Endometriosis is found on the ovaries in most patients and is typically bilateral. Other common pelvic structures involved include the pouch of Douglas (particularly the uterosacral ligaments and rectovaginal septum), the round ligament, the fallopian tubes, and the sigmoid colon (Fig. 29.1 and Table 29.1). On rare occasions, distant endometriosis is found in abdominal surgical scars, the umbilicus, and various organs outside the pelvic cavity.
The gross appearance of endometriosis varies considerably and includes the following forms:
· Small (1-mm), clear or white lesions
· Small, dark red (“mulberry”) or brown (“powder burn”) lesions
· Cysts filled with dark-red or brown hemosiderin-laden fluid (“chocolate” cysts)
· Dark-red or blue “domes” that may reach 15–20 cm in size
Reactive fibrosis frequently surrounds these lesions, which gives a puckered appearance. More advanced disseminated disease causes further fibrosis and may result in dense adhesions.