Differential Diagnosis for Chronic RLQ Pain in a Patient with History of Endometriosis

• Single most likely diagnosis:
  • Endometriosis recurrence or residual disease: Given the patient's history of endometriosis, multiple prior surgeries, and the presence of a Mirena IUD which can sometimes be associated with continued or recurrent symptoms in the setting of endometriosis, this diagnosis is highly plausible. The chronic nature of the pain and its location in the right lower quadrant (RLQ) also support this possibility, especially considering the history of a large endometrioma in the right ovary.
• Other Likely diagnoses:
  • Adhesions or bowel obstruction: The patient's history of multiple surgeries increases the risk of adhesions, which can cause chronic pain, bowel obstruction, or both. The RLQ pain could be related to adhesions involving the bowel or other structures in the pelvis.
  • Ovarian remnant syndrome: Although less common, the history of surgical removal of an endometrioma and the presence of chronic pain could suggest ovarian remnant syndrome, where residual ovarian tissue continues to produce hormones and cause pain.
  • Chronic pelvic inflammatory disease (PID): Despite the patient's current amenorrhea due to the Mirena IUD, a history of endometriosis and surgeries could predispose to PID, especially if there were any complications or infections post-surgery.
• Do Not Miss diagnoses:
  • Ovarian torsion: Although the patient has a history of a torsed and necrotic right ovary, the possibility of torsion of any remaining ovarian tissue or the left ovary cannot be overlooked, as it is a surgical emergency.
  • Ectopic pregnancy: Despite the Mirena IUD, which has a high efficacy for preventing pregnancy, the possibility of an ectopic pregnancy, although rare, is a "do not miss" diagnosis due to its potential for severe morbidity and mortality.
  • Appendicitis: Acute appendicitis can present with RLQ pain and must be considered, even in patients with a history of chronic pain, as it requires urgent surgical intervention.
• Rare diagnoses:
  • Malpositioned or perforated IUD: Although rare, a Mirena IUD could potentially cause chronic pain if it is malpositioned or has perforated the uterus, especially if it has migrated to the RLQ area.
  • Gastrointestinal disorders (e.g., Crohn's disease, ulcerative colitis): These conditions can cause chronic abdominal pain and should be considered, especially if there are other symptoms such as changes in bowel habits or weight loss.