Differential Diagnosis for 30-year-old Female with Right Lower Quadrant Abdominal Pain
- Single Most Likely Diagnosis
- Pelvic Inflammatory Disease (PID): The presence of prominent pelvic lymph nodes and possible pelvic congestion on CT, along with the patient's symptoms of right lower quadrant abdominal pain, suggests an inflammatory process. The normal appendix and bowel make other causes of abdominal pain less likely, pointing towards a gynecological origin such as PID.
- Other Likely Diagnoses
- Ovarian Cyst or Corpus Luteum Cyst: The incidental finding of a left ovarian follicle on CT and a dominant left ovarian follicle on transvaginal ultrasound could be related to the patient's pain, especially if there's a rupture or leakage, although the absence of torsion makes this less likely.
- Endometriosis: This condition can cause chronic pelvic pain and could be considered given the patient's age and symptoms, although it's more of a chronic condition and might not fully explain the acute presentation.
- Do Not Miss Diagnoses
- Ectopic Pregnancy: Although the patient's symptoms and imaging do not strongly suggest pregnancy, ectopic pregnancy is a life-threatening condition that must be ruled out in any female of childbearing age presenting with abdominal pain. The equivocal urinalysis (U/A) could be a hint towards considering a pregnancy test.
- Ovarian Torsion: Despite the ultrasound showing no evidence of torsion, this is a surgical emergency that can present with non-specific symptoms and must always be considered, especially with the presence of a dominant ovarian follicle.
- Appendicitis with Atypical Presentation: Although the CT shows a normal appendix, appendicitis can sometimes have an atypical presentation, especially in females, and should be considered due to its potential for serious complications if not treated promptly.
- Rare Diagnoses
- Adnexal Tumors: While less likely, tumors of the adnexa (such as ovarian or fallopian tube tumors) could present with pelvic pain and should be considered, especially if there are any abnormalities on imaging that suggest a mass.
- Pelvic Venous Congestion Syndrome: This condition involves chronic pelvic pain associated with ovarian and pelvic varices. It's a rare condition but could be considered given the mention of possible pelvic congestion on the CT scan.