Differential Diagnosis for Right Iliac Fossa Pain in Regards to Gynaecological Pathology

When considering right iliac fossa pain that might not be due to appendicitis, several gynaecological conditions should be taken into account. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis
  • Ectopic Pregnancy: This condition, where a fertilized egg implants outside the uterus, often presents with abdominal pain, which can be localized to the right iliac fossa if the ectopic pregnancy is located in the right fallopian tube. It's a critical diagnosis to consider due to its high morbidity and mortality if not promptly treated.
• Other Likely Diagnoses
  • Ovarian Cyst: Rupture or torsion of an ovarian cyst can cause severe pain in the lower abdomen, which may be localized to the right iliac fossa. The presentation can mimic appendicitis, making it a key differential.
  • Pelvic Inflammatory Disease (PID): PID involves infection of the female reproductive organs and can cause lower abdominal pain, which may be more pronounced on one side, including the right iliac fossa.
  • Mittelschmerz: This condition refers to mid-cycle pain associated with ovulation. While typically mild and short-lived, it can occasionally cause more significant discomfort that might be confused with other conditions.
• Do Not Miss Diagnoses
  • Ruptured Ovarian Cyst with Hemorrhage: Although somewhat rare, a ruptured ovarian cyst can lead to significant internal bleeding, which is a medical emergency. The initial presentation might be similar to other less severe conditions, making it crucial not to miss.
  • Ovarian Torsion: This is a gynaecological emergency where the ovary twists around its ligaments, cutting off its blood supply. It can present with sudden, severe abdominal pain and must be treated promptly to save the ovary.
• Rare Diagnoses
  • Endometriosis: While endometriosis is not rare, it less commonly presents as an acute abdomen or with focal pain in the right iliac fossa. However, it can cause chronic pelvic pain and should be considered in the differential for recurrent or persistent symptoms.
  • Paratubal Cyst: These are cysts that form near the fallopian tubes and can cause pain if they rupture or become twisted. They are less common than other ovarian cysts but should be considered in the differential diagnosis.

Each of these conditions has the potential to present with right iliac fossa pain and should be considered when evaluating a female patient with such symptoms, especially if appendicitis has been ruled out or is less likely. The clinical presentation, patient history, and diagnostic imaging play crucial roles in distinguishing between these conditions.