Unexpected Histopathological Findings in Appendectomy Specimens: a Retrospective Study of 1627 Cases

Pathologic evaluation of the appendix after appendectomy is routine and can occasionally identify unexpected findings. The aim of the present study was to determine the incidence and type of pathologic diagnoses found in appendectomy specimens at our institution. The clinicopathological data of 1627 patients who underwent appendectomies for presumed acute appendicitis from January 2008 to October 2014 were reviewed retrospectively. There were 986 men and 641 women (sex ratio M/F = 1.5) aged between 16 months and 90 years (mean = 30 years). All patients underwent appendectomy (either open or laparoscopic). Histological examination of the surgical specimen showed acute inflammation of the appendix in 1455 cases (89.42 %), fibrosed appendix in 37 cases (2.27 %), and Enterobius vermicularis (n = 23). In 101 cases (6.2 %), the appendix was histologically normal. Incidental unexpected pathological diagnoses were noted in 57 appendectomy specimens. They included pinworm (n = 23), mucinous neoplasms (n = 12), neuroendocrine tumors (NET) (n = 8), adenocarcinoma (n = 2), granulomatous inflammation (n = 5), tuberculosis (n = 2), hyperplastic polyp (n = 1), tubular adenoma (n = 1), diverticulitis (n = 1), endometriosis (n = 1), and actinomycosis (n = 1). The routine histopathological examination of the appendix is of value for identifying unsuspected conditions requiring further postoperative management. Gross examination alone does not appear to be a good indicator of an unexpected finding on microscopic exam. It is recommended that in order to avoid misdiagnoses, all appendices should be histopathologically examined.