Published online Jul 7, 2013. doi: 10.3748/wjg.v19.i25.4015
Revised: May 1, 2013
Accepted: May 9, 2013
Published online: July 7, 2013
AIM: To investigate the prevalence and implications of unusual histopathological findings in appendectomy specimens from patients with suspected acute appendicitis.
METHODS: The demographic and histopathological data of 1621 patients (≥ 16 years-old) who underwent appendectomy to treat an initial diagnosis of acute appendicitis between January 1999 and November 2011 were retrospectively assessed. Microscopic findings were used to classify the patients under six categories: appendix vermiformis, phlegmonous appendicitis, gangrenous appendicitis, perforated appendicitis, supurative appendicitis, and unusual histopathologic findings. The demographic and clinicopathologic characteristics of patients with unusual histopathologic findings were evaluated in detail, and re-analysis of archived resected appendix specimens was carried out.
RESULTS: A total of 912 males and 709 females, from 16 to 94 years old, were included in the study and comprised 789 cases of suppurative appendicitis, 370 cases of appendix vermiformis, 243 cases of perforated gangrenous appendicitis, 53 cases of flegmaneous appendicitis, 32 cases of gangrenous appendicitis, and 134 (8.3%) cases of unusual histopathological findings. The unusual histopathological findings included fibrous obliteration (n = 62), enterobius vermicularis (n = 31), eosinophilic infiltration (n = 10), mucinous cystadenoma (n = 8), carcinoid tumor (n = 6), granulomatous inflammation (n = 5), adenocarcinoma (n = 4; one of them mucinous), and mucocele (n = 3), adenomatous polyp (n = 1), taenia sup (n = 1), ascaris lumbricoides (n = 1), appendiceal diverticula (n = 1), and B cell non-hodgkin lymphoma (n = 1). None of the 11 patients with subsequent diagnosis of tumor were suspected of cancer prior to the appendectomy.
CONCLUSION: Even when the macroscopic appearance of appendectomy specimens is normal, histopathological assessment will allow early diagnosis of many unusual diseases.
Core tip: Appendectomy is one of the most frequently performed surgical procedures worldwide. Although most of the resected appendectomy specimens show typical histopathologic findings, some (< 2%) show unusual histopathologic findings. The most common of these unusual features are primary or secondary appendiceal malignancies, mucocele, enterobisis, schistosomiasis, ascariasis, tuberculosis, amobiasis, and entometriosis. While some of the patients with unusual histopatholic findings require close follow-up and/or additional surgical treatment, others also necessitate antimicrobial therapy. Infectious appendicitis is responsible for a significant majority of the most commonly observed unusual features, especially in cases from developing nations in geographic regions with tropical and sub-tropical climates. Therefore, regardless of the underlying etiology, the results from histopathological examination of the resected appendectomy specimen may help guide the subsequent management of cases to prevent serious appendicular diseases.