Kajava Classification: The Person and the Research.

The Kajava classification for ectopic breast tissue is still widely used, although it was published in 1915 in Finnish. This historical note sheds light on the person and research behind the classification. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .