Clinical meaning
The PALM-COEIN classification system, developed by FIGO (International Federation of Gynecology and Obstetrics), provides a standardized framework for categorizing causes of abnormal uterine bleeding in non-pregnant reproductive-age women. The acronym divides etiologies into structural causes (PALM) identifiable by imaging and histopathology, and non-structural causes (COEIN) that require clinical and laboratory evaluation. PALM categories include: Polyp (endometrial or endocervical polyps are localized overgrowths of endometrial tissue with a vascular stalk; most are benign but can harbor hyperplasia or carcinoma, especially in postmenopausal women); Adenomyosis (ectopic endometrial glands and stroma within the myometrium causing a diffusely enlarged, boggy uterus with dysmenorrhea and menorrhagia; the ectopic endometrial tissue responds to cyclic hormones, causing local inflammation, smooth muscle hyperplasia, and neoangiogenesis); Leiomyoma (uterine fibroids classified by FIGO as submucosal types 0-2 which directly distort the endometrial cavity and cause heavy bleeding, intramural types 3-5, and subserosal types 6-7 which rarely cause AUB); and Malignancy/hyperplasia (endometrial hyperplasia exists on a spectrum from simple hyperplasia without atypia with low malignant potential to complex atypical hyperplasia with 25-30% progression to endometrial carcinoma). COEIN categories include: Coagulopathy (inherited...