A correct and timely diagnosis of acute appendicitis is very important in the medical practice since it could avoid complications such as perforation, abscess formation and peritonitis, and at the same time could reduce the negative appendectomy rate. It is for this reason that several diagnostic scores has been developed during the last few decades with various results. One of the first ones was the Alvarado Score (MANTRELS) developed in 1986 with the aim to reduce the useless appendectomies without increasing the risk of perforations.