ABSTRACT
<p><b>OBJECTIVE</b>To analyze the relationship between hemomyelogram and sererity of acute appendicitis and identify the best routine blood test feature for perforation.</p><p><b>METHODS</b>721 patients were included in this study, all of whom underwent appendectomy for the clinical diagnosis of appendicitis during the years of 2010-2013. The initial preoperative hemomyelogram was evaluated at different stages of appendicitis. The area under the ROC curve was used to assess the clinical feature with greater diagnostic accuracy of perforation. Total lymphocyte counts of 1.83 was used in the prediction of perforative appendicitis. A group of 467 patients was used for validation to confirm the diagnostic value of the cut-off value.</p><p><b>RESULTS</b>The percentage of lymphocytes had the closest association with the evolutionary phase of acute appendicitis. Total lymphocyte counts < or=1.83 indicated perforation, with high sensitivity and low specificity.</p><p><b>CONCLUSION</b>The percentage of lymphocytes and total lymphocyte counts are helpful as a diagnostic paramete for different stages of acute appendicitis.</p>