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

Abstract

SummaryBackgroundAcute 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.Case ReportWe 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.ConclusıonsAtypically 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.

A pictorial essay of the most atypical variants of the vermiform appendix position in computed tomography with their possible clinical implications

“…Symptoms like fever, vomiting, and elevated inflammation laboratory markers are usually observed subsequently to the pain [5]. In cases of atypically located tip of the appendix the pain is localised in areas of the abdomen typical for other diseases and leads to a clinical dilemma [3,4,8,14,15]. A possible misdiagnosis may lead to complications including perforation, abscess, and peritonitis [3,7,16].…”

“…Ultrasound is usually the first-line imaging method in evaluation of patients with acute abdominal pain to confirm or exclude different conditions like cholecystitis and renal colic with hydronephrosis. However, it often may be helpful in establishing diagnosis of acute appendicitis, particularly in the typical pelvic position in the right iliac fossa, especially in children and during pregnancy [13,15,17]. It should be stressed that using ultrasound first instead of CT allows unnecessary exposure to radiation and iodine-based contrast media to be avoided [17,18].…”

Akutes Abdomen

“…B. Patienten mit Morbus Crohn im aktiven Schub, die zuerst medikamentös behandelt werden müssen, oder Patienten mit gynäkologischen Ursachen [33]. Des Weiteren ist die anatomische Lage entscheidend, denn gerade bei adipösen Patienten kann oft eine hoch retrozökal gelegene Appendixnichtodernurschwierig über den Wechselschnitt im rechten Unterbauch erreicht werden [34]. Nachdem sehr viele Appendektomien mittlerweile minimal-invasiv durchgeführt werden, kann die Lage der Appendix dem Chirurgen die Platzierung der Ports und das operative Konzept erleichtern [35], ein besonders bei adipösen Patienten deutlicher Vorteil [34].…”

“…Des Weiteren ist die anatomische Lage entscheidend, denn gerade bei adipösen Patienten kann oft eine hoch retrozökal gelegene Appendixnichtodernurschwierig über den Wechselschnitt im rechten Unterbauch erreicht werden [34]. Nachdem sehr viele Appendektomien mittlerweile minimal-invasiv durchgeführt werden, kann die Lage der Appendix dem Chirurgen die Platzierung der Ports und das operative Konzept erleichtern [35], ein besonders bei adipösen Patienten deutlicher Vorteil [34]. Im Fall der übergange-nen Appendizitis oder auch bei der akut perforierten Appendizitis, die sich nun mit intraabdominellem Abszess präsentiert, kann in vielen Fällen eine vorherige radiologisch-gezielte Drainage und Antibiose das Konzept der Wahl sein [36].…”

Acute epiploic appendagitis: ultrasound and computed tomography findings of a rare case of acute abdominal pain and the role of other imaging techniques

“…Clinically, EA manifests in most cases (60-80%) with acute or subacute abdominal pain in the left lower quadrant, but it can also involve the right lower quadrant, thus miming other diseases such as appendicitis, diverticulitis, acute cholecystitis, and omental infarction [12,23,24]. However, most patients have a normal body temperature, and laboratory results generally show a normal white blood cell (WBC) count [12,25]. In fewer cases, patients also complain of diarrhoea and constipation [23].…”