title: A pediatric case of mammary analogue secretory carcinoma within the parotid.
abstract: Mammary analogue secretory carcinoma (MASC) is a recently described entity in the differential diagnosis of salivary gland tumors. It is notable for a characteristic t(12;15)(p13;q25) translocation that results in a unique fusion protein, ETV6-NTRK3. While several studies have retrospectively identified this translocation in cases previously diagnosed as a different salivary malignancy, there have been relatively few cases where this translocation was identified on initial pathology results, and fewer still in a pediatric population. We present a case of a 15 year old female with a slowly enlarging, painless, left facial mass. MRI demonstrated a cystic mass extending into the deep lobe of the parotid, and she underwent parotidectomy. The tumor cells stained positive for S100 and CK19. ETV6 translocation was present, confirming the diagnosis. Mammary analogue secretory carcinoma is a recently described tumor of the salivary glands, which often masquerades as more common primary salivary gland tumors and cysts. More research is needed to characterize the typical behavior of this neoplasm and the optimal treatment regimen. With identification of its characteristic translocation, mammary analogue secretory carcinoma can be easily differentiated from its more prevalent counterparts, and should therefore remain within the differential of the pathologist and head and neck surgeon.
authors.affiliation: Department of Otolaryngology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO.
authors.forename: S Craig
authors.initials: SC
authors.lastname: Quattlebaum
authors.affiliation: Department of Otolaryngology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO.
authors.forename: Brianne
authors.initials: B
authors.lastname: Roby
authors.affiliation: Department of Pathology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Dishop
authors.affiliation: Department of Pathology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO.
authors.forename: M Sherif
authors.initials: MS
authors.lastname: Said
authors.affiliation: Department of Otolaryngology, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO. Electronic address: Kenny.Chan@childrenscolorado.org.
authors.forename: Kenny
authors.initials: K
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D000069295:Mammary Analogue Secretory Carcinoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D010307:Parotid Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014178:Translocation, Genetic; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D015514:Oncogene Proteins, Fusion; C484319:ETV6-NTRK3 fusion protein, human; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein