هیپرپلازی آندومتر تا قبل از سال 2014 بر اساس شکل غدد به دو دسته simple و complex و بر اساس ظاهر سلولها از نظر تغییرات شبه بدخیمی به دو دسته atypical و non-atypical تقسیم میشدند و در نهایت ما چهار نوع هیپرپلازی داشتیم:

simple nonatypical

simple atypical

complex nonatypical

complex atypical

بعدا مشاهده شد که شکل غدد در پروگنوز و درمان تاثیر آنچنان زیادی ندارد و توافق بین پاتولوژیستها برای تعیین حد مشخص بین simple / complex وجود نداشت لذا از سال 2014  WHO اصطلاحات فوق را حذف  و هیپرپلازی آندومتر را صرفا بر اساس ظاهر سلولها به دو دسته زیر تقسیم نمود:

  • benign (nonatypical) hyperplasia 
  • atypical hyperplasia (equivalent to endometrial intraepithelial neoplasia / EIN)

  • Prior to 2014, the World Health Organization classified endometrial hyperplasia as simple versus complex, and nonatypical versus atypical
    • This system suffered from significant interobserver variation (Am J Surg Pathol 2008;32:691)
    • Reproducibility improved with a two tier classification (Histopathology 2014;64:284, Int J Gynecol Pathol 2008;27:318)
    • Accordingly, the classification system was simplified in 2014, and now divides hyperplasia into two categories, benign (nonatypical) hyperplasia and atypical hyperplasia (equivalent to endometrial intraepithelial neoplasia / EIN)
  • The terms “simple” and “complex” have been removed from the classification; they, however, remain in parts of the following text when citing data prior to the 2014 WHO classification

  • Non atypical hyperplasia is part of the spectrum of endometrial changes due to unopposed estrogen stimulation
  • Incidence: 142 per 100,000 woman-years, peaks in early 50s (Am J Obstet Gynecol 2009;200:678)
  • 2 – 4x risk of progression to endometrial carcinoma compared to general population (compared to 45x for atypical hyperplasia / EIN) (Cancer 2005;103:2304)
  • < 1% prevalence of carcinoma diagnosis beyond 1 year after diagnosis of benign endometrial hyperplasia (Mod Pathol 2005;18:324, Hum Pathol 2008;39:866)