell carcinoma (AciCC). We retrospectively reviewed our own database of salivary gland tumors harboring microcystic and papillary architecture and/or secretory features that were originally diagnosed as AciCC. We selected nine cases of AciCC showing diffuse S-100 expression on immunohistochemistry (IHC). A recently diagnosed case of SC was included in the study as a reference sample. We performed IHC of S-100 and mammaglobin and ETV6 gene fluorescence in situ hybridization (FISH) in all cases. Seven cases were positive for both S-100 and mammaglobin, while five of the seven (71.4%) demonstrated ETV6 gene translocation by FISH. In the cases which did not co-express either S-100 or mammaglobin on IHC, ETV6 gene rearrangement was not shown on FISH. In conclusion, if a salivary gland tumor has morphologic features of SC with co-expression of S-100 and mammaglobin, ETV6 FISH can be performed to confirm the diagnosis of SC of the salivary gland.

Sinonasal Secretory Carcinoma of Salivary Gland with High Grade Transformation: A Case Report of this Under-Recognized Diagnostic Entity with Prognostic and Therapeutic Implications

Secretory carcinoma (SC) is a recently described salivary gland carcinoma with characteristic ETV6-NTRK3 fusion. In this case report, we described a SC of the maxillary sinus that underwent high grade transformation in a 61-year-old patient. The diagnosis was confirmed by the presence of ETV6 translocation. Within the sinonasal tract, SC is an important differential diagnosis especially of sinonasal adenocarcinoma, non-intestinal type (non-ITAC), as these two entities bears histologic and immunophenotypic similarity. Distinction between these two tumors can be challenging based on the morphology alone and may require additional immunohistochemical and molecular studies. It is important to recognize that SC can occur in the sinonasal tract as correctly diagnosing SC may be prognostic relevant and may provide new targeted therapeutic avenues for these patients.

Difficulty in the Cytodiagnosis of Mammary Analogue Secretory Carcinoma: Survey of 109 Cytologists with a Case Originating from a Minor Salivary Gland

BACKGROUND

Mammary analogue secretory carcinoma (MASC) of the salivary gland shows morphologic similarities and shares an immunophenotype and characteristic ETV6-NTRK3 translocation with secretory carcinoma of the breast. We present a buccal case of MASC along with a survey-based debate about its cytologic diagnosis by fine-needle aspiration (FNA).

CASE

FNA of the buccal nodule of a 58-year-old Japanese man was initially performed by 3 cytologists who gave different assessments of the Papanicolaou classification (i.e., class II, III, and V). To investigate the potential for discrepant diagnosis of MASC on a larger scale, we distributed a survey with questions about the cytological diagnosis of the present case to cytologists at other institutions. A total of 109 cytologists completed the survey, providing varying assessments of the Papanicolaou classification: class I/II (14%), class III (53%), and class IV/V (33%). Most of the respondents (72%) could not identify a particular tumor or disease. Even the respondents who identified a particular tumor suggested widely differing diagnoses, from a benign lesion to various malignant tumors. Only 2 respondents correctly identified MASC.

CONCLUSION

Our experience and the results of the survey suggest difficulty in the cytodiagnosis of MASC.

Salivary gland epithelial neoplasms in pediatric population: a single-institute experience with a focus on the histologic spectrum and clinical outcome

Salivary gland epithelial neoplasms are rare in children and adolescents, with only a handful of large series having been published. A retrospective study was conducted for 57 cases in patients 20 years or younger. The tumors were located in the parotid (n=36), submandibular gland (n=7), and minor salivary glands (n=14). Nineteen (33%) tumors were pleomorphic adenoma, whereas the remaining (67%) were malignant. The histologic types of carcinomas were mucoepidermoid carcinoma (MEC, n=19, 33%), acinic cell carcinoma (n=7, 12%), adenoid cystic carcinoma (n=6, 11%), secretory carcinoma (mammary analogue) (SC, n=4, 7%), and myoepithelial carcinoma (n=2, 4%). Ninety-three percent (13/14) of the minor and 58% (25/43) of the major salivary gland tumors were malignant. A 7-year-old girl (2%) with a high-grade MEC died from her disease because of uncontrollable locoregional recurrence. Seven patients (16%) developed recurrence including 2 distant metastases from adenoid cystic carcinoma and 6 locoregional recurrences (2 pleomorphic adenomas, 1 SC, 1 myoepithelial carcinoma, 1 adenoid cystic carcinoma, and 1 MEC). The following parameters were associated with decreased disease-free survival in malignant tumors: elevated mitotic index of >4/10 high-power fields (log-rank test, P<.001), and advanced American Joint Committee on Cancer pT (P=.029) and pN stage (P<.001). In conclusion, myoepithelial carcinoma and SC can occur in the pediatric population and should be considered in the differential diagnosis. Salivary gland malignancies in children appear to have better clinical outcome, associated with a 10-year recurrence-free survival rate of 74% and a 10-year disease-specific survival of 94%.