Increased Risk of Neoplasms in Adult Patients Undergoing Interval Appendectomy

Appendiceal Tumor Prevalence in Patients With Periappendicular Abscess

Importance

There are no large prospective cohort studies validating the previously reported high appendiceal tumor rate in patients with periappendicular abscess.

Objective

To confirm the appendiceal neoplasm rate associated with periappendicular abscess.

Design, Setting, and Participants

The Peri-Appendicitis Acuta Tumor prospective multicenter cohort study was conducted at 12 hospitals in Finland. All consecutive adult patients diagnosed with acute appendicitis were included, focusing on patients with imaging confirmed periappendicular abscess undergoing interval appendectomy or emergency appendectomy with available histopathology from December 3, 2020, through December 2, 2022. These data were analyzed from May 2023 to September 2024.

Interventions

Recommended treatment was initial antibiotics and, if needed, drainage, followed by interval appendectomy at 3 months.

Main Outcomes and Measures

The main outcome was appendiceal tumor rate associated with periappendicular abscess. Secondary outcomes included tumor histology and prognostic factors for appendiceal tumor (age, sex, body mass index, duration of symptoms, C-reactive protein level, white blood cell count, computed tomography findings, and tumor markers).

Results

There were 6165 consecutive patients with acute appendicitis. Of these, 396 patients (6.4%) presented with periappendicular abscess, with 9 patients declining to participate and 17 patients without available appendiceal histopathology, leaving 370 patients for the analysis (181 female [48.8%] and 189 male [51.2%]; median age, 58 [range, 18-90] years). Appendiceal tumor rate in patients with periappendicular abscess was 14.3% (53 of 370; 95% CI, 10.8%-17.9%), which was higher compared with uncomplicated acute appendicitis (14.3% vs 1.5%; 48 of 3170; 95% CI, 1.1%-1.9%; P < .001) and complicated acute appendicitis without periappendicular abscess (14.3% vs 2.4%; 63 of 2599; 95% CI, 1.8%-3.0%; P < .001). Patient age (odds ratio, 1.06; 95% CI, 1.04-1.09; P < .001) was the only factor associated with periappendicular abscess tumor prevalence. A cutoff point of age 35 years with high sensitivity was chosen (area under the curve, 0.75; 95% CI, 0.68-0.82) and only 1 patient below this threshold presented with an appendiceal tumor (sensitivity, 98.1%; 95% CI, 94.5-100). Of the 54 tumors on 53 patients, there were 21 low-grade appendiceal mucinous neoplasms, 20 adenocarcinomas, 8 adenomas, and 5 neuroendocrine tumors. The complication rate of emergency appendectomy was higher than after interval appendectomy (31.3% [70 of 224] vs 4.8% [5 of 105], respectively [P < .001]).

Conclusions and Relevance

This large prospective cohort study confirmed a high appendiceal tumor rate associated with periappendicular abscess, especially in patients older than 35 years. At the least, all patients older than 35 years should undergo routine interval appendectomy.

Trial Registration

ClinicalTrials.gov Identifier: NCT04634448.

Exploring the mysterious mucinous appendiceal neoplasm

Mucinous neoplasms of the appendix comprise a group of diagnostically challenging lesions that have generated significant controversy and confusion throughout the years, given their potential for aggressive behavior despite very bland cytologic features. Numerous classification schemes have been proposed to characterize and stage these lesions, but confusion remains among pathologists, surgeons, and oncologists regarding diagnostic criteria, therapeutic implications, and overall prognosis. This review summaries the current recommended nomenclature, histologic characteristics of each entity, and helpful features to distinguish neoplasia from benign mimics.

Beyond acute appendicitis: a single-institution experience of unexpected pathology findings after 989 consecutive emergency appendectomy

INTRODUCTION

Appendiceal neoplasms (ANs) are rare, with an estimated incidence of around 1%: neuroendocrine tumours (NETs) and low-grade appendiceal mucinous neoplasms (LAMNs) comprise most cases. Most tumours are cured by appendectomy alone, although some require right hemicolectomy and intra-operative chemotherapy. The aim of the present study is to evaluate our institution's experience in terms of the prevalence of AN, their histological types, treatment and outcomes in adult patients undergoing emergency appendectomy.

MATERIAL AND METHODS

Single-centre retrospective cohort analysis of patients treated for acute appendicitis at a large academic medical centre. Patients with a diagnosis of acute appendicitis (AA) where further compared with patients with acute appendicitis and a histologically confirmed diagnosis of appendiceal neoplasm (AN).

RESULTS

A diagnosis of acute appendicitis was made in 1200 patients. Of these, 989 patients underwent emergency appendectomy. The overall incidence of appendiceal neoplasm was 9.3% (92 patients). AN rate increased with increasing age. Patients under the age of 30 had a 3.8% (14/367 patients) rate of occult neoplasm, whereas patients between 40 and 89 years and older had a 13.0% rate of neoplasm. No difference was found in clinical presentations and type of approach while we found a lower complicated appendicitis rate in the AN group.

CONCLUSION

ANs are less rare with respect to the literature; however, clinically, there are no specific signs of suspicious and simple appendicectomy appears to be curative in most cases. However, age plays an important role; older patients are at higher risk for AN. ANs still challenge the non-operative management concept introduced into the surgical literature.

High Incidence of Appendiceal Neoplasms in the Elderly: A Critical Concern for Non-Surgical Treatment

OBJECTIVE

Appendiceal neoplasms (ANs) are rare tumors that are often discovered incidentally during histopathological examinations. The increasing incidence of ANs is a critical issue in the non-operative management of acute appendicitis. This study aimed to document the temporal trends over a 12-year period by analyzing the clinical presentation, imaging findings, and histopathological features of ANs.

SUBJECTS AND METHODS

Health records of patients who underwent appendectomy from 2011 to 2022 were examined. Demographic and clinical data, laboratory results, imaging findings, and histopathological features were documented. The characteristics of both ANs and non-neoplastic cases were evaluated.

RESULTS

A total of 22,304 cases were identified, of which 330 (1.5%) were diagnosed with ANs. The odds ratio for ANs increased with age, with the highest odds ratio observed in patients aged 70 or older. Receiver Operating Characteristic analysis showed that age and appendiceal diameter were significant predictors of ANs. An optimal age cut-off point of 28.5 years was determined, yielding a sensitivity of 72% and a specificity of 64%. For appendiceal diameter, the optimal cut-off was found to be 9.5 mm, exhibiting a sensitivity of 77% and a specificity of 56%.

CONCLUSION

Although the incidence of ANs remains relatively low, a steady increase has been observed over the past decade. The increasing rate of ANs raises concerns regarding non-surgical management options. The results of this study highlight the importance of considering ANs as a potential diagnosis in older patients and in patients with an appendix diameter greater than 9.5 mm. These findings may have implications for treatment and management.

Benign multicystic mesothelioma of appendiceal origin treated by hyperthermic intraperitoneal chemotherapy: A case report

Introduction and importance

Peritoneal benign cystic mesothelioma is a rare benign tumor that originates from a mesothelial proliferative lesion of the peritoneum. However, proper surgical management remains unclear due to its low incidence. We report a clinical case of peritoneal benign cystic mesothelioma treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).

Case presentation

A 60-year-old female who underwent laparoscopic appendectomy in 2015 presented with abdominal pain in right lower quadrant area. Computed tomography of the abdomen and pelvis revealed a ruptured appendiceal mucocele or mucinous neoplasm, and several seeding-like small nodules in the greater omentum and right peritoneum. Cytoreductive surgery followed by HIPEC was performed; right hemicolectomy and lymph node dissection, omentectomy, and right abdominal partial peritonectomy. HIPEC with mitomycin was conducted for 90 min and an anastomosis between the ileum and colon was made after HIPEC. The pathologic results revealed the colonic mass was a multi-loculated cyst lined by mesothelial cells containing amorphous eosinophilic fibrinoid material, which are common features of benign cystic mesothelioma.

Clinical discussion

Peritoneal benign cystic mesothelioma is known as a borderline disease of mesothelial tumors. Because its etiology is unknown, treatment strategies are not determined.

Conclusion

Cytoreductive surgery followed by HIPEC can be considered to treat peritoneal benign cystic mesothelioma and prevent its malignant transformation.

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Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy can be considered to treat patients with peritoneal benign cystic mesothelioma.

Risk of appendiceal neoplasm after interval appendectomy for complicated appendicitis: A systematic review and meta-analysis

BACKGROUND

Non-operative management is often the treatment of choice in cases of complicated appendicitis and routine interval appendectomy is not usually recommended. Actually, recent studies show an alarming number of appendiceal neoplasms following interval appendectomy. The aim of this study is to evaluate the prevalence of appendiceal neoplasms and their histological types after interval appendectomy for complicated appendicitis in adults.

METHODS

A comprehensive literature search of the PubMed, Scopus and Web of Science databases was conducted according to the PRISMA statement. Studies reporting appendiceal neoplasm rates after interval appendectomy and histopathological characteristics were included. The most recent World Health Organization (WHO) classification of malignant tumours was considered. A pooled prevalence analysis for both prevalence and pathology was performed.

RESULTS

A total of eight studies was included: seven retrospective series and one randomized controlled trial. The pooled prevalence of neoplasms after interval appendectomy was 11% (95% CI 7-15; I2 = 37.5%, p = 0.13). Appendiceal mucinous neoplasms occurred in 43% (95% CI 19-68), adenocarcinoma in 29% (95% CI 6-51), appendiceal neuroendocrine neoplasm in 21% (95% CI 6-36), globet cell carcinoma in 13% (95% CI -2-28), adenoma or serrated lesions in 20% (95% CI -0-41) of cases.

CONCLUSION

The risk of appendiceal neoplasm in patients treated with interval appendectomy for complicated appendicitis is 11%; mucinous neoplasm is the most common histopathological type. Further studies should investigate this association in order to clarify the biological pathway and clinical implications.

Modern Management of the Appendix: So Many Options

Nonoperative management (NOM) of acute appendicitis is becoming more popular, especially in resource-strapped locations, to minimize hospital system costs. In uncomplicated cases of appendicitis, NOM can effectively treat the patient. It does carry a 39.1% risk of recurrence in 5 years, and operative management (OM) does not increase morbidity or risk of complication, so the authors recommend laparoscopic OM for uncomplicated appendicitis. For complicated cases of appendicitis, the authors recommend initial NOM with interval appendectomy in all patients. All appendicitis patients should undergo surveillance endoscopy if older than 40 years to rule out a contributing neoplasm.