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

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

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

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

OBJECTIVES

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

DATA SOURCES

Pubmed, Google Scholar, and Web of Science databases.

REVIEW METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1716-1724, 2024.

A Parotid Gland Mammary Analogue Secretory Carcinoma in a 4-Year-Old Boy: Case Report and Literature Review

Background: Mammary analogue secretory carcinoma (MASC) is characterized by similar histologic, immunohistochemical, and molecular features with breast secretory carcinoma. MASC usually occurs in adults. Case report: A 4-year-old boy presented with a right infra-auricular mass. Features of the tumor include solid, tubular, and papillary growth patterns, with homogenous eosinophilic secretions inside microcystic structures. Immunohistochemical stains showed strong, diffuse staining for CK7, S100, pan-TRK protein. P63 was positive in a peripheral pattern. Fluorescence in situ hybridization (FISH) analysis showed the characteristic ETV6-NTRK3 gene fusion. Conclusion: Typical histological, immunohistochemical, and molecular features are present in MASC occurring early in childhood.

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

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

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

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

Secretory Carcinoma of the Salivary Gland: A Rarity in Children

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

Secretory Carcinoma 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.

Salivary gland carcinoma in children and adolescents: The EXPeRT/PARTNER diagnosis and treatment recommendations

Salivary gland carcinomas (SGCs) are rare during childhood and adolescence. Consequently, no standardized recommendations for the diagnosis and therapeutic management of pediatric SGC are available, and pediatric oncologists and surgeons generally follow adult guidelines. Complete surgical resection with adequate margins constitutes the cornerstone of treatment. However, the indications and modalities of adjuvant therapy remain controversial and may be challenging in view of the potential long-term toxicities in the pediatric population. This paper presents the consensus recommendations for the diagnosis and treatment of children and adolescents with SGCs, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded PARTNER project (Paediatric Rare Tumours Network - European Registry).