University of Oulu

Mällinen, J., Vaarala, S., Mäkinen, M. et al. Int J Colorectal Dis (2019) 34: 1393.

Appendicolith appendicitis is clinically complicated acute appendicitis : is it histopathologically different from uncomplicated acute appendicitis

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Author: Mällinen, Jari1,2; Vaarala, Siina3,4; Mäkinen, Markus3,4;
Organizations: 1Department of Surgery, Oulu University Hospital, Oulu, Finland
2Division of Operative Care, Oulu University Hospital and Medical Research Center Oulu, University of Oulu, Oulu, Finland
3Cancer and Translational Medicine Research Unit, University of Oulu nad Department of Pathology, Oulu University Hospital, Oulu, Finland
4Medical Research Center Oulu, Oulu, Finland
5Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland
6Department of Surgery, University of Turku, Turku, Finland
7Satakunta Central Hospital, Pori, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
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Language: English
Published: Springer Nature, 2019
Publish Date: 2019-10-10


Purpose: Acute appendicitis may present as uncomplicated and complicated and these disease forms differ both epidemiologically and clinically. Complicated acute appendicitis has traditionally been defined as an appendicitis complicated by perforation or a periappendicular abscess, and an appendicolith represents a predisposing factor of complicated disease. There are histopathological differences between uncomplicated acute appendicitis and the previously established traditional forms of complicated acute appendicitis, but to our knowledge, the histopathological differences between uncomplicated acute appendicitis and complicated acute appendicitis presenting with an appendicolith have not yet been reported. The study purpose was to assess these differences with two prospective patient cohorts: (1) computed tomography (CT) confirmed uncomplicated acute appendicitis patients enrolled in the surgical treatment arm of the randomized APPAC trial comparing appendectomy with antibiotics for the treatment of uncomplicated acute appendicitis and (2) patients with CT-verified acute appendicitis presenting with an appendicolith excluded from the APPAC trial.

Methods: The following histopathological parameters were assessed: appendiceal diameter, depth of inflammation, micro-abscesses, density of eosinophils, and neutrophils in appendiceal wall and surface epithelium degeneration.

Results: Using multivariable logistic regression models adjusted for age, gender, and symptom duration, statistically significant differences were detected in the depth of inflammation ≤ 2.8 mm (adjusted OR 2.18 (95%CI: 1.29–3.71, p = 0.004), micro-abscesses (adjusted OR 2.16 (95%CI: 1.22–3.83, p = 0.008), the number of eosinophils and neutrophils ≥ 150/mm² (adjusted OR 0.97 (95%CI: 0.95–0.99, p = 0.013), adjusted OR 3.04 (95%CI: 1.82–5.09, p < 0.001, respectively).

Conclusions: These results corroborate the known clinical association of an appendicolith to complicated acute appendicitis.

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Series: International journal of colorectal disease
ISSN: 0179-1958
ISSN-E: 1432-1262
ISSN-L: 0179-1958
Volume: 34
Issue: 8
Pages: 1393 - 1400
DOI: 10.1007/s00384-019-03332-z
Type of Publication: A1 Journal article – refereed
Field of Science: 3121 General medicine, internal medicine and other clinical medicine
3126 Surgery, anesthesiology, intensive care, radiology
Funding: Open access funding provided by University of Oulu including Oulu University Hospital. The study was supported by government research grant awarded to Oulu University Hospital, Mary and Georg C. Ehrnrooth Foundation, The Instrumentarium Science Foundation and Finnish Medical Foundation.
Copyright information: © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.