Clinicopathologic and molecular characterization of mammary analogue secretory carcinoma of salivary gland origin

Non Indigenous Mammary Secretory Carcinoma of Parotid Gland - An Unusual Presentation

Mammary analog secretory carcinoma (MASC) is a relatively rare, low-grade tumor affecting the salivary glands. We report a 62-year-old female who was diagnosed with MASC of the left parotid gland and underwent left Total conservative parotidectomy with condylectomy and reconstruction with right anterolateral free flap and left facial nerve (frontal branch) reconstruction with a cable graft. As there is no standard treatment protocol developed for the management of MASC, this report focuses on the various management options that have been followed to date.

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.

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.

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

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

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

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

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.

Secretory Carcinoma in Children and Young Adults: A Case Series

Secretory carcinoma (SC), previously known as mammary analogue secretory carcinoma, is a rare salivary gland neoplasm that typically presents as a slow-growing painless lesion in the head and neck. SC occurs mainly in adults but has been described in children with the youngest reported patient diagnosed at five years of age. In children the gender distribution has been reported as female to male ratio of 1:1.2. SC is generally considered a low-grade malignancy with characteristic morphological features and immunological profile. SC also harbors ETV6-NTRK3 fusion (t(12;15)(p13:q25)). Surgical resection with or without lymph node dissection is the standard treatment, with generally favorable clinical outcomes. Here we present a single institution case series of six patients (ages 9-21) with SC and a review of the previously described pediatric cases. Our small series showed male predominance in pediatric patients with predominantly low-grade and stage tumors. All cases underwent complete surgical resections and when follow up is available there was no evidence of recurrences or metastases. To the best of our knowledge, this is the only SC case series comprised exclusively of pediatric and youth patients.

Frozen Section of Parotid Gland Tumours: The Head and Neck Pathologist as a Key Member of the Surgical Team

Introduction: The aim of this study was to evaluate the impact of subspecialised head and neck versus general surgical pathologists on the reliability of the histopathologic evaluation during intraoperative consultation. Materials and Methods: The medical records of all patients who underwent a parotidectomy with frozen section between 2006 and 2021 were retrospectively evaluated. The frozen section was evaluated for sensitivity, specificity, accuracy, and predictive value. Assessment by two groups of pathologists (subspecialised head and neck versus general surgical pathologists) was compared, and the nature or types of misdiagnoses compared with final diagnoses on paraffin sections were analysed for the two groups. Results: Our study sample was made up of 669 cases. The mean age of patients was 57.7 years (range: 10−94 years). Of these, 490 patients had a benign lesion (73.2%), whereas 179 patients had a malignant lesion (26.8%). Frozen section had an overall accuracy of 97.6%, sensitivity for malignancy was 91.1%, specificity was 100%, PPV was 100%, and the NPV was 96.8%. The exact histologic subtype in the group of malignant tumours was correctly identified in FS in 89.4% of cases. A comparison of head and neck pathologists versus general surgical pathologists revealed a highly statistically significant difference concerning both overall detection of malignancy (p < 0.001) as well as correct identification of the histologic subtype (p < 0.001). Conclusion: Involvement of subspecialised head and neck pathologists in the intraoperative consultation for salivary gland tumours results in a gain of 19.8% more sensitivity, underlining the importance of specialisation in salivary gland pathology for the optimisation of frozen section quality.

Recent Advances on Immunohistochemistry and Molecular Biology for the Diagnosis of Adnexal Sweat Gland Tumors

Simple Summary

Cutaneous sweat gland tumors form an extremely diverse and heterogeneous group of neoplasms that show histological differentiation to the sweat apparatus. Due to their rarity, wide diagnostic range, and significant morphological overlap between entities, their accurate diagnosis remains challenging for pathologists. Until recently, little was known about the molecular pathogenesis of adnexal tumors. Recent findings have revealed a wide range of gene fusions and other oncogenic factors that can be used for diagnostic purposes and, for some, can be detected by immunohistochemistry. Among other organs containing exocrine glands, such as salivary glands, breasts, and bronchi, most of these biomarkers have been reported in homologous neoplasms that share morphological features with their cutaneous counterparts. This review aims to describe these recent molecular and immunohistochemical biomarkers in the field of sweat gland tumors.

Abstract

Cutaneous sweat gland tumors are a subset of adnexal neoplasms that derive or differentiate into the sweat apparatus. Their great diversity, rarity, and complex terminology make their pathological diagnosis challenging. Recent findings have revealed a wide spectrum of oncogenic drivers, several of which are of diagnostic interest for pathologists. Most of these molecular alterations are represented by gene fusions, which are shared with other homologous neoplasms occurring in organs containing exocrine glands, such as salivary and breast glands, which show similarities to the sweat apparatus. This review aims to provide a synthesis of the most recent immunohistochemical and molecular markers used for the diagnosis of sweat gland tumors and to highlight their relationship with similar tumors in other organs. It will cover adenoid cystic carcinoma (NFIB, MYB, and MYBL1 fusion), cutaneous mixed tumor (PLAG1 fusion), cylindroma and spiradenoma and their carcinomas thereof (NF-κB activation through CYLD inactivation or ALKP1 hotspot mutation), hidradenoma and hidradenocarcinoma (MAML2 fusion), myoepithelioma (EWSR1 and FUS fusion), poroma and porocarcinoma (YAP1, MAML2, and NUTM1 fusion), secretory carcinoma (ETV6, NTRK3 fusion), tubular adenoma and syringo-cystadenoma papilliferum (HRAS and BRAF activating mutations). Sweat gland tumors for which there are no known molecular abnormalities will also be briefly discussed, as well as potential future developments.

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.

Prognostic factors in mammary analogue secretory carcinomas of the parotid gland: Systematic review and meta-analysis

Mammary analogue secretory carcinomas (MASCs) of the parotid gland are considered as low-grade malignancies with good clinical outcome but lacking data regarding prognostic factors. We performed meta-analysis assessing prognostic factors for disease-free survival (DFS) and overall survival (OS) in 256 patients with MASCs of the parotid gland. A total of 73 studies have met the inclusion criteria and 76.3% of patients were seen with T1 and T2 tumors and negative neck nodes. Lymph node metastasis (57.4%) and distant recurrences (46.2%) were particularly found in T4 tumors (p < 0.001). DFS at 5 and 10 years was 77.9% and 47.2% compared to 88.1% and 77.2% for OS at the same time points. Male sex, T3-T4 tumors, and recurrent disease represented independent worse prognosticators for survival outcome. Altogether, parotid gland MASCs show good long-term outcome, but T4 tumors behave significantly more aggressive and require extended treatment strategies along with close follow-ups.

Clinicopathological characteristics and outcomes of 23 patients with secretory carcinoma of major salivary glands

This retrospective study investigated the clinicopathological characteristics of secretory carcinoma of salivary glands (SCSG) in 23 patients with histopathologically confirmed SCSG between January 2010 and December 2020. In total, 13 males and 10 females (ratio, 1.3:1) aged 10 − 69 years (median, 45 years) were enrolled in this study; the average disease duration was 2.44 years (0.25–20 years). Twenty-one patients (91.3%) had SCSG in the parotid gland, and two (8.7%) in the submandibular gland. All patients had single nodules of diameters 0.8–4.8 cm (average 2.6 cm); five with lymph node metastases, and two with distant metastases. Immunohistochemically, tumors stained positive for S-100, mammaglobin, CK7, GATA3 and pan-Trk, and negative for DOG1, P63, and calponin, with Ki-67 positivity from 1 to 50%. ETV6 gene rearrangement was confirmed in 15 patients. All patients underwent oncological resection, four had radioactive particles implanted postoperatively, one received chemotherapy, and seven underwent chemoradiotherapy. Six patients had regional recurrences, two distant metastases, and one died before the last follow-up. SCSGs are typically indolent, with a low locoregional recurrence rate and excellent survival. Prognosis is correlated to clinical stage, pathological grade, and surgical procedures.

Practical immunohistochemistry in the classification of salivary gland neoplasms

Diagnosis of salivary gland neoplasms can be challenging for surgical pathologists due to low incidence of tumors as well as overlapping histologic features. On small biopsy, the most important information to be conveyed for clinical management is the distinction between a benign/low grade tumor and a high grade carcinoma. This review will discuss the differential diagnosis of salivary gland tumors based on four broad morphologic patterns: basaloid/tubular/cribriform, (micro)cystic/secretory/mucinous, solid-nested/clear-spindled, and oncocytic/oncocytoid. With the assistance of immunohistochemistry, demonstration of the number of cell types (mainly epithelial versus myoepithelial/basal) can further subclassify tumors within these morphologic categories. Additional tumor-specific immunomarkers are useful in some cases. Underlying tumor-specific genetic anomalies can be of value, however, immunohistochemical correlates are only available for some. When used judiciously, in the correct morphologic context, and with knowledge of their limitations, immunohistochemical stains can aid in differentiating tumors with similar morphology.

A systematic review of secretory carcinoma of the salivary gland: where are we?

OBJECTIVE

The aim of this systematic review was to describe the epidemiology, diagnostic criteria, differential diagnosis, treatment, prognostic factors, and treatment outcomes of secretory carcinoma.

STUDY DESIGN

A comprehensive search of Lilacs, PubMed, Science Direct, and Web of Science databases was conducted to identify all case reports, letter to the editor, and histopathologic reclassifications regarding salivary gland secretory carcinoma published in English, Spanish, French, and Portuguese.

RESULTS

The final analysis included 119 studies, which totaled 642 secretory carcinoma diagnoses, with 239 case reports and 403 diagnostic reclassifications, mostly in the United States. The age range was 5 to 87 years, and cases were predominantly in males (58.7%) and mostly affecting the parotid glands (73.7%). The disease usually presents as a slow-growing, painless mass. The main differential diagnosis is acinic cell carcinoma, and the tumor is usually treated with surgery. The prognosis is considered favorable, although there have been reports of local recurrences, distant metastases, and deaths.

CONCLUSIONS

It is important that clinicians become aware of this salivary gland neoplasm and report clinical data, clinical course, management and long-term follow-up. There is an urgent need to conduct more clinical trials, especially on tropomyosin receptor kinase (TRK) inhibitors and other potential target therapy modalities.

Parotid mammary analogue secretory carcinoma: A case report and review of literature

BACKGROUND

Mammary analogue secretory carcinoma (MASC) is a rare low-grade malignant salivary gland tumor. The morphological and immunohistochemical features of MASC closely resemble those of breast secretory carcinoma. The key characteristics of the lesion are a lack of pain and slow growth. There is no obvious specificity in the clinical manifestations and imaging features. The diagnosis of the disease mainly depends on the detection of the MASC-specific ETV6-NTRK3 fusion gene.

CASE SUMMARY

This report describes a rare case of a 32-year-old male patient who presented with a gradually growing lesion that was initially diagnosed as breast-like secretory carcinoma of the right parotid gland. Imaging and histological investigations were used to overcome the diagnostic difficulties. The lesion was managed with right parotidectomy, facial nerve preservation, biological patch implantation to restore the resulting defect, and postoperative radiotherapy. On postoperative follow-up, the patient reported a mild facial deformity with no complications, signs of facial paralysis, or Frey’s syndrome.

CONCLUSION

The imaging and histological diagnostic challenges for MASC are discussed.

High-grade salivary gland carcinoma with the ETV6-NTRK3 gene fusion: A case report and literature review of secretory carcinoma with high-grade transformation

Secretory carcinoma or mammary analog secretory carcinoma is an entity of salivary gland carcinoma that is characterized by the ETV6-NTRK3 gene fusion. Although it is generally considered to be a low-grade malignancy, some cases of secretory carcinoma with high-grade transformation (SCHG) have been reported. We herein describe a case of SCHG composed almost exclusively of the high-grade component. The patient presented with a growing mass in the buccal mucosa and underwent surgery. Tumor cells showing high-grade nuclear atypia were arranged in solid or cribriform nests with comedo-like necrosis. A differential diagnosis included high-grade salivary gland carcinoma, such as salivary duct carcinoma. Immunohistochemically, tumor cells were focally positive for S-100 and negative for mammaglobin and showed nuclear positivity for pan-Trk. A reverse transcription polymerase chain reaction assay showed that the tumor harbored the ETV6-NTRK3 gene fusion. A histological review of microscopic slides of the tumor did not reveal a typical secretory carcinoma component, except for a very focal area. We ultimately diagnosed this tumor as SCHG. This case underscores the importance of recognizing the histological spectrum of SCHG and the utility of pan-Trk immunohistochemistry to detect secretory carcinoma, which may be targeted by tyrosine kinase inhibitors.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Dedifferentiated secretory breast carcinoma with fibrosarcomatous features harboring an ETV6-NTRK3 fusion in both components

Secretory carcinomas are low-grade translocation-driven carcinomas occurring in patients over a wide age range. These tumors most frequently arise in the breast and salivary gland, but may occasionally arise at other anatomic sites, such as the skin, the thyroid gland or the upper or lower respiratory tract. In concert with their low-grade morphology, secretory carcinomas most often follow an indolent clinical course. However, rare cases have shown dedifferentiation (also known as high-grade transformation) and aggressive clinical behavior. To date, the dedifferentiated component in all molecularly confirmed cases of secretory carcinoma has taken the form of a high-grade carcinoma. Here we present a case of an ETV6-NTRK3 fusion-positive secretory carcinoma of the breast with sarcomatous dedifferentiation. The sarcomatous component showed an infantile or adult fibrosarcoma-like morphology including a herringbone fascicular pattern and a hemangiopericytic vascular pattern. By immunohistochemistry, the sarcomatous component showed focal CD34 immunoreactivity and loss of all of the markers expressed in the conventional secretory carcinoma component, including SOX10, S100, GATA-3, AE1/AE3 and E-cadherin. Fluorescence in situ hybridization analysis revealed that the sarcomatous component retained the ETV6-NTRK3 fusion, but also acquired homozygous deletion of CDKN2A. The tumor followed an aggressive clinical course and the patient eventually succumbed to her disease 14 months after diagnosis. The histomorphologic and molecular genetic features of this tumor are discussed, including its ability to mimic kinase-rearranged infantile or adult fibrosarcomas at extramammary sites and the theragnostic importance of its distinction from conventional metaplastic spindle cell carcinomas in the breast.

MUC4 is a valuable marker for distinguishing secretory carcinoma of the salivary glands from its mimics

AIMS

Secretory carcinoma (SC) (synonym: mammary analogue secretory carcinoma) is a low-grade salivary gland tumour that occurs in both major and minor salivary glands. SC is known for its wide morphological, architectural and immunohistochemical spectrum, which overlaps with those of several salivary gland neoplasms, including acinic cell carcinoma (AciCC) and intercalated duct-type intraductal carcinoma (IDC) in major salivary glands, and polymorphous adenocarcinoma (PAC) in minor salivary glands. These tumours share with SC some morphological features and SOX10 immunoreactivity; also, with the exception of AciCC, they all coexpress S100 and mammaglobin.

METHODS AND RESULTS

We compared MUC4 and mammaglobin expression in 125 salivary gland carcinomas (54 genetically confirmed SCs, 20 AciCCs, 21 PACs, and 30 IDCs) to evaluate the potential of these two markers to differentiate these entities. Moderate to strong diffuse MUC4 positivity was detected in 49 SCs (90.7%), as compared with none of the IDCs and PACs. In contrast, mammaglobin was frequently expressed in SCs (30 of 36 cases; 83.3%), IDCs (24/28; 85.7%), and PACs (7/19; 36.8%). Two of three high-grade SCs lost MUC4 expression in the high-grade tumour component. No significant correlation was found between MUC4 expression and the fusion variant in SC (ETV6-NTRK versus non-ETV6-NTRK).

CONCLUSION

The results of our study identify MUC4 as a sensitive (90.7%) and specific (100%) marker for SC, with high positive (100%) and negative (93.4%) predictive values. Thus, MUC4 may be used as a surrogate for SC in limited biopsy material and in cases with equivocal morphology.

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.

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.

Characterization of novel genetic alterations in salivary gland secretory carcinoma

Secretory carcinoma is a salivary gland tumor with a characteristic chromosomal translocation that results in an ETV6-NTRK3 fusion gene. Secretory carcinoma shows relatively frequent rates of lymph-node metastasis and tumor recurrence and has a characteristic histology. Except for the ETV6 translocation, genomic alterations in secretory carcinoma have not been reported. In the present study, we characterized the novel recurrent genetic mutations of secretory carcinoma. On the basis of histology, immunohistochemistry, and ETV6 gene break-apart fluorescence in situ hybridization assays, 22 tumors were classified as secretory carcinomas (19 ETV6 translocation-positive and 3 ETV6 translocation-negative secretory carcinomas) and their clinicopathologic characteristics were reviewed. Targeted deep sequencing analyses were performed on 20 secretory carcinomas (17 ETV6 translocation-positive and 3 ETV6 translocation-negative secretory carcinomas) to investigate their genetic alterations. The A16V (C→T) mutation in PRSS1, which encodes a cationic trypsinogen and has a mutation associated with hereditary pancreatitis and pancreatic adenocarcinoma, was observed in 40% (8/20) (7/17 of ETV6 translocation-positive and 1/3 of ETV6 translocation-negative secretory carcinomas). Pathogenic variants of MLH1, MUTYH, and STK11 were also identified. Variants of uncertain significance included mutations in KMT5A. These novel characteristic genetic alterations may advance current understandings of secretory carcinoma tumorigenesis and progression, leading to improved diagnoses and treatment strategies.

Primary Mammary-Like Carcinoma of the Lung: A Case Report of a Distinct Type of Primary Lung Carcinoma

A case of a primary lung carcinoma with histologic and immunohistochemical features of a mammary carcinoma is presented. The patient is a 72-year-old man who presented with symptoms of cough and dyspnea. Diagnostic imaging showed a bronchial tumor in the left lower lobe that was surgically resected by a left lower lobectomy. The tumor was characterized by a homogenous cellular proliferation composed of small to medium-sized cells with round nuclei and inconspicuous nucleoli. Multiple immunohistochemical stains were performed, and the tumor was notably positive for estrogen receptor, progesterone receptor, GATA3, and pan-keratin, while molecular analysis showed somatic mutation in ARID1A. Clinical follow-up showed that the patient is alive and well 18 months post-surgical resection without evidence of recurrence or metastatic disease. Based on the overall features of this neoplasm, we consider that the tumor herein presented represents an unusual type of lung carcinoma that we refer to as primary mammary-like carcinoma of the lung.

[Secretory carcinoma of the salivary gland (mammary analogue secretory carcinoma) in children]

Secretory carcinoma of the salivary gland is a tumor that was first described less than 10 years ago and that mainly occurs in the parotid salivary gland in the elderly. Analyzing the literature over 8 years since the first description of the tumor identifies the main clinical, morphological, and genetic signs of the diagnosis of secretory carcinoma with a focus on the pediatric population. Four new cases of secretory carcinoma of the salivary glands, which have been diagnosed in children of the youngest age encountered in the literature, are also described.

TRK Fusions Are Enriched in Cancers with Uncommon Histologies and the Absence of Canonical Driver Mutations

PURPOSE

TRK inhibitors achieve marked tumor-agnostic efficacy in TRK fusion-positive cancers and consequently are now an established standard of care. Little is known, however, about the demographics, outcomes, response to alternative standard therapies, or genomic characteristics of TRK fusion-positive cancers.

EXPERIMENTAL DESIGN

Utilizing a center-wide screening program involving more than 26,000 prospectively sequenced patients, genomic and clinical data from all cases with TRK fusions were extracted. An integrated analysis was performed of genomic, therapeutic, and phenomic outcomes.

RESULTS

We identified 76 cases with confirmed TRK fusions (0.28% overall prevalence) involving 48 unique rearrangements and 17 cancer types. The presence of a TRK fusion was associated with depletion of concurrent oncogenic drivers (P < 0.001) and lower tumor mutation burden (P < 0.001), with the exception of colorectal cancer where TRK fusions cooccur with microsatellite instability (MSI-H). Longitudinal profiling in a subset of patients indicated that TRK fusions were present in all sampled timepoints in 82% (14/17) of cases. Progression-free survival on first-line therapy, excluding TRK inhibitors, administered for advanced disease was 9.6 months [95% confidence interval (CI), 4.8-13.2]. The best overall response rate achieved with chemotherapy containing-regimens across all lines of therapy was 63% (95% CI, 41-81). Among 12 patients treated with checkpoint inhibitors, a patient with MSI-H colorectal cancer had the only observed response.

CONCLUSIONS

TRK fusion-positive cancers can respond to alternative standards of care, although efficacy of immunotherapy in the absence of other predictive biomarkers (MSI-H) appears limited. TRK fusions are present in tumors with simple genomes lacking in concurrent drivers that may partially explain the tumor-agnostic efficacy of TRK inhibitors.

Ancillary testing in salivary gland cytology: A practical guide

Salivary gland cytology is challenging, and historically the role of ancillary testing has been limited. However, numerous molecular/genetic advances in the understanding of salivary gland neoplasms during the last decade have facilitated the development of many useful diagnostic markers, such as PLAG1 and HMGA2 immunohistochemistry for pleomorphic adenoma and ETV6 fluorescence in situ hybridization for secretory carcinoma. Numerous salivary gland neoplasms are characterized by specific molecular/genetic alterations, many of which can be identified on cytologic preparations by karyotype analysis, fluorescence in situ hybridization, or immunohistochemical surrogates. Next-generation sequencing also has potential diagnostic applications, although to the authors' knowledge it currently has no routine role in salivary cytology. The primary goal of salivary fine-needle aspiration (FNA) is to facilitate appropriate clinical management. Ancillary testing has greatly enhanced the ability for accurate classification as per The Milan System for Reporting Salivary Gland Cytopathology and allows for the definitive diagnosis of many salivary FNA specimens, and also may resolve diagnostic uncertainty for FNAs that may be classified in The Milan System for Reporting Salivary Gland Cytopathology categories of salivary gland neoplasm of uncertain malignant potential or suspicious for malignancy. This review provides an updated discussion of the molecular/genetic features of the more commonly encountered salivary neoplasms by FNA, and discusses the application of available diagnostic immunohistochemical and molecular tests in salivary gland cytology.

The multifaceted role of TMEM16A in cancer

The calcium-activated chloride channel TMEM16A is intimately linked to cancers. Over decades, TMEM16A over-expression and contribution to prognosis have been widely studied for multiple cancers strengthening the idea that TMEM16A could be a valuable biomarker and a promising therapeutic target. Surprisingly, from the survey of the literature, it appears that TMEM16A has been involved in multiple cancer-related functions and a large number of molecular targets of TMEM16A have been proposed. Thus, TMEM16A appears to be an ion channel with a multifaceted role in cancers. In this review, we summarize the latest development regarding TMEM16A contribution to cancers. We will survey TMEM16A contribution in cancer prognosis, the origins of its over-expression in cancer cells, the multiple biological functions and molecular pathways regulated by TMEM16A. Then, we will consider the question regarding the molecular mechanism of TMEM16A in cancers and the possible basis for the multifaceted role of TMEM16A in cancers.

A Cribriform Cancer Metastatic to Liver: Case Report and Literature Review

Metastasis from salivary gland tumors to liver is exceedingly uncommon. Reported is the first case of a mammary analog secretory carcinoma (MASC) of salivary gland origin metastasized to the liver, even after complete surgical resection. A 76 year old female, with past history of a completely extirpated right parotid gland MASC, presented 2 years after right superficial parotidectomy and right neck dissection, with back and flank pain. Subsequent abdominal and pelvic CT revealed multiple small hepatic lesions. Biopsy of the largest hepatic lesion confirmed metastatic MASC of primary parotid gland origin. Both the parotid primary and the hepatic metastases had the confirmatory ETV6 rearrangement by fluorescence in situ hybridization. Although high-grade malignancy and distant metastases of MASC of salivary gland origin to liver is rare, recognizing metastatic MASC potentially alters prognosis and determines therapeutic options.

Mammary analogue secretory carcinoma presenting as a cystic parotid mass

We present a case of a 63-year-old male with an 8-year history of a left-sided cystic facial mass which recurred despite multiple drainage procedures. Imaging findings showed a cystic mass in the left parotid gland and it was surgically resected. Pathology confirmed it to represent a mammary analogue secretory carcinoma, a relatively newly described entity. This case illustrates that mammary analogue secretory carcinoma can masquerade as a cyst within the parotid gland.

Mesonephric adenocarcinoma of the cervix: a case report with a three-year follow-up, lung metastases, and next-generation sequencing analysis

Background

Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis.

Case presentation

The patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal. The patient underwent a total hysterectomy outside the institution. During biopsy, the mass showed a cerebroid aspect. Histological study revealed a tumor with a predominantly tubular and ductal growth pattern. The immunoprofile showed negative staining for calretinin, carcinoembryonic antigen (CEAm), estrogen receptors (ER), and progesterone receptors (PR), and positive staining for CD10, p16, and PAX2. The Ki-67 score was 46%. Using a next-generation sequencing assay, we documented genomic alterations in KRAS and CTNNB1, low tumor mutation burden (TMB), and an absence of microsatellite instability. In addition, gain of the long arm of chromosome 1 (1q) was also documented using chomogenic in situ hybridization (CISH). Three years later, the patient presented pulmonary nodules in the lingula and left basal lobe that were resected by thoracotomy. The histopathologic study of the pulmonary nodules confirmed the presence of metastases.

Conclusion

Carcinomas of mesonephric origin are among the rarest subtypes of cervical tumors. We report the first case of mesonephric adenocarcinoma of the cervix with lung metastases showing a CTNNB1 gene mutation.

Secretory Carcinoma of the Parotid: Making the Correct Diagnosis of a Rare Salivary Gland Carcinoma When Molecular Biology Testing Is Not Available

Secretory carcinoma (SC) is a recently described entity occurring in the salivary glands. Before its description, SC was frequently classified as acinic cell carcinoma (ACC) or adenocarcinoma, not otherwise specified. Its particular histopathological and immunohistochemical characteristics are reminiscent of breast secretory carcinoma. Moreover, it displays a characteristic t(12;15) (p13;q25) translocation that results in the ETV6-NTRK3 gene fusion. This translocation has not been reported in any other salivary gland carcinoma. Identification of the t(12;15) (p13;q25) translocation is the gold standard for diagnosis, although some cases that do not present this specific translocation have already been reported. In such cases, diagnosis is challenging. In addition, some diagnostic pathology laboratories lack the resources to perform the molecular analysis to diagnose SC. In this scenario, morphology and immunohistochemistry are fundamental. Therefore, we report a case emphasizing the typical morphology of SC and its immunochemical profile to establish a final diagnosis without molecular biology tests. This case aims to demonstrate the importance of recognizing the typical presentation of a rare tumor so that clinicians will be informed or reminded of it and consider this entity among the differential diagnoses, when necessary. Moreover, in low-resource settings where molecular analysis is not available, being familiar enough with the histology of this tumor and using the immunoprofile as a key tool for differential diagnosis would be of great importance in establishing the correct diagnosis. The differential diagnosis includes, above all, acinic cell carcinoma and other salivary neoplasms such as intraductal carcinoma, low-grade mucoepidermoid carcinoma, and adenocarcinoma, not otherwise specified, which is actually a rule-out diagnosis.

Secretory carcinoma of the major salivary gland: Provincial population-based analysis of clinical behavior and outcomes

BACKGROUND

Our aim was to identify the number of cases of secretory carcinoma (SC) of the major salivary gland in a population-based cohort and review its clinical behavior with long-term follow-up.

METHODS

All malignant salivary gland tumors (MSGTs) diagnosed between 1980 and 2014 were assessed for histological features compatible with SC and 140 were selected for further analysis.

RESULTS

Twenty two new cases of SC were identified, 19 of which were originally classified as acinic cell carcinoma, and 3 as adenocarcinoma, not otherwise specified (NOS). Lymph node involvement was less common in SC tumors (5%) than in the control group (11%). Disease recurrence was seen less frequently in SC (9%) than the control group (20%). Mean disease-free survival was 192 months for SC compared with 162 months for controls (P = 0.15).

CONCLUSION

The clinical course of SC is typically indolent with a low risk of relapse not significantly different from other low-grade MSGT.

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.

Salivary Secretory Carcinoma With a Novel ETV6-MET Fusion: Expanding the Molecular Spectrum of a Recently Described Entity

Secretory carcinoma of the salivary glands, also known as mammary analogue secretory carcinoma, is a recently described tumor characterized by generally indolent clinical behavior and recurrent ETV6-NTRK3 fusions. However, a small subset of recent cases with high-grade histology, aggressive behavior, or alternate molecular findings are expanding the spectrum of this entity. In this case, a 59-year-old female presented with an infiltrative submandibular gland tumor that was originally classified as a high-grade acinic cell carcinoma, papillary-cystic variant. She developed persistent local disease and, 11 years after initial presentation, was found to have widespread metastases. Rereview of her primary tumor highlighted microcystic, papillary, and solid architecture, eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli, abundant mitotic figures, and necrosis. Immunostains showed the tumor cells to be positive for S100 and mammaglobin and negative for DOG-1, and fluorescence in situ hybridization highlighted an ETV6 rearrangement, supporting a diagnosis of high-grade secretory carcinoma. Finally, next-generation sequencing demonstrated a novel ETV6-MET fusion. To our knowledge, this is the first ETV6-MET fusion reported in secretory carcinoma. This finding further expands the definition of secretory carcinoma while carrying implications for selecting appropriate targeted therapy.

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.

Synchronous Parotid (Mammary Analog) Secretory Carcinoma and Acinic Cell Carcinoma: Report of a Case

Mammary analogue secretory carcinoma (MASC) is a recently described low-grade salivary gland malignancy with histologic, immunohistochemical and molecular similarities to secretory carcinoma of the breast, including a specific t(12;15)(p13;q25) resulting in an ETV6-NTRK3 gene fusion. Ultrasound and magnetic resonance imaging frequently document a macrocystic structure. The main differential diagnosis of secretory carcinoma is with low grade acinic cell carcinoma (AciCC). The two can be differentiated with immunohistochemical stains for S100, mammaglobin, carbonic anhydrase VI and DOG-1; the identification of the specific translocation can help to characterize non-typical cases. We report a unique case of synchronous MASC and AciCC presenting in a parotid gland and discuss the implications of the correct identification of the two tumors.