<prompt> The sites of endometriosis order of frequency are-Umbilicus, vulva, rectovaginal septumpelvic peritoneum, ovaries, laparotomy scarVagina, appendix, uterine ligamentsOvaries, uterine ligaments, rectovaginal septum  <response>: 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 