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Polymorphous low-grade adenocarcinoma: an analysis of epidemiological studies and hints for pathologists

Vera Cavalcanti de Araujo*, Fabricio Passador-Santos, Cecilia Turssi, Andresa Borges Soares and Ney Soares de Araujo

Author affiliations

Department of Oral Pathology, Sao Leopoldo Mandic Institute and Research Center, Rua Jose Rocha Junqueira13 Ponte Preta, Campinas, SP, 13045-755, Brazil

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Citation and License

Diagnostic Pathology 2013, 8:6  doi:10.1186/1746-1596-8-6

Published: 15 January 2013



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.


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.


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


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.

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Polymorphous low-grade adenocarcinoma; Epidemiological review; Diagnosis hints