Computed Tomography (CT) Findings of a Diagnostic Dilemma: Atypically Located Acute Appendicitis

Acute appendicitis is an emergent surgically treated disease generally represented by right lower abdominal pain. The most common location of the appendix is descending intraperitoneal. However, it can also show atypical locations such as inguinal canal, femoral canal, subhepatic, retrocecal, intraperitoneal abdominal midline and left side in situs inversus or intestinal malrotation patients. Atypical location can lead to atypical clinical presentations. Ultrasonography is the first choice modality for imaging. However, it can be insufficient for demonstration of the appendix. Therefore, computed tomography (CT) is needed for further examination. We aim to review the CT findings of atypically located acute appendicitis with cases and remind the clinicians and radiologists the importance of the prompt diagnosis.

We presented five atypically-located appendix cases, including four with acute appendicitis that presented to our emergency department with acute abdominal pain. Two of the acute appendicitis cases had normal, the other two had elevated white blood cell count, but all of them had elevated CRP. Ultrasonography imaging was performed as a first-line imaging modality. Because of the inconclusive results of both clinical-laboratory findings and ultrasonography, CT imaging was performed. Abdominal CT demonstrated all of the atypically localised appendices successfully, which were left-sided in a malrotated patient, retrocecal, subhepatic, retrocecal ascending, intraperitoneal abdominal midline localised.

Atypically located acute appendicitis can show atypical presentation and result in misdiagnosis. If ultrasonograpgy is inconclusive, we suggest abdominal CT in such confusing, complicated cases, because misdiagnosis or delay in the right diagnosis can result in complications and increased morbidity and mortality rates.