Survival among 148 patients with an incidentally detected appendiceal tumours at surgery for acute appendicitis: a population-based cohort follow-up study

PURPOSE

To investigate the long-term prognosis of appendiceal tumours incidentally detected at appendicectomy for suspicion of benign appendicitis.

METHODS

A retrospective register-based single centre cohort study was carried out, using data from the local acute appendicectomy quality register of cases operated on at the Department of Surgery, South General Hospital, Stockholm, Sweden. The local colorectal cancer register was also used to identify appendix tumours. The study period was between January 2004 and January 2023. Survival was calculated according to the Kaplan-Meier method.

RESULTS

A total of 11,888 patients were registered in the acute acute appendicectomy register, 54% males and 46% females, median age 32 (Q1 = 21, Q3 = 47) (with 33.7% were 41 years or older). From the appendicectomy and colorectal registers 148 (1.2% of the total cohort) appendiceal tumours were found; 60% in females and 40% in males, median age 56 (Q1 = 43, Q3 = 70) (with 78.4% being 41 years or older). Tumours found were: Low grade Appendiceal Mucinous Neoplasms (LAMN, N = 64); Neuroendocrine Tumours (NET N = 24); adenocarcinomas or other form of carcinomas (N = 57); and adenomas (N = 3). The overall 5-year survival in patients operated for LAMN was 96.8%, for NET 93.3% and for adenocarcinoma 69.7%. The overall 5-year survival for all tumour patients was 85.7%. For the younger patients (< 51 years) with LAMN and NET, almost all survived to the end of follow-up. Survival of patients in the carcinoma group was statistically significantly lower than for the LAMN and NET groups, especially in females 51 years or older. In the group of tumour patients undergoing surgery (n = 146), primary surgery was laparoscopic in 47% and open in 52%. Two patients did not undergo surgery due to widespread disease. In 64% of cases operation was acute, whereas it was delayed and/or planned in 34%. Most procedures were laparoscopic appendicectomy 36%, followed by open appendicectomy 30%, right-sided hemicolectomy 14.6% (open 11.6% and laparoscopic 3%, acute operation 5.5%), ileocaecal resection 5% (acute operation 3.4%), and staging laparoscopy 7%. In 38% of the operated patients the tumour was discovered incidentally at histopathology examination. Two patients had CRS and HIPEC as the initial operation. Forthy-three per cent of the 146 tumour patients operated underwent a second procedure: CRS and HIPEC in 23.3% and right-sided hemicolectomy in 13.6% (laparoscopic 8.2% open 5.4%).

CONCLUSION

Survival was high for patients with incidentally detected appendiceal LAMN or NET, but not so for carcinoma. Survival was lower in the carcinoma group older than 50 years, especially those sick and females.

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.

Incidence of occult appendiceal neoplasm in patients over 40 years with acute appendicitis: A single-institution review

OBJECTIVE

To investigate the incidence of occult appendiceal neoplasm in patients aged 40 years and over who underwent appendicectomy for appendicitis.

METHODS

The clinical coding electronic database was used to identify patients aged 40 years and over who were diagnosed with appendicitis from September 2010 to September 2022. Patients were included if they were managed operatively.

DESIGN

Retrospective cohort study.

SETTING

Modified Monash category 3 (large rural town).

PARTICIPANTS

Patients aged 40 years and over undergoing appendicectomy for appendicitis.

MAIN OUTCOME MEASURES

Incidence of appendiceal neoplasm within appendicectomy specimen.

RESULTS

A total of 279 patients aged 40 years and over underwent appendicectomy, with a median age of 53 years (range 40-95). Nineteen patients (7%) were found to have a primary neoplastic lesion within the appendix: seven neuroendocrine neoplasms (37%), six sessile serrated lesions (32%), two colonic-type adenocarcinoma (11%), two goblet cell adenocarcinoma (11%) and two appendiceal mucinous neoplasms (11%). Additionally, one patient had a metastatic adenocarcinoma of pancreaticobiliary aetiology.

CONCLUSIONS

Occult appendiceal neoplasm was higher than reported in the literature in our cohort. This would support appendicectomy as the treatment of choice for patients aged 40 years and over with acute appendicitis and caution against nonoperative management in this demographic.

Primary appendiceal MALT lymphoma clinically masquerading as chronic appendicitis: A case report

INTRODUCTION AND IMPORTANCE

Mucosal associated lymphoid tissue (MALT) lymphomas are a type of extranodal indolent lymphoma. They appear in areas ordinarily devoid of lymphoid tissues and are frequently preceded by chronic antigenic stimulation. Primary MALT lymphoma is an extremely rare variant in the appendix.

CASE PRESENTATION

A 22-year-old man presented with recurrent abdominal pain of three months. CT scan of the abdomen showed appendiceal wall thickening with ileo-colic lymphadenopathy. The patient was managed with right hemicolectomy and the histopathological examination showed MALT lymphoma.

CLINICAL DISCUSSION

MALT lymphomas of the appendix are extremely rare. Chronic appendicitis is an uncommon but possible clinical presentation. Although imaging techniques are essential for making a diagnosis, histological analysis is what leads to a final diagnosis. While there are no specific recommendations for treating appendiceal MALTomas, prior case reports indicate that appendectomy and surveillance may be sufficient.

CONCLUSION

Primary MALT lymphoma is extremely uncommon in the appendix. It is indolent in nature and can manifest clinically as chronic appendicitis. The management for localized disease is surgery or radiotherapy. The prognosis is excellent regardless of the initial treatment modality.

Analysis of appendiceal neoplasms in 1,423 appendectomy specimens: a 10-year retrospective cohort study from a single institution

OBJECTIVE

This study aimed to reveal the incidence, clinicopathological, and oncological outcomes of appendiceal neoplasms.

METHODS

This is a retrospective cohort study from a single institution. Patients with a pathological diagnosis of malignancy who underwent appendectomy between January 2011 and 2021 were included in the study, and groups were formed according to pathological type. Clinical, pathological, and oncological results were compared in these groups.

RESULTS

The incidence of neoplasia was 2.38% (n=34) in a cohort of 1,423 appendectomy cases. Of the cases, 56% (n=19) were female. The median age in the entire cohort was 55.5 (range: 13-106) years. In the cohort, the rate of neuroendocrine tumor mucinous cystadenoma adenocarcinoma, and low-grade appendiceal mucinous neoplasm, according to the American Joint Committee on Cancer classification of appendiceal neoplasms, was 32.3% (n=11), 26.4% (n=9), 26.4% (n=9), and 14.7% (n=5), respectively. Neuroendocrine tumor patients (median age: 35 years) were younger than the other groups (p=0.021). Secondary complementary surgery was performed in 66.7% (n=6) of adenocarcinoma patients and 27.3% (n=3) of neuroendocrine tumor patients. Right hemicolectomy was performed in all neuroendocrine tumor patients requiring secondary surgery, while right hemicolectomy was performed in three adenocarcinoma patients and cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in three adenocarcinoma patients. After a median follow-up of 44.4 months (95% confidence interval: 18.6-70.1), the mean survival rate was 55% in appendiceal adenocarcinoma patients compared to 100% in neuroendocrine tumor patients.

CONCLUSION

Appendiceal neoplasms are rare but remain an important cause of mortality. Appendiceal adenocarcinomas are associated with poorer oncological outcomes compared to other neoplasms.

Progression to pseudomyxoma peritonei in patients with low grade appendiceal mucinous neoplasms discovered at time of appendectomy

BACKGROUND

The discovery of a low grade appendiceal mucinous neoplasm (LAMN) during appendectomy is a rare scenario. These neoplasms can progress to pseudomyxoma peritonei (PMP), however the incidence of progression is not well known.

METHODS

The records of all patients with a diagnosis of localized LAMN found during appendectomy were identified, and demographic, tumor, surveillance, and outcome variables were analyzed.

RESULTS

Progression to PMP occurred in 20% of patients in an average of 12.4 months after appendectomy with median follow-up of 18 months. Tumor variables such as margin positivity, appendiceal perforation, and presence of extra-appendiceal acellular mucin or mucinous epithelium on the serosal were not significantly associated with progression.

CONCLUSIONS

During an average follow-up period of 18 months after surgery, progression to PMP occurred in a fifth of patients. It is difficult to predict which patients will progress, therefore cross-sectional imaging surveillance is recommended for all patients.

Necessity of posttreatment surveillance for low-grade appendiceal mucinous neoplasms

BACKGROUND AND OBJECTIVES

Low-grade appendiceal mucinous neoplasms (LAMNs) are generally treated by surgical resection, but posttreatment surveillance protocols are not well-established. The objectives of this study were to characterize posttreatment surveillance and determine the risk of recurrence following surgical resection of LAMN.

METHODS

Patients who underwent surgical resection of localized LAMNs in an 11-hospital regional healthcare system from 2000 to 2019 were identified. Posttreatment surveillance regimens were characterized, and rates of disease recurrence were evaluated.

RESULTS

A total of 114 patients with LAMNs were identified. T-category was pTis for 92 patients (80.7%), pT3 for 7 (6.1%), pT4a for 14 (12.3%), and pT4b for 1 (0.9%). Two patients (1.8%) had a positive resection margin. Posttreatment surveillance was performed for 39 (34.2%) patients and consisted of office visits for 32 (82%) patients, computerized tomography imaging for 30 (77%), magnetic resonance imaging for 5 (13%), colonoscopy for 15 (38%), and serum tumor marker measurement for 12 (31%). After a mean follow-up duration of 4.7 years, no patients experienced tumor recurrence.

CONCLUSIONS

Posttreatment surveillance is common among patients with LAMNs. However, no patients experienced tumor recurrence, regardless of T-category or margin status, suggesting that routine surveillance following surgical resection of LAMN may be unnecessary.

Increased risk of malignancy for patients older than 40 years with appendicitis and an appendix wider than 10 mm on computed tomography scan: A post hoc analysis of an EAST multicenter study

BACKGROUND

The incidence of underlying malignancy in appendicitis ranges between 0.5% and 1.7%. We sought to identify the subset of patients with appendicitis who are at increased risk of appendiceal malignancy.

METHODS

Using the Eastern Association for the Surgery of Trauma Multicenter Study of the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous database, we included all patients from 28 centers undergoing immediate, delayed, or interval appendectomy between 2017 and 2018. Univariate then multivariable analyses were performed to compare patients with and without malignancy and to identify independent demographic, clinical, laboratory, and/or radiological predictors of malignancy. Akaike information criteria for regression models were used to evaluate goodness of fit.

RESULTS

A total of 3,293 patients were included. The median age was 38 (27-53) years, and 46.5% were female patients. On pathology, 48 (1.5%) had an underlying malignancy (adenocarcinoma [60.4%], neuroendocrine [37.5%], and lymphoma [2.1%]). Patients with malignancy were older (56 [34.5-67] vs 37 [27-52] years, P < .001), had longer duration of symptoms before presentation (36-41 vs 18-23 hours, P = .03), and were more likely to have a phlegmon on imaging (6.3% vs 1.3%, P = .03). Multivariable analyses showed that an enlarged appendiceal diameter was independently associated with malignancy (odds ratio = 1.06, 95% confidence interval = 1.01-1.12; P = .01). The incidence of malignancy in patients >40 years with an appendiceal diameter >10 mm on computed tomography was 2.95% compared with 0.97% in patients ≤40 years old with appendiceal diameter ≤10 mm. The corresponding risk ratio for that population was 3.03 (95% confidence interval: 1.24-7.42; P = .02).

CONCLUSION

The combination of age >40 and an appendiceal diameter >10 mm is associated with a greater than 3-fold increased risk of malignancy in patients presenting with appendicitis.

Preoperative Factors Associated with Appendiceal Tumors in Nonelective Appendectomy

Background: The rates of incidental appendiceal neoplasms after appendectomy performed for acute appendicitis is <2%. To date, no large studies have investigated the preoperative risk factors or imaging findings associated with incidental appendiceal tumors that present as appendicitis. Our study aims to identify preoperative factors that are associated with an increased risk of appendiceal tumors in patients who present with signs and symptoms of acute appendicitis. Materials and Methods: Using the targeted appendectomy American College of Surgeons National Surgical Quality Improvement Program database, we identified patients who underwent nonelective appendectomy for acute appendicitis in 2016. Patients with final pathology consistent with a tumor were compared with those with only appendicitis. A nonmatched case/control method was used to pull a random sample from the appendicitis cohort using a 1:4 ratio (tumor: acute appendicitis) to obtain adequate power for comparison. Preoperative patient variables and imaging findings were investigated using stepwise logistic regression to identify variables associated with appendiceal tumor. Results: Following multivariate analysis, preoperative imaging read of "indeterminate" and "not consistent with appendicitis," female gender, increased age, and lower preoperative white blood cell (WBC) count were significant predictors of tumor causing symptoms of appendicitis. The odds of having tumor pathology were significantly increased in patients with preoperative imaging of "indeterminate" and "not consistent with appendicitis." The odds of having tumor pathology were 82% higher for females than for males, increased by 2% for every 1-year increase in age, and increased by 3% for every one-unit decrease in WBC count. Conclusion: While incidental appendiceal tumors can present as acute appendicitis, 3 patient variables and one imaging finding were identified that may increase suspicion for appendiceal tumors. Consideration should be given to patients with these associated risk factors for additional preoperative consultation in addition to the potential for intraoperative pathology consultation.

Post-inflammatory mucosal hyperplasia and appendiceal diverticula simulate features of low-grade appendiceal mucinous neoplasms

Post-inflammatory mucosal hyperplasia and appendiceal diverticulosis simulate mucinous neoplasms, causing diagnostic confusion. Distinction between neoplasia and its mimics is particularly important since many authorities now consider all appendiceal mucinous neoplasms to be potentially malignant. The purpose of this study was to identify clinicopathologic and molecular features that may distinguish appendiceal mucinous neoplasms from non-neoplastic mimics. We retrospectively identified 92 mucinous lesions confined to the right lower quadrant, including 55 non-neoplastic examples of mucosal hyperplasia and/or diverticulosis and 37 low-grade neoplasms. Presenting symptoms, radiographic findings, appendiceal diameter, appearances of the lamina propria, non-neoplastic crypts, and epithelium, as well as mural changes were recorded. Twenty non-neoplastic lesions were subjected to KRAS mutational testing. Non-neoplastic appendices were smaller (p < 0.05) and more likely to present with symptoms of appendicitis (p < 0.05) than neoplasms. While post-inflammatory mucosal hyperplasia and diverticula often showed goblet cell-rich epithelium, extruded mucin pools, and patchy mural alterations with fibrosis, they always contained non-neoplastic crypts lined by mixed epithelial cell types and separated by lamina propria with predominantly preserved wall architecture. On the other hand, mucinous neoplasms lacked normal crypts (p < 0.05) and showed decreased lamina propria (p < 0.05) with diffusely thickened muscularis mucosae and lymphoid atrophy. Six (30%) non-neoplastic lesions contained KRAS mutations, particularly those containing goblet cell-rich hyperplastic epithelium. We conclude that distinction between neoplastic and non-neoplastic mucinous appendiceal lesions requires recognition of key morphologic features; KRAS mutational testing is an unreliable biomarker that cannot be used to assess biologic risk or confirm a diagnosis of neoplasia.

Nonoperative Management of Uncomplicated Appendicitis Among Privately Insured Patients

Importance

Health care professionals have shown significant interest in nonoperative management for uncomplicated appendicitis, but long-term population-level data are lacking.

Objective

To compare the outcomes of nonoperatively managed appendicitis against appendectomy.

Design, Setting, and Participants

This national retrospective cohort study used claims data from a private insurance database to compare patients admitted with uncomplicated appendicitis from January 1, 2008, through December 31, 2014, undergoing appendectomy vs nonoperative management. Coarsened exact matching was applied before multivariate analysis to reduce imbalance between groups. Data were analyzed from February 12 through May 1, 2018.

Exposures

Appendectomy (control arm) or nonoperative management (treatment arm).

Main Outcomes and Measures

Short-term primary clinical outcomes included emergency department visits, hospital readmission, abdominal abscess, and Clostridium difficile infections. Long-term primary clinical outcomes were small-bowel obstructions, incisional hernias, and appendiceal cancers. Nonoperative management failure was defined by hospital readmission with appendicitis diagnosis and an appendicitis-associated operation or procedure. Secondary outcomes included number of follow-up visits, length and cost of index hospitalization, and total cost of appendicitis-associated care. Covariates included age, sex, region, insurance plan type, admission year, and Charlson comorbidity index.

Results

Of 58 329 patients with uncomplicated appendicitis (52.7% men; mean [SD] age, 31.9 [16.5] years), 55 709 (95.5%) underwent appendectomy and 2620 (4.5%) underwent nonoperative management. Patients in the nonoperative management group were more likely to have appendicitis-associated readmissions (adjusted odds ratio, 2.13; 95% CI, 1.63-2.77; P < .001) and to develop an abscess (adjusted odds ratio, 1.42; 95% CI, 1.05-1.92; P = .02). Patients in the nonoperative management group required more follow-up visits in the year after index admission (unadjusted mean [SD], 1.6 [6.3] vs 0.3 [1.4] visits; adjusted +1.11 visits; P < .001) and had lower index hospitalization cost (unadjusted mean [SD], $11 502 [$9287] vs $13 551 [$10 160]; adjusted -$2117, P < .001), but total cost of appendicitis care was higher when follow-up care was considered (unadjusted, $14 934 [$31 122] vs $14 186 [$10 889]; adjusted +$785; P = .003). During a mean (SD) of 3.2 (1.7) years of follow-up, failure of nonoperative management occurred in 101 patients (3.9%); median time to recurrence was 42 days (interquartile range, 8-125 days). Among the patients who experienced treatment failure, 44 did so within 30 days.

Conclusions and Relevance

According to results of this study, nonoperative management failure rates were lower than previously reported. Nonoperative management was associated with higher rates of abscess, readmission, and higher overall cost of care. These data suggest that nonoperative management may not be the preferred first-line therapy for all patients with uncomplicated appendicitis.

Communication and management of incidental pathology in 1,214 consecutive appendicectomies; a cohort study

BACKGROUND

Important incidental pathology requiring further action is commonly found during appendicectomy, macro- and microscopically. We aimed to determine whether the acute surgical unit (ASU) model improved the management and disclosure of these findings.

METHODS

An ASU model was introduced at our institution on 01/08/2012. In this retrospective cohort study, all patients undergoing appendicectomy 2.5 years before (Traditional group) or after (ASU group) this date were compared. The primary outcomes were rates of appropriate management of the incidental findings, and communication of the findings to the patient and to their general practitioner (GP).

RESULTS

1,214 patients underwent emergency appendicectomy; 465 in the Traditional group and 749 in the ASU group. 80 (6.6%) patients (25 and 55 in each respective period) had important incidental findings. There were 24 patients with benign polyps, 15 with neuro-endocrine tumour, 11 with endometriosis, 8 with pelvic inflammatory disease, 8 Enterobius vermicularis infection, 7 with low grade mucinous cystadenoma, 3 with inflammatory bowel disease, 2 with diverticulitis, 2 with tubo-ovarian mass, 1 with secondary appendiceal malignancy and none with primary appendiceal adenocarcinoma. One patient had dual pathologies. There was no difference between the Traditional and ASU group with regards to communication of the findings to the patient (p = 0.44) and their GP (p = 0.27), and there was no difference in the rates of appropriate management (p = 0.21).

CONCLUSION

The introduction of an ASU model did not change rates of surgeon-to-patient and surgeon-to-GP communication nor affect rates of appropriate management of important incidental pathology during appendectomy.

Tubulo-villous adenoma of the appendix: A case report and review of the literature

•

Tubulo-villous adenoma is a rare benign appendiceal neoplasm.

•

This neoplasm is often asymptomatic and occasionally discovered at surgery.

•

Acute appendicitis is the most common clinical presentation.

•

Pre-operative diagnosis, even with the help of radiological imaging, is difficult.

•

Appendectomy is considered the correct treatment.

Introduction

Tubulo-villous adenoma is a rare benign appendiceal neoplasm often asymptomatic with the most clinical manifestation that resembles acute appendicitis. Pre-operative diagnosis is difficult by its rarity and the absence of typical symptoms. Adequate treatment is surgical resection.

Presentation of case

A 69-year-old male was admitted to the Emergency Department with a two-day history of abdominal pain associated with constipation. Abdominal examination revealed abdominal pain localized, at deep palpation, in the right iliac fossa and in hypogastrium without obvious muscle guarding or rebound tenderness. Laboratory tests showed a normal white blood cell count with 82.3% neutrophils and high C-reactive protein level. After a negative abdominal ecography, the patient was evaluated by abdominal computed tomography, which revealed acute appendicitis. The patient was submitted to surgery and open appendectomy was performed. The post-operative course was uneventful and the patient was discharged on the 5^th post-operative day.

Discussion

Acute appendicitis may be a clinical manifestation of a benign appendiceal neoplasm. Pre-operative radiological investigations not always are useful for an early diagnosis that is mandatory because of the potential risk of malignant degeneration. Appropriate treatment of acute appendicitis is debated: some surgeons suggest operative treatment, but others advocate for non-operative management. In our case the patient was submitted to surgery avoiding the risk of diagnostic delay of neoplasm.

Conclusion

Appendiceal tubulo-villous adenoma is a rare neoplasm difficult to diagnose and suspect because of lack of pathognomonic symptoms and specific diagnostic signs. Acute appendicitis is the most common clinical presentation. Appendectomy is the appropriate treatment.