Pain in the right lower abdomen. Slightly raised infection parameters
In the first case only the proximal part of the appendix was visualized in the first examinations. The inflamed tip was initially missed leading to a small perirenal effusion and an effusion at the lowerpole of the liver. A retrocecal appendix can be difficult to examine with ultrasound becuse of overlying bowel gas. When it is very long, a focal abnormality can easily be missed.
The second case illustrates that a focal thickening of the appendix doesn't always mean that there is an appendicitis. Although the rounded shape of the tip and the vasculatity were suspicious for inflammation, in this case it was still fysiological. The diameter was still within normal limits and there were no secundary signs of inflammation
References
Optimizing US examination to detect the normal and abnormal appendix in children.
Peletti AB, Baldisserotto M.
Pediatr Radiol. 2006 Nov;36(11):1171-6.
US features of the normal appendix and surrounding area in children.
Wiersma F, Srámek A, Holscher HC.
Radiology. 2005 Jun;235(3):1018-22.