Abstract
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.
Acknowledgments
We would like to sincerely thank the pathologists and pediatricians participating in this study. Danjing Yin performed fluorescence in situ hybridization enabling the confirmation of our diagnosis
Author contributions
Authors Meng Zhao, Si Wu, Xiuli Zhu, Yueping Liu had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Yueping Liu and Meng Zhao.
Acquisition, analysis, or interpretation of data: Si Wu and Xiuli Zhu.
Drafting of the manuscript: Meng Zhao.
Critical revision of the manuscript for important intellectual content: All Authors.
Disclosure statement
No potential conflict of interest was reported by the authors.