Appendectomy in familial Mediterranean fever : clinical, genetic and pathological findings

Abdominal attacks of familial Mediterranean fever (FMF) may simulate acute appendicitis and bring about considerable uncertainty. The similar presentation of the two clinical entities often leads to an unnecessary appendectomy. 182 consecutive FMF patients were retrospectively reviewed for this study. Clinical and genetic data was compared between those who had undergone an appendectomy (n=71) and those who had not (n=111). The frequency of appendectomy found in FMF was far above the reported rate in the general population (40% vs. 12-25%). The rate of non-inflamed appendectomies was extremely high (80% vs. 20%) and remained constant over time. Tertiary hospitals and improved therapeutic and diagnostic measures that have evolved over the years did not reduce misdiagnosis of acute appendicitis in FMF. Severe phenotype and homozygosity for M694V were identified as risk factors for appendectomy in FMF. A change from the regular diffuse involvement to right lower quadrant abdominal pain was found to be the best predictor of inflamed appendix in FMF patients undergoing appendectomy for suspected acute appendicitis. Reliance on clinical parameters should improve diagnostic accuracy of acute appendicitis in the FMF patient population.