PREVALENCE OF APPENDICEAL NEOPLASMS IN APPENDECTOMIES FOR ACUTE APPENDICITIS: A RETROSPECTIVE STUDY AT CLEMENTINO FRAGA FILHO UNIVERSITY HOSPITAL

PREVALENCE OF APPENDICEAL NEOPLASMS IN APPENDECTOMIES FOR ACUTE APPENDICITIS: A RETROSPECTIVE STUDY AT CLEMENTINO FRAGA FILHO UNIVERSITY HOSPITAL | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 12 June 2025 V1 Latest version Share on PREVALENCE OF APPENDICEAL NEOPLASMS IN APPENDECTOMIES FOR ACUTE APPENDICITIS: A RETROSPECTIVE STUDY AT CLEMENTINO FRAGA FILHO UNIVERSITY HOSPITAL Author : Matheus Miguel Luz Brusco 0009-0000-8622-546X [email protected] Authors Info & Affiliations https://doi.org/10.22541/au.174972614.45733392/v1 107 views 72 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Background and Objectives: Acute appendicitis is a common surgical emergency. Incidental discovery of appendiceal neoplasms during appendectomy, while rare, carries significant clinical implications. This study aimed to determine the prevalence of such incidental neoplasms in patients undergoing appendectomy for acute appendicitis at a university hospital in Brazil. Methods: We conducted a retrospective observational study of 106 patients who underwent appendectomy for acute appendicitis at the Clementino Fraga Filho University Hospital (HUCFF) between 2014 and 2023. Clinical and histopathological data were collected from electronic medical records. Results: Incidental appendiceal neoplasms were found in 2.83% (3/106) of patients. These included neuroendocrine tumors (n=1) and low-grade mucinous neoplasms (n=2). The mean age of patients with neoplasms was 54.67 years, with a female predominance (2/3). One patient with a neoplasm died postoperatively; one of the remaining two required a subsequent right hemicolectomy. Conclusions: Histopathological examination of all appendectomy specimens is crucial for identifying incidental appendiceal neoplasms. The prevalence in our institution (2.83%) was higher than some literature reports, potentially reflecting our patient population characteristics. Standardized record-keeping is essential, and further research could refine management strategies for these conditions. Keywords: acute appendicitis, appendectomy, incidental appendiceal neoplasm, neuroendocrine tumor, mucinous neoplasm. Introduction Acute appendicitis, an inflammation of the vestigial vermiform appendix, is one of the most common causes of acute abdomen. Its management can be non-surgical, with antibiotics alone for uncomplicated cases, or, more commonly, surgical, with the removal of the appendix (appendectomy). In this context, acute appendicitis is one of the most frequent indications for emergency surgery worldwide and, therefore, becomes part of the general surgeon’s daily routine, including during their training. Although the most frequent cause of acute appendicitis is the obstruction of the organ’s lumen, whether by fecaliths, lymphoid hyperplasia, or other inflammatory causes, a significant number of appendectomies incidentally reveal the presence of neoplasms. The prevalence of these neoplasms in appendectomies for acute appendicitis is rare but relevant, with rates ranging from 0.5% to 1% of cases [1]. Among the types of appendix neoplasms, neuroendocrine tumors (NETs) stand out, representing the most common form, followed by adenocarcinomas and low- or high-grade mucinous tumors. These neoplasms often do not present clear symptoms before surgery and are discovered only in postoperative histopathological examinations. Early detection of these conditions can have significant implications for the patient’s prognosis, especially in cases of more aggressive tumors, such as adenocarcinoma. The study of the prevalence of appendiceal neoplasms in patients undergoing appendectomy for acute appendicitis is fundamental to improving diagnostic, management, and follow-up strategies for patients, particularly those who present risk factors for malignancy, such as advanced age and atypical intraoperative findings. Materials and Methods This is an observational, retrospective, and single-center study, linked to the medical residency completion work in General Surgery at Clementino Fraga Filho University Hospital (HUCFF), involving patients who underwent appendectomy from January 1, 2014, to December 31, 2023. All patients who underwent appendectomy, whether by laparoscopic or conventional route, for acute appendicitis, on an emergency basis, were included in the study. Ethics Statement: The study did not require ethics committee approval due to its retrospective nature and the use of fully anonymized data. The requirement for informed consent was waived as the researchers did not have access to information that could identify individual participants during or after data collection. The data were accessed for research purposes on October 22, 2024, through the institutional electronic medical record system Medtrak. The descriptor “appendectomy” was used for the search. Cases in which appendectomy was part of a more complex surgery were excluded. Clinical data, such as sex, age at the time of surgery, procedure performed, and histopathological analysis of the appendix, were extracted from HUCFF’s electronic medical record (ProntHU). In cases of diagnosis of malignant appendiceal neoplasm, the physical medical record, pathological staging, preoperative ultrasonographic findings, indication for revisional surgery, use of adjuvant or palliative chemotherapy, and oncological follow-up were also evaluated. Statistical analysis was performed using descriptive statistics. Categorical variables were presented as frequencies and percentages, and continuous variables as means, medians, and ranges, as appropriate. Results From the data obtained in Medtrak, 118 patients who underwent appendectomy between January 2014 and December 2023 were identified. After analyzing the medical records and excluding those that did not meet the established criteria, 106 patients were selected (See Figure 1 for flowchart). The annual average of appendectomies was 10.6 (Table I). Among them, 53 patients (50%) underwent appendectomy exclusively by videolaparoscopy, while 51 (48.11%) underwent the procedure exclusively by conventional route. There were 2 cases (1.89%) in which the laparoscopic technique was converted to the conventional one (Table II). No histopathological report was found in 1 (0.94%) of the patients, despite an active search in the pathology department. Regarding the epidemiology of the included patients, 52 (49.06%) were female and 54 (50.94%) were male (See Figure S1). The mean age was 44.13 years, with a median of 43.5 years and a mode of 25 years. The minimum age was 13 years (in two patients) and the maximum was 92 years (See Figure S2). Incidental findings of appendiceal neoplasm were identified in only 3 (2.83%) cases: 1 (0.94%) corresponded to low-grade NET (G1), and 2 (1.89%) to low-grade mucinous neoplasms (See Figure S3). Of these cases, 2 (66.7%) were female patients and 1 (33.3%) was male (See Figure S4), with a mean age of 54.67 years. The annual incidence was 0.3 cases, representing an incidence rate of 0.28%. The year with the highest incidence was 2018, with 2 cases, followed by 2019, with 1 case (See Figure S5). Only 1 of the patients with neoplasm underwent the laparoscopic technique. The patient diagnosed with NET died in the postoperative period. Among the cases of low-grade mucinous neoplasm, both were staged as pT3. However, after the initial surgical procedure, reintervention occurred in only one of the patients, who underwent a right hemicolectomy. Histopathological analysis of the surgical specimen revealed low-grade adenocarcinoma implants in the cecum. The time between appendectomy and reoperation was 86 days. Both patients remain under follow-up at our hospital to date, with a 5-year survival. Discussion Acute appendicitis is one of the most common hospital emergencies, with an annual incidence of about 100 cases per 100,000 people. This condition predominantly affects young people between 10 and 30 years old, with a higher prevalence in the 10 to 19 age group. Although it occurs in both sexes, men have an 8.6% lifetime risk, while women have a 6.7% risk [1]. In our analysis, despite also predominating among young adults, there was a wider distribution between the sexes and a slightly higher mean age than the average reported in the literature [2]. This age difference and demographic profile may reflect regional variations and specific characteristics of the population served at our institution. From a pathophysiological point of view, the inflammatory process usually begins with the obstruction of the appendiceal lumen, caused by factors such as fecaliths, lymphoid hyperplasia, or, occasionally, tumors. This obstruction leads to increased intraluminal pressure, ischemia, and necrosis of the appendix wall, creating favorable conditions for bacterial proliferation, mainly Escherichia coli and Bacteroides fragilis [3]. Although acute appendicitis is considered a benign condition, the incidental occurrence of appendiceal neoplasms reinforces the need for careful histopathological evaluation of surgical specimens. In our study, the prevalence of neoplasms was 2.83%, above the range documented in the literature (0.5% to 1%) [4]. This increase may be related to the population profile of our hospital and greater diagnostic accuracy in recent years. Appendiceal neoplasms, although uncommon, have significant clinical implications, highlighting the importance of adequate planning in postoperative follow-up. Among appendiceal neoplasms, NETs and mucinous tumors were the most frequent. NET, present in 0.94% of cases, is the most common neoplasm of the appendix, with a prevalence of 0.3% to 0.9% in appendectomies performed for suspected acute appendicitis [5]. Generally low-grade, these tumors have a less aggressive clinical behavior, and management varies according to size and staging. Standard treatment for NETs diagnosed after appendectomy recommends right hemicolectomy associated with lymphadenectomy of the ileocolic and right colic arteries for patients with tumors larger than 2 cm. For those smaller, between 1 and 2 cm, hemicolectomy is indicated in the presence of deep mesoappendiceal invasion (> 3 mm), positive or unclear margins, high proliferative rate (grade ≥ 2), lymphovascular invasion, and mixed histology (goblet cell adenocarcinoma). Well-differentiated tumors less than 1 cm, or between 1.0 and 1.9 cm without the mentioned factors, can be treated with simple appendectomy alone [6]. In our study, the patient diagnosed with NET died two days after undergoing appendectomy, with the immediate cause of death being septic shock and acute respiratory distress syndrome, a consequence of complicated appendicitis with perforation and diffuse fecal peritonitis. Based on our analysis, right hemicolectomy would possibly have been indicated for this patient, as the tumor measured about 2.5 cm in its largest axis, in addition to infiltrating the muscularis propria and focally the serosa. The mucinous tumors represented 1.89% of the cases. Although they may present a more indolent behavior, there is prognostic importance associated with the risk of progression to pseudomyxoma peritonei in cases of appendiceal perforation. Post-appendectomy management varies according to the pathology found. In cases of low- or high-grade lesions completely resected, confined to the appendix, and unperforated, no additional treatment is necessary. However, if there are microscopically positive proximal margins, right hemicolectomy may be chosen. In the case of well-differentiated (G1) localized mucinous adenocarcinoma of the appendix completely resected, surveillance alone is suggested, given the low rate of lymphatic involvement and lack of survival benefit with hemicolectomy. For moderately (G2) or poorly differentiated (G3) ones, right hemicolectomy is recommended, due to higher rates of lymphatic involvement, in addition to evaluation for adjuvant chemotherapy [7]. In our study, only one of the patients with low-grade mucinous neoplasm underwent right hemicolectomy after appendectomy due to the extent of tumor invasion, evidenced in the histopathological analysis of the surgical specimen, demonstrating the importance of rigorous oncological follow-up. Continuous surveillance and possible surgical reinterventions are essential for the control and survival of these patients. The analysis of histopathological findings also indicated a greater predisposition of the female sex to appendiceal neoplasms, coinciding with literature data [8]. Although the mechanisms of this predisposition are not completely elucidated, this data may guide screening strategies. Furthermore, the mean age of patients with an incidental diagnosis of neoplasms was higher than that of others undergoing appendectomy, corroborating studies that associate advanced age with a higher risk of malignancy [9]. Thus, for older patients or those with atypical intraoperative findings, more rigorous follow-up is justified, with imaging exams and periodic oncological monitoring. This study has limitations inherent to its retrospective and single-center nature, which may impact the generalization of data to other populations. The absence of a standardized follow-up protocol for incidental neoplasms in our institution also makes it difficult to compare oncological outcomes. Furthermore, the lack of complete histopathological reports in some cases may have underestimated the true incidence of neoplasms. Conclusions The histopathological analysis of appendectomy specimens is essential for identifying significant clinical conditions, such as incidental neoplasms, which can directly impact patient management and prognosis. The findings of this study reinforce the importance of a careful histopathological evaluation in all cases of appendectomy, regardless of the initial clinical context, since, despite the low number of appendectomies performed in our unit, an increased prevalence of appendiceal neoplasms was observed. This data may reflect the demographic and clinical profile of the population served at our institution. The relevance of standardizing records is also highlighted, given that the absence of a histopathological report in one of the analyzed cases underscores the need for greater rigor in documentation to ensure quality of care and patient safety. Future investigations, with longer follow-up times and more representative samples, may contribute to a better understanding of regional variations and improve management strategies for appendiceal neoplasms. Acknowledgments The author thanks Fernanda Alonso Rodriguez Fleming for her insightful discussions and general support during the preparation of this manuscript. References 1. Addiss DG, Shaffer N, Fowler BS, Tauxe RV: The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol 1990;132:910-925. 2. Golz RA, Flum DR, Sanchez SE, et al.: Geographic Association Between Incidence of Acute Appendicitis and Socioeconomic Status. JAMA Surg 2020;155:330-338. 3. Liang MK, Andersson RE, Jaffe BM, Berger DH: The Appendix. In Brunicardi FC, Andersen DK, Billiar TR, et al. (eds). Schwartz’s Principles of Surgery. 10th ed. New York: McGraw-Hill Education, 2015. 4. Teixeira FJR, Couto Netto SD, Akaishi EH, et al.: Acute appendicitis, inflammatory appendiceal mass and the risk of a hidden malignant tumor: a systematic review of the literature. World J Emerg Surg 2017;12:12. 5. Goede AC, Caplin ME, Winslet MC: Carcinoid tumour of the appendix. Br J Surg 2003;90:1317-1322. 6. Boudreaux JP, Klimstra DS, Hassan MM, et al.: The NANETS consensus guideline for the diagnosis and management of neuroendocrine tumors: well-differentiated neuroendocrine tumors of the Jejunum, Ileum, Appendix, and Cecum. Pancreas 2010;39:753-766. 7. Govaerts K, Lurvink RJ, De Hingh IHJT, et al.: Appendiceal tumours and pseudomyxoma peritonei: Literature review with PSOGI/EURACAN clinical practice guidelines for diagnosis and treatment. Eur J Surg Oncol 2021;47:11-35. 8. Sandor A, Modlin IM: A retrospective analysis of 1570 appendiceal carcinoids. Am J Gastroenterol 1998;93:422-428. 9. Salazar MC, Canavan ME, Chilakamarry S, et al.: Appendiceal Cancer in the National Cancer Database: Increasing Frequency, Decreasing Age, and Shifting Histology. J Am Coll Surg 2022;234:1082-1089. Supplementary Material File (table i.docx) Download 14.23 KB File (table ii.docx) Download 14.19 KB Information & Authors Information Version history V1 Version 1 12 June 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Authors Affiliations Matheus Miguel Luz Brusco 0009-0000-8622-546X [email protected] Universidade Federal do Rio de Janeiro Departamento de Cirurgia View all articles by this author Metrics & Citations Metrics Article Usage 107 views 72 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Matheus Miguel Luz Brusco. PREVALENCE OF APPENDICEAL NEOPLASMS IN APPENDECTOMIES FOR ACUTE APPENDICITIS: A RETROSPECTIVE STUDY AT CLEMENTINO FRAGA FILHO UNIVERSITY HOSPITAL. Authorea . 12 June 2025. DOI: https://doi.org/10.22541/au.174972614.45733392/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. 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