title: Mammaglobin and DOG-1 expression in polymorphous low-grade adenocarcinoma: an appraisal of its origin and morphology.
abstract: BACKGROUND
  Polymorphous low-grade adenocarcinoma (PLGA) remains a diagnostic challenge for most pathologists due to its large spectrum of histological patterns. In this study, the expression of two new markers recently described for salivary gland tumors was studied in PLGA.
  
  
  METHODS
  The morphology of 33 cases of PLGA was carefully evaluated using hematoxylin-and-eosin-stained sections and confirmed by immunohistochemistry for cytokeratin 7, vimentin, and S-100. Periodic acid-Schiff with diastase digestion was also used. The expression of mammaglobin and DOG-1 was carried out using the EnVision System. Mammaglobin was assessed according to the percentage of positively stained tumor cells, while DOG-1 was evaluated according to its presence and site. For MCM-2 and Ki-67, markers of proliferation, the labeling index of cell nuclei positivity was evaluated using total cell number. The ETV6-NTRK3 fusion was examined by fluorescence in situ hybridization analysis.
  
  
  RESULTS
  The histological patterns of the tumor were classified as lobular or non-lobular. For the non-lobular pattern, tubular, cribriform, glomeruliform, trabecular, and papillary patterns were observed. Mammaglobin was present in all PLGA cases, and its expression was stronger (P = 0.01) in the lobular than in the non-lobular pattern. The expression of DOG-1 was present in the apical portion and cytoplasm of the cells. Proliferation markers were low for all cases independent of histological pattern.
  
  
  CONCLUSIONS
  Polymorphous low-grade adenocarcinoma has been confirmed to originate from the intercalated duct and to feature high expression of mammaglobin in its lobular pattern resembling that of mammary secretory analogue carcinoma, except for the ETV6 gene rearrangement.
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Victor Angelo Martins
authors: VA
authors: Montalli
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Fabricio
authors: F
authors: Passador-Santos
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Elizabeth Ferreira
authors: EF
authors: Martinez
authors: Department of Oral Pathology, State University of São Paulo, Araçatuba, SP, Brazil.
authors: Cristiane
authors: C
authors: Furuse
authors: Department of Oral Pathology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
authors: Maria Cássia
authors: MC
authors: Aguiar
authors: Department of Anatomic Pathology, A.C. Camargo Cancer Center, São Paulo, Brazil.
authors: Fernando Augusto
authors: FA
authors: Soares
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Andresa Borges
authors: AB
authors: Soares
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Amy Louise
authors: AL
authors: Brown
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Ney Soares
authors: NS
authors: de Araújo
authors: Department of Oral Pathology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
authors: Vera Cavalcanti
authors: VC
authors: de Araújo
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000075369:Anoctamin-1 / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D060785:Mammaglobin A / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D012468:Salivary Gland Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: C476213:ANO1 protein, human; D000075369:Anoctamin-1; D014408:Biomarkers, Tumor; D060785:Mammaglobin A; D009363:Neoplasm Proteins
keywords: DOG-1; mammaglobin; morphology; origin; polymorphous low-grade adenocarcinoma