Historical Evolution of the Polymorphous Adenocarcinoma.

The 2017 World Health Organization Classification of Head and Neck Tumors introduced for the first time the diagnostic terminology "cribriform variant of polymorphous adenocarcinoma". This nomenclature attempts to reconciliate the ongoing taxonomical controversy related to cribriform adenocarcinoma of tongue. In order to better understand this classification conundrum, it is imperative for pathologist to comprehend the historical evolution of polymorphous adenocarcinoma formerly known as polymorphous "low grade" adenocarcinoma. This review highlights our understanding of these tumors since their origins.