Pelvic Diagnostic Challenges of Appendiceal Neoplasm Mimicking a Hematosalpinx: A Case Report.

Appendiceal mucinous neoplasms are rare and can be easily misdiagnosed as adnexal masses. Fertility is a concern in cases requiring cytoreductive surgery involving the ovaries and if hyperthermic intraperitoneal chemotherapy is considered. We present the case of a 35-year-old patient with primary infertility who was suspected to have a hematosalpinx on ultrasonography and magnetic resonance imaging (MRI) but was found to have an appendiceal mucinous neoplasm on laparoscopy. Fertility preservation was offered to this patient. Appendiceal mucinous neoplasms should be considered in the differential diagnosis of patients in their reproductive years presenting with adnexal masses. Fertility preservation should be discussed with these patients, especially when gonadotoxic treatments are planned.

Immunoglobulin G4-related disease mimicking an appendiceal neoplasm: a case report.

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by chronic activation of the immune system and a tendency to form tumorous lesions. IgG4-RD is frequently characterized by the presence of tumor-like masses affecting multiple organs and is easily mistaken for a malignant neoplasm. However, IgG4-RD affecting the appendix is extremely rare, with only seven cases reported previously. We report the case of a woman in her early 60s who presented with insidious abdominal pain and radiological findings mimicking appendiceal neoplasms. After diagnosing appendiceal neoplasms, surgery was performed. The patient had a serum IgG4 concentration of <1.35 g/L, which did not satisfy one of the three revised comprehensive diagnostic criteria for IgG4-RD. A pathological examination was conducted, and the patient was diagnosed with appendiceal IgG4-RD. To the best of our knowledge, there have been no previously reported cases of IgG4-RD affecting the appendix in patients with low serum IgG4 concentrations. This report may prove beneficial for the future understanding of IgG4-RD and for the revision of diagnostic and treatment strategies.

Appendiceal neoplasms derived from appendiceal tip remnants following appendectomy: a report of two cases.

BACKGROUND: Neoplasms derived from remnant appendix are rarely described, with most cases arising from the appendiceal "stump". Here, we present two surgical cases of appendiceal neoplasms derived from appendiceal "tip" remnants. CASE PRESENTATION: The first patient was a 71-year-old man who had undergone laparoscopic appendectomy for acute appendicitis 12 years prior. During appendectomy, the appendiceal root was ligated, but the appendix was not completely removed due to severe inflammation. At the most recent presentation, computed tomography (CT) was performed to examine choledocholithiasis, which incidentally revealed a cystic lesion of approximately 90 mm adjacent to the cecum. A retrospective review revealed that the cystic lesion had increased in size over time, and laparoscopic ileocecal resection was performed. Pathology revealed no continuity from the appendiceal orifice to the cyst, and a diagnosis of low-grade appendiceal mucinous neoplasm (LAMN) was made from the appendiceal tip remnant. The patient was discharged without complications. The second patient was a 65-year-old man who had undergone surgery for peritonitis due to severe appendicitis 21 years prior. During this operation, the appendix could not be clearly identified due to severe inflammation; consequently, cecal resection was performed. He was referred to our department with a chief complaint of general fatigue and loss of appetite and a cystic lesion of approximately 85 mm close to the cecum that had increased over time. CT showed irregular wall thickening, and malignancy could not be ruled out; therefore, laparoscopic ileocecal resection with D3 lymph node dissection was performed. The pathological diagnosis revealed mucinous adenocarcinoma (TXN0M0) arising from the remnant appendiceal tip. The patient is undergoing follow-up without postoperative adjuvant chemotherapy, with no evidence of pseudomyxoma peritonei or cancer recurrence for 32 months postoperatively. CONCLUSIONS: If appendicitis-associated inflammation is sufficiently severe that accurate identification of the appendix is difficult, it may remain on the apical side of the appendix, even if the root of the appendix is ligated and removed. If the appendectomy is terminated incompletely, it is necessary to check for the presence of a residual appendix postoperatively and provide appropriate follow-up.

Superiority of 18F-FAPI-42 PET/CT in the detection of primary tumor and management of appendiceal neoplasm to 18F-FDG PET/CT and CE-CT.

BACKGROUND: In the present study, we investigated the value of 18F-fibroblast-activation protein inhibitor (FAPI) positron emission tomography/computed tomography (18F-FAPI-42 PET/CT) to preoperative evaluations of appendiceal neoplasms and management for patients. METHODS: This single-center retrospective clinical study, including 16 untreated and 6 treated patients, was performed from January 2022 to May 2023 at Southern Medical University Nanfang Hospital. Histopathologic examination and imaging follow-up served as the reference standard. 18F-FAPI-42 PET/CT was compared to 18F-fluorodeoxyglucose (18F-FDG) PET/CT and contrast-enhanced CT (CE-CT) in terms of maximal standardized uptake value (SUVmax), diagnostic efficacy and impact on treatment decisions. RESULTS: The accurate detection of primary tumors and peritoneal metastases were improved from 28.6% (4/14) and 50% (8/16) for CE-CT, and 43.8% (7/16) and 85.0% (17/20) for 18F-FDG PET/CT, to 87.5% (14/16) and 100% (20/20) for 18F-FAPI-42 PET/CT. Compared to 18F-FDG PET/CT, 18F-FAPI-42 PET/CT detected more regions infiltrated by peritoneal metastases (108 vs. 43), thus produced a higher peritoneal cancer index (PCI) score (median PCI: 12 vs. 5, P < 0.01). 18F-FAPI-42 PET/CT changed the intended treatment plans in 35.7% (5/14) of patients compared to CE-CT and 25% (4/16) of patients compared to 18F-FDG PET/CT but did not improve the management of patients with recurrent tumors. CONCLUSIONS: The present study revealed that 18F-FAPI-42 PET/CT can supplement CE-CT and 18F-FDG PET/CT to provide a more accurate detection of appendiceal neoplasms and improved treatment decision making for patients.

Retrospective analysis of the incidence of appendiceal neoplasm and malignancy in patients treated for suspected acute appendicitis.

BACKGROUND: Nonoperative management of uncomplicated appendicitis is currently being promoted as treatment option, albeit 0.7-2.5% of appendectomies performed due to suspected acute appendicitis show histologically malignant findings. The purpose of this study was to investigate the incidence of neoplasm and malignancy of the appendix in patients presenting with suspected acute appendicitis in real world setting. METHODS: This is a retrospective single-centre investigation of 457 patients undergoing appendectomy between the years 2017-2020. The patients' demographics, symptoms and diagnosis, intraoperative findings, and histopathological results were analysed. RESULTS: In 3.7% (n = 17) histological analysis revealed neoplasms or malignancies. Median age was 48 years (20-90 years), without sex predominance. Leukocytes (11.3 ± 3.7 G/l) and C-reactive protein (54.2 ± 69.0 mg/l) were elevated. Histological analysis revealed low-grade mucinous appendiceal neoplasia (n = 3), sessile serrated adenoma of the appendix (n = 3), neuroendocrine tumours (n = 7), appendiceal adenocarcinoma of intestinal type (n = 3), and goblet cell carcinoma (n = 1). Additional treatment varied between no treatment or follow-up due to early tumour stage (n = 4), follow-up care (n = 3), additional surgical treatment (n = 8), or best supportive care (n = 2). CONCLUSIONS: Preoperative diagnosis of appendiceal tumours is difficult. Nonoperative management of patients with acute, uncomplicated appendicitis potentially prevents the correct diagnosis of malignant appendiceal pathologies. Therefore, close follow-up or surgical removal of the appendix is mandatory.

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.

Neoplastic appendiceal mucinous lesions: a narrative review of the literature from an oncologist's perspective.

Appendiceal mucinous lesions' classification and nomenclature has been modified several times along the last decades, reflecting their great heterogeneity and making difficult to compare results and draw conclusions. Despite its nearby origin, appendiceal mucinous lesions have a distinctive behaviour compared to colorectal cancer, including their molecular and genetic markers. Due to their low frequency, their management is not well standardised. However, surgery is considered the cornerstone of treatment. Their indolent behaviour has encouraged surgeons to apply more aggressive treatments, such as cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC), that may extend overall survival. Chemotherapy is reserved for unresectable and/or disseminated disease and could play a role in the adjuvant and neoadjuvant setting. Pressurised intraperitoneal aerosol chemotherapy (PIPAC) is recently emerging as a possible alternative for treatment in advanced disease although its results in long-term survival are lacking Hereby, we review the available evidence in the management of appendiceal mucinous lesions, including localised and disseminated disease, with a special emphasis on the oncological perspective, focusing on the lights and shadows of the systemic treatments.

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.

¿Plastrón o tumor apendicular? / Plastron appendicitis or appendiceal tumor?

Un plastrón apendicular es una masa apendicular palpable que contiene el apéndice inflamado, vísceras adyacentes y el omento mayor, asociado a o no a la presencia de pus. El manejo del plastrón apendicular abscedado es controvertido. Cuando hay signos de sepsis asociados, la indicación es una intervención quirúrgica de urgencia, de lo contrario puede optarse por un tratamiento conservador. La utilización de drenaje percutáneo tiene una alta tasa de efectividad, aunque la tasa de neoplasias no detectadas presenta un porcentaje no despreciable, especialmente en los pacientes mayores de 40 años. El objetivo de esta presentación es comunicar una paciente de 65 años con diagnóstico presuntivo de plastrón apendicular abscedado quien luego del fracaso de los drenajes percutáneos fue sometida a una laparotomía exploratoria y hemicolectomía derecha. El diagnóstico histopatológico fue de adenocarcinoma mucinoso del apéndice. (AU)

A palpable inflammatory appendiceal mass may contain the inflamed appendix, adjacent viscera, and the greater omentum, associated or not with the presence of pus. The management of an inflammatory appendiceal mass is controversial. When there are associated signs of sepsis, the indication is emergency surgery, otherwise, you can opt for a conservative treatment. The use of percutaneous drainage has a high rate of effectiveness, although the rate of undetected neoplasia is not negligible, especially in patients older than 40 years. We present the case of a 65-year-old female patient with a presumptive diagnosis of an appendiceal mass with abscess, who underwent exploratory laparotomy and right hemicolectomy after percutaneous drainage failure. The histopathological diagnosis was mucinous adenocarcinoma of the appendix. (AU)

Appendiceal Mucinous Neoplasms: From Clinic to Pathology and Prognosis.

Appendiceal mucinous neoplasms have been classified differently over time causing confusion when comparing results between working groups in this field and establishing a prognosis of the disease. A historical perspective of the different classification systems of these tumors is essential for the understanding of the evolution of concepts and histopathological definitions that have led up to the present moment. We carried out a systematic review of the pathological classifications of appendiceal mucinous tumors and how they have included the new criteria resulting from clinical and pathological research. The latest classifications by PSOGI and AJCC 8th edition Cancer Staging have made a great effort to incorporate the new pathological descriptions and develop prognostic groups. The introduction of these new classification systems has posed the challenge of verifying how they adapt to our casuistry and which one defines best the prognosis of our patients. We reclassified our series of patients treated for mucinous appendiceal tumors with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy following the PSOGI and the AJCC 8th edition criteria and concluded that both classifications correspond well with the OS and DFS of these patients, with some advantage relative to the PSOGI classification due to a better histopathological description of the different groups.

Complete small intestinal obstruction due to band formation in low-grade appendiceal mucinous neoplasm: A rare case report and literature review.

INTRODUCTION: Intestinal obstruction due to external compression is a rare condition, and those caused by appendiceal neoplasms like low-grade appendiceal mucinous neoplasms are extremely rare. PRESENTATION OF CASE: A 67-year-old post-menopausal female, with no history of prior abdominal surgery, presented to the emergency room with constipation for 2 days, and peri-umbilical pain and non-projectile bilious vomiting for 19 h. There was mild abdominal distension and diffuse tenderness. After ultrasonography and Computed Tomography (CT) of the abdomen and pelvis, a provisional diagnosis of complete small bowel obstruction secondary to perforated mucinous neoplasm of the appendix was made. An emergency exploratory laparotomy was performed followed by ileo-cecal resection and ileocolic anastomosis. Intraoperative findings revealed bands extending from the appendix to the ileum forming a closed loop with gangrenous spots in the distal ileum and ascitic fluid with mucin. Later, histopathological examination findings were consistent with low-grade appendiceal mucinous neoplasm (LAMN). DISCUSSION: We reviewed three cases of intestinal obstruction, caused by compression from a LAMN, including the presented case. Preoperative diagnosis of the cause of small intestinal obstruction on CT is sometimes challenging. Hence, in patients with intestinal obstruction with a transition point in the right lower quadrant of the abdomen on CT, a high index of suspicion for an appendiceal etiology is required. CONCLUSION: LAMN with an associated band should be considered as one of the differential diagnoses in the patient presenting with symptoms of complete small intestinal obstruction without prior abdominal surgery.

Appendiceal neoplasms-A practical guide.

Appendiceal neoplasms (ANs) are a diverse group of pathologies that range from benign to malignant with widely varying prognoses. This article serves as an overview of the practical approach to evaluating and managing a patient with AN by reviewing the current literature and guidelines to provide a framework for the management of these nuanced pathologies.

Analysis of surgical treatment of appendix neuroendocrine neoplasms-17 years of single-center experience.

BACKGROUND/AIM: This study investigated the clinicopathological characteristics and treatment of appendix neuroendocrine neoplasms in appendectomy specimens of our center. MATERIALS AND METHODS: The clinicopathological data, including age, sex, preoperative clinical manifestation, surgical method, and histopathological examination results of 11 patients with appendix neuroendocrine neoplasms confirmed by surgery and pathology between November 2005 and January 2023, were retrospectively analyzed. RESULTS: In the histopathological examination of 7277 appendectomy specimens, 11 cases (0.2%) had appendix neuroendocrine neoplasms. Among the 11 patients, 8(72.7%) were males, and 3(27.3%) were females, with an average age of 48.1 years. All patients underwent emergency surgery. A total of 9 patients underwent open appendectomy, including 1 patient who underwent second-stage simple right hemicolectomy after an appendectomy, and two who underwent laparoscopic appendectomy. All 11 patients were followed up for a period of 1 to 17 years. All patients survived without any indication of tumor recurrence. CONCLUSION: Appendiceal neuroendocrine neoplasms are low-grade malignant tumors originating from neuroendocrine cells. They are rarely seen in clinical practice and are often treated based on acute and chronic appendicitis symptoms. These tumors are challenging to diagnose before surgery due to the lack of specificity in clinical manifestations and auxiliary examinations. The diagnosis generally depends on postoperative pathology and immunohistochemistry. Despite the diagnostic challenges, these tumors have a favorable prognosis.

Goblet cell adenocarcinoma of the appendix: A case report of three cases.

INTRODUCTION AND IMPORTANCE: Appendiceal goblet cell adenocarcinoma is in 0.3-0.9 % of appendectomy specimens. There is still controversy regarding whether surgery with dissection or additional resection is necessary for goblet cell adenocarcinoma and whether adjuvant chemotherapy is practical. We present three cases of goblet cell adenocarcinomas. CASE PRESENTATION: Case 1: A 30-year-old woman was diagnosed with appendicitis and underwent appendicectomy. Histopathological evaluation revealed a malignant neoplasm with goblet-like cells and tumour infiltration into the subserosa. The patient underwent laparoscopic ileocecal resection, and the main lymph nodes at the root of the feeding vessels were removed. Case 2: A 50-year-old man was diagnosed with appendicitis and underwent appendicectomy. Histopathological evaluation revealed a malignant neoplasm with goblet-like cells; malignant cells were found at the surgical resection margins. The patient underwent laparoscopic ileocolic resection. Case 3: A 60-year-old man undergoing treatment for malignant melanoma. He was diagnosed with appendicitis associated with an appendiceal tumour, and emergency laparoscopic caecal resection was performed and diagnosed as goblet cell adenocarcinoma. We decided to prioritize treatment for malignant melanoma, and the patient is under follow-up for goblet cell adenocarcinoma and no metastasis was detected. CLINICAL DISCUSSION: We performed additional resection in two case of goblet cell adenocarcinoma. Diagnosing appendiceal goblet cell adenocarcinoma is difficult, and the prognosis of patients with positive lymph nodes is poor. Surgical treatment should be considered for the advanced stages of this disease. CONCLUSION: Goblet cell adenocarcinoma, diagnosed after appendectomy, additional resection including lymph node dissection may provide a long-term prognosis.

Incarcerated Amyand Hernia Associated With Acute Appendicitis and Incidental Finding of Serrated Adenoma.

BACKGROUND: Amyand hernias are rare as they represent 0.5% of all hernias. An Amyand hernia that is discovered due to acute appendicitis is even rarer, accounting for approximately 0.11% of cases. Furthermore, appendiceal neoplasms are infrequently encountered in only 0.7-1.7% of appendectomy specimens. PURPOSE: This paper presents the case of an 85 year-old man presenting with acute appendicitis located within an amyand hernia as well as a serrated adenoma noted on final pathology. CONCLUSIONS: An Amyand hernia is a rare diagnosis. We proceeded with laparoscopic appendectomy and interval inguinal hernia repair. Pathology should be reviewed for all patients and proper follow up ensured for all incidental findings.

Appendiceal goblet cell carcinoma has marginal advantages from perioperative chemotherapy: a population-based study with an entropy balancing analysis.

PURPOSE: The aim is to clarify the use of perioperative chemotherapy in resectable goblet cell carcinoma (GCC). METHODS: A retrospective study was carried out based on the Surveillance, Epidemiology, and End Results study. The population was divided: into patients who received only radical surgery (group A) and those who received radical surgery plus chemotherapy (group B). An entropy balancing was carried out to correct the imbalance between the two groups. Two models were generated. Model 1 contained only high-risk patients: group B and a "virtual" group A with similar characteristics. Model 2 included only low-risk patients: group A and "virtual" group B with identical attributes. The efficacy of entropy balancing was evaluated with the d value. The overall survival was compared and reported with Hazard Ratio (HR) within a confidence interval of 95% (95 CI). RESULTS: The groups A and B were imbalanced for tumor size (d = 0.392), T (d = 1.128), N (d = 1.340), M (d = 1.456), mean number of positive lymph nodes (d = 0.907), and LNR (d = 0.889). Before the balancing, the risk of death was higher in group B than in A (4.3; 2.5 to 7.4). After reweighting, all large differences were eliminated (d < 0.200). In high-risk patients, the risk of death was higher in patients who underwent surgery alone than those who received perioperative chemotherapy (HR 0.5; 0.2 to 1.3) without statistical significance (p = 0.187). In low-risk patients, the risk of death was similar (HR 1.1; 0.3 to 3.3). CONCLUSION: Perioperative chemotherapy could provide some marginal advantages to high-risk patients.

Comparing Survival Outcomes and Impact of EPIC in Patients Undergoing CRS/HIPEC for Mucinous Appendiceal Neoplasm.

BACKGROUND/AIM: This study sought to investigate the difference in survival outcomes in patients with complete cytoreduction (CC)-0 or CC-1 mucinous appendiceal cancer undergoing cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC). It also investigated what effect early postoperative intraperitoneal chemotherapy (EPIC) may have on survival based on CC score and histology. PATIENTS AND METHODS: This was a retrospective single centre study of patients that underwent CRS/HIPEC +/- EPIC for mucinous appendiceal neoplasms from June 2003 to February 2022. RESULTS: A total of 545 patients were identified. Although there was a survival difference between CC-0 and CC-1 on univariate analyses, this was not statistically significant on multivariate analysis. Histology, peritoneal cancer index, and EPIC status were demonstrated to be independent factors that affected overall survival (OS) on multivariate analysis. Patients with CC-1 that received EPIC had significantly improved OS (mean OS 14 years) when compared to patients that did not receive EPIC (mean OS 6 years). In CC-1, OS was significantly improved in patients that received EPIC in both low-grade (p<0.001) and high-grade (p=0.012) disease. OS for patients that received EPIC at 1, 5, and 10 years was 95%, 80%, and 59%, respectively. OS for patients that did not receive EPIC at 1, 5, and 10 years was 84%, 49%, and 30%, respectively. CONCLUSION: There was no difference in OS between CC-0 and CC-1. The implementation of EPIC in patients with CC-1 significantly improved OS in both low-grade and high-grade disease and thus we recommend its addition in CC-1 disease to achieve optimal survival outcome.

Prognostic impact of number of examined lymph nodes on survival of patients with appendiceal neuroendocrine tumors.

BACKGROUND: The prognosis of patients with appendiceal neuroendocrine tumors (ANETs) is related to lymph node (LN) metastasis and other factors. However, it is unclear how the number of examined LNs (ELNs) impact on survival. AIM: To determine the factors affecting the cancer-specific survival (CSS) of patients with ANET and to evaluate the impact of the number of ELNs on survival. METHODS: A total of 4583 ANET patients were analyzed in the Surveillance, Epidemiology, and End Results database. Univariate survival analysis was used to identify factors related to survival and the optimal number of ELNs and lymph node ratio (LNR) were determined by the Kaplan-Meier method. The survival difference was determined by CSS. RESULTS: Except for sex, the other factors, such as age, year, race, grade, histological type, stage, tumor size, ELNs, LNR, and surgery type, were associated with prognosis. The 3-, 5-, and 10-year CSS rates of ANET patients were 91.2%, 87.5, and 81.7%, respectively (median follow-up period of 31 mo and range of 0-499 mo). There was no survival difference between the two surgery types, namely, local resection and colectomy or greater, in both stratifications of tumor size ≥ 2 cm (P = 0.523) and < 2 cm (P = 0.068). In contrast to patients with a tumor size < 2 cm, those with a tumor size ≥ 2 cm were more likely to have LN metastasis (χ 2 = 378.16, P < 0.001). The optimal number of ELNs was more than 11, 7, and 18 for all patients, node-negative patients, and node-positive patients, respectively. CSS rates of patients with a larger number of ELNs were significantly improved (≤ 10 vs ≥ 11, χ 2 = 20.303, P < 0.001; ≤ 6 vs ≥ 7, χ 2 = 11.569, P < 0.001; ≤ 17 vs ≥ 18, χ 2 = 21.990, P < 0.001; respectively). ANET patients with an LNR value ≤ 0.16 were more likely to have better survival than those with values of 0.17-0.48 (χ 2 = 48.243, P < 0.001) and 0.49-1 (χ 2 = 168.485, P < 0.001). CONCLUSION: ANET ≥ 2 cm are more likely to develop LN metastasis. At least 11 ELNs are required to better evaluate the prognosis. For patients with positive LN metastasis, 18 or more LNs need to be detected and lower LNR values (LNR ≤ 0.16) indicate a better survival prognosis.

Incidental Appendiceal Tumors During Appendectomy: A Nineteen-Year Retrospective Review at a Municipal Hospital.

Non-operative management of appendicitis (NOMA) has recently gained popularity, but a concern is that NOMA might miss appendiceal neoplasms. We conducted a retrospective review of 1694 appendectomies done for acute appendicitis at our institution between January 2001 and December 2019 to study the incidence and distribution of appendiceal tumors. We identified 24 appendiceal neoplasms (1.43%), including 9 Low Grade Appendiceal Mucinous Neoplasms (LAMNs), 6 neuroendocrine tumors (NETs), 6 mucoceles, and one each of adenocarcinoma, endometrioma, and neurofibroma. Tumor occurrence had two age peaks, with LAMNs prominent in the 5th and 6th decades of life and NETs in the 2nd and 3rd decades. All patients under age 40 had benign disease. Presence of appendicoliths was independent of the presence of neoplasms. All cases were managed per National Comprehensive Cancer Network (NCCN) guidelines, with twenty cases cured by appendectomy alone. Given these, we conclude that NOMA is safe for patients under 40.