title: Mammary analog secretory carcinoma of salivary gland with high-grade histology arising in hard palate, report of a case and review of literature.
abstract: Mammary gland analog secretary carcinoma (MASC) of salivary gland is typically a tumor of low histologic grade and behaves as a low-grade malignancy with relatively benign course. This tumor shares histologic features, immunohistochemical profile, and a highly specific genetic translocation, ETV6-NTRK3, with secretory carcinoma of breast. Histologically, it is often mistaken as acinic cell carcinoma, adenocarcinoma not otherwise specified, and other primary salivary gland tumors. Here we report a case of MASC with high-grade transformation and cervical lymph node metastases confirmed with ETV6-NTRK3 translocation arising in the hard palate of a 41 year-old adult. Interestingly, the metastatic carcinoma has lower grade than the original tumor which strongly support malignant transformation of the original tumor. Most commonly, MASC arises from the parotid gland and less often in minor salivary glands. Metastasis is relatively uncommon and high-grade histology has only been reported in four cases with three of them arising from the parotid gland and the location of the fourth one has not been reported. This is the first case with high grade histology that arise from minor salivary gland and it emphasizes the importance of molecular screening of salivary gland tumor with high-grade histology for ETV6-NTRK3 translocation. In our literature of 115 cases that includes the current case, MASC occurred predominantly in adult with only a few cases under 18 years of age and a male to female ratio of 1.2:1. Parotid gland is more commonly affected but there is also significant occurrence in minor salivary glands. Except for the cases with high grade histology, the overall prognosis is good.
authors: Department of Pathology, University of Oklahoma Health Sciences Center OK 73104, USA.
authors: Wenyi
authors: W
authors: Luo
authors: Department of Pathology, University of Oklahoma Health Sciences Center OK 73104, USA.
authors: Sarah W
authors: SW
authors: Lindley
authors: Department of Radiology, University of Oklahoma Health Sciences Center OK 73104, USA.
authors: Peter H
authors: PH
authors: Lindley
authors: Department of Otorhinolaryngology, University of Oklahoma Health Sciences Center OK 73104, USA.
authors: Gregory A
authors: GA
authors: Krempl
authors: Department of Pathology, University of Pittsburgh Health System USA.
authors: Raja R
authors: RR
authors: Seethala
authors: Department of Pathology, University of Oklahoma Health Sciences Center OK 73104, USA.
authors: Kar-Ming
authors: KM
authors: Fung
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001706:Biopsy; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D002277:Carcinoma / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D016371:Cranial Irradiation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D060787:Neoplasm Grading; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D010157:Palatal Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D021362:Palate, Hard / Q000737:chemistry / Q000473:pathology* / Q000528:radiation effects / Q000601:surgery; D018714:Radiotherapy, Adjuvant; D011995:Recombination, Genetic; D012468:Salivary Gland Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; C484319:ETV6-NTRK3 fusion protein, human; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein
keywords: Analog secretary carcinoma; high grade; immunohistochemistry; salivary gland