Question from a fellow primary care pathologist: about endometrial glandular cystic hyperplasia It should be noted that “endometrial glandular cystic hyperplasia” is a very old diagnostic term. In 1978, Tavassoli and Kraus proposed a 3-level classification: adenocystic hyperplasia, adenomatous hyperplasia, and atypical hyperplasia. Starting from the 2nd edition of WHO classification of female genital tumors in 1994, endometrial lesions were classified into 4 classes: simple hyperplasia, complex hyperplasia, simple atypical hyperplasia, and complex atypical hyperplasia. This 4-grade classification was still used in the 3rd edition of WHO in 2003. Although the 94th edition classified lesions into 4 categories, several studies found that the diagnostic compliance rate between pathologists was not high if the 4-category approach was followed, and when the first 2 items were combined and the last 2 items were combined, the compliance rate between pathologists was very high. In addition, for simple atypical hyperplasia, it was found in multiple case studies that the diagnostic conformity was very poor and the number of cases was very small, so many scholars doubted whether this type of lesion existed or not. Therefore, this year’s 4th edition of the WHO classifies endometrial glandular epithelial lesions into only two categories: hyperplasia without atypia and atypia/EIN, and the treatment options for both are clear: hyperplasia without atypia treated with hormones; atypia/EIN treated with hormones or hysterectomy; and endometrioid carcinoma treated with surgery. For patients with atypical hyperplasia/EIN, hormone therapy is suitable for young patients with fertility needs and can cure 90% of patients. In addition, patients with contraindications to surgery can also be treated with hormone therapy. Surgical treatment can both further clarify the diagnosis and cure pre-cancerous endometrial lesions and is indicated for most patients without contraindications to surgery, especially in remote areas where patients cannot receive regular check-ups.