Unusual histopathological findings in appendectomy specimens: a retrospective analysis and literature review

Abstract

Aim: To document unusual findings in appendectomy specimens.

Methods: The clinicopathological data of 5262 patients who underwent appendectomies for presumed acute appendicitis from January 2006 to October 2010 were reviewed retrospectively. Appendectomies performed as incidental procedures during some other operation were excluded. We focused on 54 patients who had unusual findings in their appendectomy specimens. We conducted a literature review via the PubMed and Google Scholar databases of English language studies published between 2000 and 2010 on unusual findings in appendectomy specimens.

Results: Unusual findings were determined in 54 (1%) cases by histopathology. Thirty were male and 24 were female with ages ranging from 15 to 84 years (median, 32.2 ± 15.1 years). Final pathology revealed 37 cases of enterobiasis, five cases of carcinoids, four mucinous cystadenomas, two eosinophilic infiltrations, two mucoceles, two tuberculosis, one goblet-cell carcinoid, and one neurogenic hyperplasia. While 52 patients underwent a standard appendectomy, two patients who were diagnosed with tuberculous appendicitis underwent a right hemicolectomy. All tumors were located at the distal part of the appendix with a mean diameter of 6.8 mm (range, 4-10 mm). All patients with tumors were alive and disease-free during a mean follow-up of 17.8 mo. A review of 1366 cases reported in the English literature is also discussed.

Conclusion: Although unusual pathological findings are seldom seen during an appendectomy, all appendectomy specimens should be sent for routine histopathological examination.

Keywords: Appendicitis; Carcinoid; Enterobius vermicularis; Goblet cell carcinoid; Mucocele; Unusual findings.

Figure 1

Unusual histopathologic findings. A: Adult of E.Vermicularis in appendices (HE, × 200); B: Eosinophilic appendicitis: diffuse eosinophilic infiltrate in lamina propria (HE, × 200); C: Carcinoid tumor of classic type is formed by solid nest of small monotonous cells with occasional acinar formation (HE, × 100); D: Microglandular goblet cell carcinoma. Acute appendicitis with a diffusely infiltrating goblet cell neoplasm. tumor cells infiltrated muscularis propria (HE, × 200); E: Mucosel. Dilatation of lumen by mucinous secretion, thin appendiceal wall. Mucin is protruding into surrounding fatty tissue (HE, × 40); F: Mucinous cystadenoma of appendix. Typical epithelium of a cystadenoma with pseudostratified, columnar cells containing elonged, crowded, hyperchromatic nuclei and scattered goblet cells with mucus in cavity (HE, × 100); G: Neurogenous hyperplasia of appendix. The proliferating spindle cells shown in this photography (HE, × 200); H: Tuberculous appendicitis. Granuloma which contain a caseating center surrounded by epithelioid cells, lymphocytes and histiocytes. A giant cell is present in the granuloma (HE, × 20).

Figure 2

Worldwide distribution of the 1366 cases defined as ''unusual findings''. Tumor: Carcinoid, goblet cell carcinoid, mucocele, appendix adenocarcinoma, lymphoma, mucinous cystadenoma and adenocarcinoma, polypoid lesions, leukemia, gastrointestinal stromal tumor, dysplastic change; Benign: Non-tumoral causes.