The sites of endometriosis order of frequency are-
It frequently is multifocal and often involves pelvic structures (ovaries, pouch of Douglas, uterine ligaments, tubes, and rectovaginal septum). Less frequently, distant areas of the peritoneal cavity or periumbilical tissues are involved. Uncommonly, distant sites such as lymph nodes, lungs, and even hea, skeletal muscle, or bone are affected. ref : Robbins Basic Pathology, 9E,page-689
Umbilicus, vulva, rectovaginal septum
pelvic peritoneum, ovaries, laparotomy scar
Vagina, appendix, uterine ligaments
Ovaries, uterine ligaments, rectovaginal septum
Breast