Epidemiology and histopathological spectrum of appendiceal pathologies in 40.286 adults: a multicenter study from...

Acute appendicitis is one of the most common causes of emergency abdominal surgery, and routine histopathological examination of appendectomy specimens is critical for the detection of incidental neoplasms and non-neoplastic lesions. There is no large-scale, multicenter study on this subject in our country. This study aims to analyze the frequency, distribution, and clinico-demographic relationships of histopathological findings in appendectomy specimens.

This multicentre retrospective study analysed adult appendectomy cases from fifteen Turkish hospitals (2017-2025). Histopathology was classified into five categories, and demographic patterns and temporal trends were evaluated. The primary outcome was the distribution of appendiceal pathologies, with emphasis on the incidence of incidental neoplasms.

The study included a total of 40,286 adult patients. The average age was 36.01 ± 14.87 years, with 40.2% of patients being female (n = 16,186) and 59.8% being male (n = 24,100). Histopathological distribution: appendicitis 86.7% (n = 34,910, 74.8% uncomplicated, 11.4% complicated), no significant findings 4.8%, non-neoplastic lesions 6.8%, neoplasia 1.7%, other rare findings 0.1%. The neoplasia rate increased significantly with age (Spearman rho = 1.00, p < 0.001); it was 0.8% in the 20s and reached 14% in those aged ≥ 80. Mucinous neoplasms (0.7%) were the most common neoplastic lesions, followed by neuroendocrine tumors (0.5%). Neoplasia was more common in women (2.0%) than in men (1.4%) (p < 0.001).

This study is the largest series of appendectomies in Turkey and demonstrates that histopathological examination is indispensable in the detection of incidental neoplasms, especially in elderly patients. These findings support routine histopathological examination and suggest heightened neoplasm awareness, particularly in elderly patients.