Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: August 17, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Differential Diagnosis for Right Iliac Fossa Mass

Single Most Likely Diagnosis

  • Appendicitis: This is often the first consideration for a right iliac fossa mass due to its common presentation with pain, tenderness, and sometimes a palpable mass in the right lower quadrant of the abdomen. The mass could be an inflamed appendix or an appendicular mass.

Other Likely Diagnoses

  • Cecal Diverticulitis: Similar to appendicitis, cecal diverticulitis can present with right lower quadrant pain and a mass if an abscess or significant inflammation is present.
  • Intestinal Obstruction: Although not always a direct cause of a mass, an obstruction can lead to significant bowel dilation, which might be palpable, especially if it involves the cecum or the terminal ileum.
  • Mesenteric Lymphadenitis: This condition, often seen in children and young adults, can mimic appendicitis and sometimes presents with a palpable mass in the right iliac fossa due to enlarged lymph nodes.
  • Right Ovarian Cyst or Torsion: In females, a large ovarian cyst or torsion can present as a mass in the right iliac fossa, accompanied by acute pain.

Do Not Miss Diagnoses

  • Ectopic Pregnancy: Although less common, an ectopic pregnancy can present with abdominal pain and a mass, and missing this diagnosis can be catastrophic.
  • Intussusception: More common in children but can occur in adults, intussusception is a condition where a part of the intestine telescopes into another, which can cause bowel obstruction and potentially a palpable mass.
  • Cancer (e.g., Carcinoid Tumor, Lymphoma): Various types of cancer can present with a mass in the right iliac fossa. While less common, these diagnoses are critical not to miss due to their significant implications for treatment and prognosis.

Rare Diagnoses

  • Right Iliac Fossa Hematoma: A collection of blood in the right iliac fossa, which could be due to trauma, anticoagulation, or other bleeding disorders.
  • Actinomycosis: A rare bacterial infection that can cause chronic inflammation and abscess formation, potentially presenting as a mass.
  • Hydatid Cyst: In endemic areas, a hydatid cyst of the liver or other abdominal organs can rupture and present as a mass in the right iliac fossa.
  • Retroperitoneal Fibrosis: A rare condition characterized by the proliferation of fibrous tissue in the retroperitoneum, which can encase and obstruct structures, potentially presenting with a palpable mass.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.