title: Polymorphous low-grade adenocarcinoma: an analysis of epidemiological studies and hints for pathologists.
abstract: BACKGROUND
  This study is an analysis of the prevalence of polymorphous low grade adenocarcinoma (PLGA) in epidemiological surveys of salivary tumors published in the English language from 1992 to 2012.
  
  
  METHODS
  These surveys included studies from different researchers, countries and continents. The 57 surveys for which it was possible to calculate the percentage of PLGAs among all malignant minor salivary gland tumors (MMSGT) were included in this review.
  
  
  RESULTS
  The statistical analyses show significant differences in the PLGA percentage by time period, country and continent in the studies included in this review. The percentage of PLGAs among MMSGTs varied among the studies, ranging from 0.0% to 46.8%. PLGA rates have varied over the period studied and have most recently increased. The frequency of reported PLGA cases also varied from 0.0% to 24.8% by the country in which the MMSGT studies were performed. The PLGA percentages also varied significantly by continent, with frequencies ranging from 3.9% in Asia to 20.0% in Oceania
  
  
  CONCLUSIONS
  Based on these results, we concluded that although the accuracy of PLGA diagnoses has improved, they remain a challenge for pathologists. To facilitate PLGA diagnoses, we have therefore made some suggestions for pathologists regarding tumors composed of single-layer strands of cells that form all of the histological patterns present in the tumor, consistency of the cytological appearance and uniformly positive CK7, vimentin and S100 immunohistochemistry, which indicate a single PLGA phenotype.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1059098656858324.
authors: Department of Oral Pathology, Sao Leopoldo Mandic Institute and Research Center, Rua Jose Rocha Junqueira13 Ponte Preta, Campinas, SP, 13045-755, Brazil. vcaraujo@usp.br.
authors: Vera Cavalcanti
authors: VC
authors: de Araujo
authors: Fabricio
authors: F
authors: Passador-Santos
authors: Cecilia
authors: C
authors: Turssi
authors: Andresa Borges
authors: AB
authors: Soares
authors: Ney Soares
authors: NS
authors: de Araujo
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000453:epidemiology* / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D016021:Epidemiologic Studies; D006801:Humans; D007150:Immunohistochemistry; D060787:Neoplasm Grading; D010641:Phenotype; D011237:Predictive Value of Tests; D015995:Prevalence; D012111:Residence Characteristics; D012468:Salivary Gland Neoplasms / Q000737:chemistry / Q000453:epidemiology* / Q000473:pathology*; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor