Aim: The aim of this prospective nonrandomized study was to assess the necessity of interval 
appendectomy (IA) after successful conservative treatment of appendiceal mass.
Methods: A total of 69 patients with appendiceal mass (phlegmon or abscess) who received conservative 
treatment were included prospectively in the study. Failure of resolution occurred in 3 patients. The 
remaining patients (n =66) were followed up at the outpatient clinic and were nonrandomly assigned into 2 
groups according to the treatment modality selected by patients. 
Results: Four patients were lost to follow and one patient revealed cancer colon on colonic evaluation. 
Group I included 10 (16.4%) patients who underwent IA before a recurrence of appendicitis. Group II 
included 51 (83.6%) patients who underwent follow up without IA for 2 years. The rate of recurrent 
appendicitis was 17.6% (9/51). Of these recurrences, 7 (77.8%) occurred in the first 6 months. 
Conclusion: IA may be considered in selected patients after resolution of appendiceal mass. Otherwise, 
asymptomatic patients can be followed up without IA until appendicitis recurs since the recurrence rate is 
low and most of the recurrences occur with the first 3 to 6 months; therefore, many of the early recurrences 
may not be prevented by IA.