Citation, DOI & article data
Presentation of an inflamed subhepatic appendix is exceedingly uncommon, representing only 0.08% of all cases of appendicitis 1.
Appendicitis located in the RUQ often presents atypically compared to classical appendicitis. Cases of subhepatic appendicitis can present with pain in the RUQ and epigastric region in sharp contrast to the RLQ pain typically seen in a more commonly placed appendicitis 2. The unusual presentation can mimic pathology of gastric or hepatobiliary origin.
During normal development of the gastrointestinal tract, the primitive gut undergoes rotation resulting in the appendix entering the subhepatic region before descending as the colon elongates 2. The appendix completely enters the RLQ roughly by 4 months of age 3. Malrotation of the gut results in the appendix remaining in a subhepatic position thus leading to an appendicitis located in the upper abdomen should it become inflamed.
On ultrasound, a subhepatic position of the appendix may demonstrate dilated loops of ileum in the right lower abdomen with a vermiform structure present in the right upper abdomen 2.
CT will demonstrate mural thickening and enhancement of the appendix within the right hypogastrium. There may also be fluid collecting within the right paracolic gutter and subhepatic space 4.
History and etymology
Subhepatic appendicitis was first reported in 1863 3.
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