Gynaecology & Obstetrics Endometriosis e5317a16 The organ NOT involved by endometriosis: A Liver B Lymph nodes C Brain D Spleen High-Yield Explanation Ans. is d, i.e. SpleenRef: Williams Gynecology, 3/ed, p23One pathological review revealed that endometriosis has been identified in all organs except spleen.