Mucosal appendicitis: How can it be differentiated from nonappendicitis?

Abstract Objectives Mucosal appendicitis is defined by neutrophilic infiltration limited to the mucosa, with no transmural invasion; it is currently a controversial entity. The aim of our study was to determine whether mucosal appendicitis represents an early stage of acute appendicitis (AA) or should be considered a negative appendectomy. Methods A retrospective study was performed of children with suspected AA who underwent surgical treatment between 2017 and 2020. The participants were divided into 2 groups according to histologic appendiceal findings: mucosal appendicitis (MA) and negative appendicitis (NA). Demographic, clinical, ultrasound, and laboratory features were compared between the groups. Results A total of 1269 patients with suspected appendicitis in whom appendectomy was performed were included, with a median age of 10.5 years. Mucosal appendiceal inflammation was histologically confirmed in 30 cases (MA group), while no inflammation or other pathologic findings were observed in 25 cases (NA group), with no differences in demographic, clinical, or ultrasound features between the groups. Those in the MA group presented with significantly higher leukocyte and neutrophil counts and higher neutrophil to lymphocyte ratios (NLRs) than those in the NA group (P