The American Society of Colon and Rectal Surgeons, Clinical Practice Guidelines for the Management of Appendiceal Neoplasms

Utility of Left Lateral Liver Lobectomy in Removing Retrohepatic Lesions During Cytoreductive Surgery for Low-Grade Mucinous Carcinoma Peritonei

BACKGROUND

Complete cytoreduction (CC) during cytoreductive surgery (CRS) is essential for favorable outcomes in appendix neoplasms.1-5 However, achieving CC is particularly challenging and may require non-trivial maneuvers when the tumor grows in the left retrohepatic space and along the ligamentum venosum (LV).6-8 MATERIALS AND METHODS: This multimedia article features a step-by-step video of CRS with left lateral liver lobectomy (LLLL) in a patient with a low-grade appendiceal mucinous neoplasm (LAMN) and extensive peritoneal dissemination. After initial systemic chemotherapy resulted in toxicity and no disease response, the patient sought CRS and hyperthermic intraperitoneal chemotherapy (HIPEC) at our center.

RESULTS

The preoperative PCI was 34.9 Surgery started with greater omentectomy, left diaphragmatic peritonectomy, and splenectomy. During right diaphragmatic peritonectomy and porta hepatis dissection, we found peri- and retrohepatic implants extending to the left hepatic vein. To remove these difficult-to-reach lesions completely and safely, we performed LLLL using a "predissected" plane along LV. We then resected segment 1 due to bulky disease between it and inferior vena cava (IVC), which provided a direct view of the retrohepatic IVC, allowing for safe tumor removal. After completing CRS in other areas (CC-0), a 90-min HIPEC perfusion (mitomycin-C) was performed.9 The patient had no major complications.10 At 24 months post-CRS/HIPEC, he remained symptom- and disease-free.

CONCLUSIONS

Removing lesions around the left liver and segment 1 is challenging yet essential to ensure CC in LAMN. While not a routine maneuver, in such cases, LLLL can be utilized to access retrohepatic lesions safely and expeditiously, allowing for their removal.

A standardized surgical approach to appendiceal orifice tumors: a case report

The optimal management of appendiceal orifice (AO) tumors remains a topic of debate due to their anatomical complexity and the absence of a standardized surgical approach. This case report describes the successful treatment of an incompletely resected sessile serrated lesion at the AO in a 47-year-old female using a multidisciplinary strategy. Preoperative imaging, gastroenterology consultation, and intraoperative specimen evaluation guided a laparoscopic appendectomy with cecal cuff resection, achieving complete tumor removal with minimal morbidity. This approach preserved ileocecal valve function and ensured accurate pathological assessment. This case highlights key considerations, including the importance of avoiding ileocecal valve compromise and ensuring polyp retrieval for definitive pathological assessment. We propose appendectomy with cecal cuff resection as a standardized, effective technique to reduce treatment variability and mitigate incomplete resection risks in AO tumors.

A scoping review of postoperative surveillance strategies for localized, low-grade appendiceal mucinous neoplasms

INTRODUCTION

There is a paucity of data to support surveillance protocols for localized, low-grade appendiceal mucinous neoplasms (LAMNs) after resection.

METHODS

A search strategy was developed to identify postoperative surveillance strategies for LAMNs, in the context of rates of recurrence and disease-free survival, and applied to four literature databases. Resultant citations were subject to screening in duplicate, in three stages: title, abstract, and full-text. Data was extracted from the final set of included articles and subject to descriptive statistics.

RESULTS

A total of 16 articles, representing 1218 patients, were included. The duration of surveillance ranged from 0.1 to 294 months, and the mode surveillance interval was three months. The most common surveillance method was imaging (n ​= ​610 patients, 48.7 ​%). Thirty one patients had disease recurrence (2.7 ​%). Time to recurrence ranged from 2.5 to 68 months, and the range of five-year survival was 93.5-95.2 ​% among five studies.

DISCUSSION

In the absence of strong evidence to suggest that surveillance confers a survival benefit for patients with localized LAMNs after resection, decisions about surveillance should be patient-oriented.

Outcomes of laparoscopic single-incision caecal pole resection for low-grade appendiceal mucinous neoplasm

INTRODUCTION

Low-grade appendiceal mucinous neoplasm (LAMN) is a rare disease, and its clinical course varies from an incidental finding without symptoms to pseudomyxoma peritonei. Furthermore, there are few established treatment guidelines. This study was designed to confirm the outcomes in patients diagnosed with LAMN who underwent single-incision laparoscopic caecal pole resection.

PATIENTS AND METHODS

This study was conducted on pathologically confirmed LAMNs from patients who underwent surgery at a single centre, a tertiary institution, from July 2016 to August 2022. Patients diagnosed with LAMN as a result of biopsy were included. All surgeries were performed with single-incision laparoscopic caecal pole resection by a single surgeon.

RESULTS

A total of 70 patients were included. The median age was 65.5 years and 36 (51.4%) patients were female. The baseline carcinoembryonic antigen (CEA) was 8.08 ng/mL (0.76-148.11). The mean maximum diameter was 29.4 mm (7-70) and calcification was seen in 22 cases on pre-operative computed tomography (CT). As a result of histological examination, all patients were marginally negative. The larger the tumour size, the higher the CEA was ( P = 0.011), and it was often accompanied by calcification ( P = 0.021). In addition, tumour size and CEA showed a positive partial correlation with each other ( r = 0.318, P = 0.018). The overall median follow-up period was 22.7 months (2-60). One case had suspected of recurrence on CT scan performed at 33 months following the surgery, but there were no related symptoms.

CONCLUSION

Single-port laparoscopic caecal pole resection without margin involvement in LAMN was safe and feasible, and showed a favourable long-term outcome.

Appendectomy followed by two-stage right-sided colectomy with lymph node dissection for appendiceal cancer and risk factors for peritoneal recurrence: a single high-volume cancer center study in Japan

PURPOSE

Few studies have evaluated whether the timing of colectomy affects the prognosis of appendiceal cancer. This study compared long-term outcomes and recurrence patterns between initial appendectomy followed by two-stage colectomy and one-stage colectomy for appendiceal cancer.

METHODS

We retrospectively evaluated 65 patients who underwent 2-stage (n = 17) or 1-stage (n = 48) right-sided colectomy with lymph node dissection for stage 0-III appendiceal cancer between August 2005 and December 2022. The recurrence types and risk factors were compared.

RESULTS

The 2-stage colectomy group had a more advanced disease stage than the 1-stage group (stage III cases: 29.4% vs. 14.6%, P = 0.03). The 5-year overall recurrence rates were similar between the groups (29.4% vs. 19.2%, P = 0.39). All peritoneal recurrence cases (n = 9) had pT3 or T4 depth. Among pT3 and T4 cases (n = 46), the peritoneal recurrence rates did not differ significantly (31.2% vs. 13.8%, P = 0.17). A multivariate analysis identified preoperative serum CA19-9 level of > 37 ng/mL (hazard ratio [HR], 35.4; 95% confidence interval [CI], 3.08-406.8; P = 0.004) and lymph node metastasis (HR, 42.6; 95% CI, 9.90-183.6; P < 0.001) as independent risk factors for peritoneal recurrence.

CONCLUSIONS

Serum CA19-9 levels and lymph node metastasis are risk factors for peritoneal recurrence. The effect of colectomy timing on recurrence was not definitive.

Surveillance of low-grade appendiceal mucinous neoplasms for progression to pseudomyxoma peritonei: Results from a structured surveillance programme

AIM

Low-grade appendiceal mucinous neoplasm (LAMN) of the appendix is a rare tumour that can progress to pseudomyxoma peritonei (PMP). There is a lack of standardization of surveillance following resection of LAMN as the progression rate to PMP is unclear. The aim of this study was to evaluate the rate of progression following resection of LAMN to PMP in a structured surveillance programme.

METHOD

Data for all patients referred for LAMN surveillance from 2013 to 2021 were retrospectively collected. The surveillance regime consisted of annual CT and tumour markers for a 5-year period. Patients who progressed to PMP were identified.

RESULTS

Of the patients enrolled in surveillance following appendicectomy and LAMN diagnosis (65.1% female, median age 56 years), 83 had completed at least 1 year of surveillance (median follow-up 24 months). Of these, 6% (n = 5) showed disease progression during follow-up. The median time to progression was 23 months. Survival analysis revealed no statistically significant difference in progression with regards to T staging (p = 0.39), margin positivity (p = 0.11) or appendiceal perforation (p = 0.26). No patients with Tis disease developed PMP. A statistically significant difference in progression was seen in patients with M1b staging (p = 0.021) and in those with mucin beyond the right iliac fossa at diagnosis (p = 0.04).

CONCLUSION

The observed progression rate justifies the necessity of postappendicectomy surveillance in patients with LAMN, with the risk of progression being highest within the first 3 years of diagnosis. The described surveillance programme allows for early detection of subclinical progression to PMP.

Mucinous adenocarcinoma of the appendix presenting as acute appendicitis: a case report

Mucinous adenocarcinoma of the appendix (MAA) is a rare primary malignancy with an incidence of 0.01-0.2% and often presents as acute appendicitis. We present a case of a 61-year-old male who initially presented with right iliac fossa pain, worsening over 3 days, accompanied by appetite loss but no other symptoms. The patient's history included a splenectomy and epilepsy. Physical examination and computed tomography scan suggested a picture of acute appendicitis. He underwent an emergency laparoscopic appendectomy that was converted to open right hemicolectomy due to the mass's adherence to the cecum. The mass, at the cecum, originating from the appendix, measured 10 × 7 × 7 cm. Pathology confirmed a moderately differentiated MAA. Accurate diagnosis requires a combination of imaging and histopathology. The patient recovered well and was discharged on Day 6 postoperatively. We aim to highlight the importance of distinguishing MAA from acute appendicitis and the need for careful preoperative evaluation.

Mucocele of the appendix: our experience in treatment of rare pathologies

A mucocele of the appendix is a cystic formation of the appendix, the lumen of which is filled with mucin of varying consistency. There are benign and malignant forms of the disease. Its pathogenesis varies depending on the etiology and has not yet been fully studied. The clinical picture of this disease is nonspecific and there are difficulties in preoperative diagnosis. The purpose of the study is to present a rare clinical case of mucocele of the appendix, as well as literature data on this pathology. Successful treatment of a patient with appendix mucocele, an atypical location of the tumor was demonstrated. Based on the results of intraoperative express biopsy, as well as postoperative pathomorphological examination, surgical intervention was carried out to the required extent and with a favorable prognosis for the patient’s future life. Choosing the right method of surgical treatment allows you to avoid dangerous complications, such as the development of mucinous cystadenocarcinoma and pseudomyxoma peritonei. When performing surgery, it is necessary to be guided by the principles of safety from the patient’s point of view and not be afraid of performing access conversion.

Prognostic analysis of appendectomy versus right hemicolectomy for T1 appendiceal adenocarcinoma: a multicenter retrospective analysis

BACKGROUND AND AIM

Appendiceal adenocarcinoma, an exceedingly rare malignancy, sparks debate on the optimal surgical approach-appendectomy or right hemicolectomy-for early-stage cases. This study aims to investigate the impact of these two surgical methods on the survival prognosis of patients with early appendiceal adenocarcinoma.

METHOD

Utilizing a multicenter medical database, we gathered data from 168 patients diagnosed with T1 stage appendiceal adenocarcinoma admitted between January 2008 and January 2015. This study aims to compare the impact of different treatment modalities on the prognosis of appendiceal adenocarcinoma in these two groups.

RESULT

In patients diagnosed with T1 appendiceal adenocarcinoma, the survival prognosis was not significantly improved with right hemicolectomy compared to appendectomy. Out of one hundred twenty-seven patients undergoing right colon resection, only three exhibited lymphatic metastasis, resulting in a rate of 2.3%.

CONCLUSION

Simple appendectomy can fulfill the objective of achieving radical tumor resection, rendering right hemicolectomy unnecessary.

Who should get a right colectomy in low-grade appendiceal adenocarcinomas? Association of lymphovascular invasion and nodal metastases

BACKGROUND

There is variation in the probability of nodal metastases from low-grade appendiceal adenocarcinomas, and the role of right colectomy is unclear. We aimed to define the prevalence and utility of lymphovascular invasion in predicting the risk of nodal metastases to help stratify patients who may benefit from right hemicolectomy.

METHODS

Patients with nonmetastatic low-grade appendiceal adenocarcinomas were identified from the National Cancer Database (2010-2017). The primary outcome was probability of nodal metastases. Logistic regression was used to identify independent predictors of nodal metastases. A 4-tier risk model-the COH Composite Score-was calculated by assigning 1 point each for a high-risk feature (lymphovascular invasion, T3/T4 T stage, or nonmucinous histology). Survival analysis was performed using the Kaplan-Meier method. Multivariate Cox regression analysis was used to identify independent predictors of survival.

RESULTS

A total of 1,303 patients with nonmetastatic low-grade appendiceal adenocarcinomas (64.2% mucinous) were identified. Of the 1,133 patients with known lymphovascular invasion status, 78 (6.9%) were lymphovascular invasion positive. In multivariate analysis, lymphovascular invasion was independently associated with nodal metastases (odds ratio, 8.68; P < .001). Overall accuracy of lymphovascular invasion in predicting nodal metastases was 86%. The COH Composite Score stratified patients in 4 categories with increasing risk of nodal metastases and incrementally worse survival. For patients with the COH Composite Score of 0 (12%), the nodal metastasis rate was 3.1%, and a right hemicolectomy in this group did not improve survival.

CONCLUSION

The presence of lymphovascular invasion is strongly predictive of nodal metastases. Lymphovascular invasion as part of the COH Composite Score may help guide the extent of surgery in low-grade appendiceal adenocarcinomas.

Well-differentiated neuroendocrine tumors of the appendix: Diagnosis, differentials, and disease progression

Well-differentiated neuroendocrine tumors are the most common neoplasm of the appendix. They are graded and staged using World Health Organization and American Joint Committee on Cancer criteria, respectively. They may be invisible grossly or form rounded yellow nodules, sometimes in the appendiceal tip. They show classic neuroendocrine tumor features microscopically, forming nests and cords of monotonous cells with salt-and-pepper chromatin and amphophilic cytoplasm. They are positive for neuroendocrine markers by immunohistochemistry, but their molecular characteristics are not well defined. pT-category staging relies primarily on tumor size, though higher-stage cases may involve the subserosa or mesoappendix. Few entities enter the differential diagnosis, but lesions such as goblet cell adenocarcinoma, poorly differentiated neuroendocrine carcinoma, and mixed neuroendocrine-non-neuroendocrine neoplasm may be considered. Appendiceal neuroendocrine tumors may metastasize to regional lymph nodes, but farther spread is rare. The most consistently proven risk factor for such spread is tumor size, though different studies have proposed different cutoffs. Other potential risk factors include lymphovascular invasion and margin positivity. Tumors smaller than 1 cm can be treated by appendectomy, while hemicolectomy is recommended for tumors larger than 2 cm. Proper treatment for cases measuring 1-2 cm remains a matter of debate.

Appendiceal Mucocele Presenting as a Cecal Bulge on Surveillance Colonoscopy

Appendiceal mucoceles are rare tumors with diverse presentations and clinical implications. Generally, mucoceles are discovered on imaging or intraoperatively, but, rarely, can be found on colonoscopy. Appendectomy is the recommended next step in management, followed by subsequent treatment according to guidelines dictated by pathology findings. We present the case of a 52-year-old female undergoing routine colonoscopy screening who had incidental findings of a cecal bulge at the appendiceal orifice. The patient was entirely asymptomatic with an unremarkable medical history. Further workup suggested appendiceal mucocele and she was referred to surgery. After an appendectomy, pathology confirmed simple appendiceal mucocele. The patient made a full recovery and continued routine colonoscopy screening. This case demonstrates the variance in the clinical presentation of appendiceal mucocele and the possibility of discovery on routine screening colonoscopy.

Pseudomyxoma peritonei peritonitis

Pseudomyxoma peritonei (PMP) is a rare neoplastic condition characterised by gelatinous ascites, which generally arise from mucin-producing appendiceal tumours. Presentation is variable but requires prompt recognition to ensure appropriate specialist management due to risk of malignancy.A male in his 40s presented with a 1-day history of sudden onset, non-migratory abdominal pain, worse in the right iliac fossa. He had no significant medical history nor known drug allergies. Examination revealed right iliac fossa peritonism and blood tests revealed raised inflammatory markers. CT scan showed a right-sided abdominal collection. Intraoperatively, a diagnostic laparoscopy was performed, which revealed extensive mucin in the abdominal cavity. This was washed out and a laparoscopic appendectomy was performed; histopathology confirmed PMP from the ruptured appendix.

Appendiceal goblet cell adenocarcinoma with perineural invasion extending into the ileocecal lesion

BACKGROUND

Appendiceal goblet cell adenocarcinoma (GCA) is a rare subtype of primary appendiceal adenocarcinoma with an incidence of 1-5 per 10,000,000 people per year. Appendiceal tumors are often diagnosed after appendectomy for acute appendicitis. Notably, however, there is currently no standard treatment strategy for GCA, including additional resection. We report a case of appendiceal GCA with perineural extension into the cecum, in which ileal resection was considered effective.

CASE PRESENTATION

A 41-year-old man was diagnosed with acute appendicitis and underwent appendectomy. Histopathological findings revealed GCA (T3, Pn1). He was referred to our hospital for additional resection. Preoperative examination indicated a diagnosis of GCA cT3N0M0. Laparoscopic ileocecal resection and D3 lymph node dissection were performed 2 months after initial appendectomy. The patient had a good postoperative course and was discharged 8 days after surgery. Histopathological findings showed a GCA invading the cecum, despite an intact appendiceal stump, no lymph node metastasis, no vascular invasion, and no horizontal extension into the submucosa. Direct invasion of the tumor through the serosa was not observed, but perineural extension was conspicuous in the cecum, suggesting that the GCA extended into the cecum via perineural invasion. The resection margins were negative. The patient has survived free of recurrence for a year after ileocecal resection.

CONCLUSIONS

The current patient was diagnosed with appendiceal GCA following appendectomy for acute appendicitis. Despite intact of appendiceal stump and no evidence of lymph node or distant metastasis, he underwent laparoscopic ileocecal resection and D3 lymph node dissection 2 months after initial appendectomy, with a favorable outcome. Despite the detection of perineural invasion, the patient declined adjuvant therapy. This case suggests that extensive resection may be required in patients with appendiceal GCA, but the role of adjuvant therapy remains unclear.

Goblet cell carcinoid of the appendix: Six case reports

BACKGROUND

Goblet cell carcinoid (GCC) of the appendix is a rare tumor characterized by neuroendocrine and adenocarcinoma features. Accurate preoperative diagnosis is very difficult, with most patients complaining mainly of abdominal pain. Computed tomography shows swelling of the appendix, so diagnosis is usually made incidentally after appendectomy based on a preoperative diagnosis of appendicitis. Even if a patient undergoes preoperative colonoscopy, accurate endoscopic diagnosis is very difficult because GCC shows a submucosal growth pattern with invasion of the appendiceal wall.

CASE SUMMARY

Between 2017 and 2022, 6 patients with GCC were treated in our hospital. The presenting complaint for 5 of these 6 patients was abdominal pain. All 5 patients underwent appendectomy, including 4 for a preoperative diagnosis of appendicitis and the other for diagnosis and treatment of an appendiceal tumor. The sixth patient presented with vomiting and underwent ileocecal resection for GCC diagnosed from preoperative biopsy. Although 2 patients with GCC underwent colonoscopy, no neoplastic changes were identified. Two of the six patients showed lymph node metastasis on pathological examination. As of the last follow-up (median: 15 mo), all cases remained alive without recurrence.

CONCLUSION

As preoperative diagnosis of GCC is difficult, this possibility must be considered during surgical treatments for presumptive appendicitis.

What is the optimum post treatment surveillance imaging protocol for low-grade appendiceal mucinous neoplasms and pseudomyxoma peritoneii?

Appendiceal mucinous neoplasms are rare and can be associated with the development of disseminated peritoneal disease known as pseudomyxoma peritonei (PMP). Mucinous tumours identified on appendicectomy are therefore followed up to assess for recurrence and the development of PMP. In addition, individuals who initially present with PMP and are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are followed up to assess for recurrence. However, despite the concerted efforts of multiple expert groups, the optimal imaging follow-up protocol is yet to be established. The purpose of this article is to review the available evidence for imaging surveillance in these populations to identify the optimum post-resection imaging follow-up protocol.

Complicated Appendicitis Associated With Appendiceal Mucinous Neoplasm Within Amyand's Hernia in a Patient With Previous Hernia Repair: A Case Report and Literature Review

Amyand's hernia is defined as the presence of the appendix within an inguinal hernia sac, which is often associated with appendicitis. The association of an Amyand's hernia with an appendicular tumor has been reported in very few cases. This case report presents a 67-year-old female patient who came to the emergency department with symptoms indicative of a complicated inguinal hernia. Following surgical treatment, the diagnosis of Amyand's hernia with cecal perforation associated with an appendicular tumor was established in the context of a previous laparoscopic femoral hernia repair. The combination of these conditions has not been previously reported. The presentation of this case provides data on the clinical presentation, diagnosis, and treatment of this rare pathology that requires a high clinical suspicion to achieve a preoperative diagnosis.

Extent of Resection and Long-Term Outcomes for Appendiceal Adenocarcinoma: a SEER Database Analysis of Mucinous and non-Mucinous Histologies

BACKGROUND

Mucinous appendiceal adenocarcinomas (MAA) and non-mucinous appendiceal adenocarcinomas (NMAA) demonstrate differences in rates and patterns of recurrence, which may inform the appropriate extent of surgical resection (i.e., appendectomy versus colectomy). The impact of extent of resection on disease-specific survival (DSS) for each histologic subtype was assessed.

PATIENTS AND METHODS

Patients with resected, non-metastatic MAA and NMAA were identified in the Surveillance, Epidemiology, and End Results database (2000-2020). Multivariable models were created to examine predictors of colectomy for each histologic subtype. DSS was calculated using Kaplan-Meier estimates and examined using Cox proportional hazards modeling.

RESULTS

Among 4674 patients (MAA: n = 1990, 42.6%; NMAA: n = 2684, 57.4%), the majority (67.8%) underwent colectomy. Among colectomy patients, the rate of nodal positivity increased with higher T-stage (MAA: T1: 4.6%, T2: 4.0%, T3: 17.1%, T4: 21.6%, p < 0.001; NMAA: T1: 6.8%, T2: 11.4%, T3: 25.6%, T4: 43.8%, p < 0.001) and higher tumor grade (MAA: well differentiated: 7.7%, moderately differentiated: 19.2%, and poorly differentiated: 31.3%; NMAA: well differentiated: 9.0%, moderately differentiated: 20.5%, and 44.4%; p < 0.001). Nodal positivity was more frequently observed in NMAA (27.6% versus 16.4%, p < 0.001). Utilization of colectomy was associated with improved DSS for NMAA patients with T2 (log rank p = 0.095) and T3 (log rank p = 0.018) tumors as well as moderately differentiated histology (log rank p = 0.006). Utilization of colectomy was not associated with improved DSS for MAA patients, which was confirmed in a multivariable model for T-stage, grade, and use of adjuvant chemotherapy [hazard ratio (HR) 1.00, 95% confidence interval (CI) 0.81-1.22].

CONCLUSIONS

Colectomy was associated with improved DSS for patients with NMAA but not MAA. Colectomy for MAA may not be required.

A Case of Low-Grade Appendiceal Mucinous Neoplasm: The Role of Preoperative Imaging and Surgical Technique in Achieving Favorable Outcomes

Appendiceal mucinous neoplasms may present without symptoms or with chronic pain in the right lower quadrant. This report describes a case of a 35-year-old woman who presented with chronic right lower quadrant pain and was found to have a low-grade appendiceal mucinous neoplasm (LAMN). Physical examination revealed localized tenderness in the right lower quadrant with no additional symptoms. Preoperative laboratory results were normal, and a CT scan revealed a cystic appendiceal lesion with an internal calcification, initially mistaken for a fecalith, which led to the decision for exploratory laparotomy. Intraoperative findings confirmed the presence of a cystic-like appendiceal lesion, and an open appendectomy was performed. Histopathological examination revealed a low-grade appendiceal mucinous neoplasm (LAMN) confined to the mucosa, without evidence of metastatic disease. The patient had an uneventful recovery and required no additional treatment. This case highlights that surgical intervention with proper technique for confined appendiceal neoplasms, combined with effective preoperative imaging and thorough histopathological examination, is crucial for diagnosis and effective management, ensuring favorable outcomes.

Visualizing the landscape of appendiceal tumor research after 2010: A bibliometric study

BACKGROUND

Despite the rarity of appendiceal tumors, research in this field has intensified, resulting in a growing number of studies and published papers. Surprisingly, no comprehensive bibliometric analysis has specifically addressed appendiceal tumors.

AIM

To offer a thorough analysis of the current landscape and future trends in appendiceal tumor research.

METHODS

In our bibliometric analysis studies, we explored the Web of Science Core Collection database. The bibliographic details of the chosen publications were automatically converted and analyzed using the bibliometric package in the R environment. Additionally, we employed VoSviewer to create cooperation network maps for countries, institutions, and authors, as well as clustering maps for keywords. Furthermore, CiteSpace, another software tool, was utilized to build dual-map overlays of journals and analyze references with citation bursts.

RESULTS

Our study included 780 English-language articles published after 2010. The number of related publications and citations has increased in the past decade. The United States leads in this area, but there is a need to improve cooperation and communication among countries and institutions. Co-occurrence analysis also revealed close collaboration among different authors. Annals of Surgical Oncology was the most influential journal in this field. Analysis of references with high co-citations and references with citation bursts, consistent with analysis of keywords and hotspots, indicated that current research primarily centers on the classification and management of appendiceal mucinous neoplasms and consequent pseudomyxoma peritonei. Despite the abundance of clinical studies, a greater number of in-depth basic research studies should be conducted.

CONCLUSION

Current research on appendiceal tumors focuses on classification and management of appendiceal mucinous neoplasms and pseudomyxoma peritonei. Enhanced collaboration and basic research are vital for further advancement.

Mucocele of the appendix: case report of a rare disease with changing diagnostic-therapeutic behavior

Mucinous appendicular neoplasms are a rare and heterogeneous group of tumors, whose treatment may vary based on histologic features and extent. We present a case of low-grade appendiceal mucinous neoplasm mimicking an acute appendicitis scenario. The patient underwent appendectomy along with resection of the caecal fundus. Choosing the correct treatment according to the case by following current guidelines is crucial to avoid under- or overtreatment.

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.

Analysis of causes and prognostic impact of tube occlusion during hyperthermic intraperitoneal chemotherapy for appendiceal pseudomyxoma peritonei

BACKGROUND

Appendiceal pseudomyxoma peritonei (PMP), a rare tumor from mucinous appendiceal origins, is treated with Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC). However, tubing blockages during HIPEC treatment pose a common challenge, impeding the smooth progression of therapy. Few studies to date have explored the incidence and risk factors of tube occlusion during HIPEC in patients with appendiceal PMP, as well as its adverse impact on postoperative complications.

METHODS

From October 2017 to June 2023, a total of 80 patients with appendiceal PMP undergoing combined CRS and HIPEC were included in this study. Tubing blockage events were strictly defined, with patients experiencing blockages during HIPEC treatment allocated to the study group, while those with unobstructed perfusion were assigned to the control group. A comparative analysis was conducted between the two groups regarding post-HIPEC health assessments and occurrence of complications. Risk factors for luminal occlusion during closed HIPEC procedures were identified through univariate and multivariate analysis of data from 303 HIPEC treatments.

RESULTS

Tubing blockages occurred in 41 patients (51.3%). The study group experienced prolonged gastrointestinal decompression time (4.1 ± 3.0 vs. 2.5 ± 1.7 days, P = 0.003) and prolonged time to bowel movement (6.1 ± 2.3 vs. 5.1 ± 1.8 days, P = 0.022) compared to the control group. There was no significant difference in the incidence of complications between the two groups. The 1-year survival rate postoperatively was 97%, and the 3-year survival rate was 81%, with no association found between tubing blockage and poorer survival. Additionally, In 303 instances of HIPEC treatment among these 80 patients, tube occlusion occurred in 89 cases (89/303, 29.4%). Multivariable logistic regression analysis revealed age, diabetes, hypertension, and pathology as independent risk factors for tube occlusion.

CONCLUSION

Tubing blockages are a common occurrence during HIPEC treatment, leading to prolonged postoperative gastrointestinal functional recovery time. When patients are elderly and have concomitant hypertension and diabetes, along with a histological type of low-grade mucinous tumor, the risk of tube occlusion increases. However, this study did not find a significant correlation between tubing blockage and the incidence of postoperative complications or overall patient survival.

A CT-based radiomics nomogram involving the cystic fluid area for differentiating appendiceal mucinous neoplasms from appendicitis with intraluminal fluid

OBJECTIVE

To develop and validate a radiomics nomogram based on computed tomography (CT) to distinguish appendiceal mucinous neoplasms (AMNs) from appendicitis with intraluminal fluid (AWIF).

METHOD

A total of 211 patients from two medical institutions were retrospectively analysed, of which 109 were pathologically confirmed as having appendicitis with concomitant CT signs of intraluminal fluid and 102 as having AMN. All patients were randomly assigned to a training (147 patients) or validation cohort (64 patients) at a 7:3 ratio. Radiomics features of the cystic fluid area of the appendiceal lesions were extracted from nonenhanced CT images using 3D Slicer software. Minimum redundancy maximum relevance and least absolute shrinkage and selection operator regression methods were employed to screen the radiomics features and develop a radiomics model. Combined radiomics nomogram and clinical-CT models were further developed based on the corresponding features selected after multivariate analysis. Lastly, receiver operating characteristic curves, and decision curve analysis (DCA) were used to assess the models' performances in the training and validation cohorts.

RESULTS

A total of 851 radiomics features were acquired from the nonenhanced CT images. Subsequently, a radiomics model consisting of eight selected features was developed. The combined radiomics nomogram model comprised rad-score, age, and mural calcification, while the clinical-CT model contained age and mural calcification. The combined model achieved area under the curves (AUCs) of 0.945 (95% confidence interval [CI]: 0.895, 0.976) and 0.933 (95% CI: 0.841, 0.980) in the training and validation cohorts, respectively, which were larger than those obtained by the radiomics (training cohort: AUC, 0.915 [95% CI: 0.865, 0.964]; validation cohort: AUC, 0.912 [95% CI: 0.843, 0.981]) and clinical-CT models (training cohort: AUC, 0.884 [95% CI: 0.820, 0.931]; validation cohort: AUC, 0.767 [95% CI: 0.644, 0.863]). Finally, DCA showed that the clinical utility of the combined model was superior to that of the clinical CT and radiomics models.

CONCLUSION

Our combined radiomics nomogram model constituting radiomics, clinical, and CT features exhibited good performance for differentiating AMN from AWIF, indicating its potential application in clinical decision-making.

Nodular image in the appendix observed on ultrasound: endometriosis or neuroendocrine neoplasia?

Objective

To evaluate the association between clinical and imaging with surgical and pathological findings in patients with suspected neuroendocrine tumor of appendix and/or appendix endometriosis.

Methods

Retrospective descriptive study conducted at the Teaching and Research Institute of Hospital Israelita Albert Einstein, in which medical records and databases of patients with suspected neuroendocrine tumor of appendix and/or endometriosis of appendix were analyzed by imaging.

Results

Twenty-eight patients were included, all of which had some type of appendix alteration on the ultrasound examination. The pathological outcome of the appendix found 25 (89.3%) lesions compatible with endometriosis and three (10.7%) neuroendocrine tumors. The clinical findings of imaging and surgery were compared with the result of pathological anatomy by means of relative frequency.

Conclusion

It was possible to observe a higher prevalence of appendix endometriosis when the patient presented more intense pain symptoms. The image observed on ultrasound obtained a high positive predictive value for appendicular endometriosis.

Surgical outcomes and predictors of overall survival of stage I-III appendiceal adenocarcinoma: Retrospective cohort analysis of the national cancer database

BACKGROUND

This study aimed to determine predictors of overall survival (OS) after surgical treatment of stage I-III appendiceal adenocarcinoma and compare the outcomes of partial colectomy and hemicolectomy.

METHODS

A retrospective analysis of the U.S. National Cancer Database (NCDB) including patients who underwent surgery for stage I-III appendiceal adenocarcinoma between 2005 and 2019 was conducted. A propensity-score matched analysis was undertaken to compare the outcomes of partial and hemicolectomy and multivariate analysis was performed to determine predictive factors of OS. The main outcome was OS and its independent predictors.

RESULTS

2607 patients (51.6 % male) with a mean age of 61.6 ± 13.9 years were included. 61.7 % of patients underwent hemicolectomy while 31.7 % underwent partial colectomy. After matching, partial colectomy, and hemicolectomy had similar OS (117.3 vs 117.2 months; p = 0.08), positive resection margins, short-term mortality, and 30-day readmission. The hemicolectomy group was associated with more examined lymph nodes and longer hospital stays. Older age (HR: 1.047, p < 0.0001), rural residence area (HR: 3.6, p = 0.025), higher Charlson score (HR: 1.6, p = 0.016), signet-ring cell carcinoma (HR: 2.37, p = 0.009), adjuvant systemic treatment (HR: 1.55, p = 0.015), positive surgical margins (HR: 1.83, p = 0.017), positive lymph nodes number (HR: 1.09, p < 0.0001), and examined lymph nodes number (HR: 0.962, p = 0.001) were independent predictors of OS.

CONCLUSIONS

Partial colectomy and hemicolectomy had similar OS and clinical outcomes. Older age, rural residence, higher Charlson score, signet-ring pathology, adjuvant systemic treatment, positive surgical margins, positive lymph node number, and examined lymph node number were independent predictors of OS.

Appendiceal mucinous neoplasm in adolescence: Diagnosis, management, and surveillance

This case report describes a 17-year-old patient with a low-grade appendiceal mucinous neoplasm. The patient presented with non-bloody diarrhea, abdominal pain, and weight loss. A colonoscopy revealed a cecal polypoid mass that required laparoscopic surgery. The residual appendix was dilated with myxoglobulosis and histopathology confirmed the diagnosis of a low-grade appendiceal mucinous neoplasm staged pT3Nx. The potential risk of pseudomyxoma peritonei is a serious complication of these tumors. Surveillance plans include computed tomography abdomen and pelvis, and tumor markers every 6 months for the next 2 years. This case highlights the importance of considering appendiceal malignancy in patients with abdominal pain and weight loss, despite the rarity of the disease. It also emphasizes the need for careful monitoring due to the possible complications associated with these tumors. Treatment and prognosis for appendiceal neoplasms depend on the histopathologic characteristics, tumor-nodes-metastasis stage, tumor grade, and presence of peritoneal disease.

Intraoperative predictors of appendiceal abnormalities in patients with mucinous ovarian neoplasms

OBJECTIVE

To evaluate intraoperative factors predicting appendiceal pathology during gynecologic oncology surgery for suspected mucinous ovarian neoplasms.

METHODS

We conducted a retrospective study on 225 patients with mucinous ovarian neoplasms who underwent surgery for an adnexal mass with concurrent appendectomy between 2000 and 2018. Regression analyses were used to evaluate intraoperative factors, such as frozen section of the ovarian mass and surgeon's impression of the appendix in predicting appendiceal pathology.

RESULTS

Most patients (77.8%) had a normal appendix on final pathology. Abnormal appendix cases (n = 26) included: metastasis from high-grade adenocarcinoma of the ovary (n = 1), neuroendocrine tumor of the appendix (n = 4), and low-grade appendiceal mucinous neoplasms (n = 26; 23 associated with a mucinous ovarian adenocarcinoma, 2 with a benign mucinous ovarian cystadenoma, and 1 with a borderline mucinous ovarian tumor). Combining normal intraoperative appearance of the appendix with benign or borderline frozen section yielded a negative predictive value of 85.1%, with 14.9% of patients being misclassified, and 6.0% having a neuroendocrine tumor or low-grade appendiceal neoplasm.

CONCLUSION

Benign or borderline frozen section of an ovarian mucinous neoplasm and normal appearing appendix have limited predictive value for appendiceal pathology. Appendectomy with removal of the mesoappendix should be considered in all cases of mucinous ovarian neoplasm, regardless of intraoperative findings.

Appendiceal Mucinous Neoplasms and Inflammatory Bowel Disease: Systematic Review of the Literature

There is no clear evidence on the prevalence and clinical presentation of appendiceal mucinous neoplasm (AMN) among patients with inflammatory bowel disease (IBD), so a systematic review was performed to investigate the diagnosis, management and treatment of AMN in these patients. PubMed, Medline, Scopus and the Cochrane Library were searched for articles published up to September 2023. Twenty-three studies reporting data about 34 AMN patients were included. UC patients had a median age of 52 years and a median length of disease of 10 years; CD patients had a median age of 40.5 years and a median length of disease of 5 years. A pre-operative diagnosis was achieved in 44% of patients. Most patients were symptomatic (82.6%) and showed moderate-severe disease activity (61%). Surgical procedures were performed: laparoscopic appendectomy, ileocecal resection, right hemicolectomy and colectomy/proctocolectomy. Of the patients, 73.5% were diagnosed with low-grade mucinous neoplasm (LAMN) and nine with adenocarcinoma. Synchronous colorectal dysplasia/carcinoma was present in 23.5% of patients. IBD patients with long-standing disease should be routinely screened, not only for colorectal cancer but also for AMN, during gastro-enterologic follow-up. Laparoscopic appendectomy of unruptured LAMN as well as right hemicolectomy of non-metastatic adenocarcinoma are safe procedures in IBD patients.

Treatment Variation and Long-Term Outcomes of Low-Grade Appendiceal Neoplasms

BACKGROUND

Heterogenous nomenclature describing appendiceal neoplasms has added to uncertainty around their appropriate treatment. Although a recent consensus has established the term low-grade appendiceal neoplasm (LAMN), we hypothesize that significant variation remains in the treatment of LAMNs.

METHODS

We retrospectively reviewed our prospectively maintained appendiceal registry, identifying patients with LAMNs from 2009 to 2019. We assessed variability in treatment, including whether patients underwent colectomy, spread of disease at presentation, and long-term outcomes.

RESULTS

Of 136 patients with LAMNs, 88 (35%) presented with localized disease and 48 (35%) with disseminated peritoneal disease. Median follow-up was 2.9 years (IQR 1.9-4.4), and 120 (88%) patients underwent pre-referral surgery. Among 26 pre-referral colectomy patients, 23 (88%) were performed for perceived oncologic need/nodal evaluation; no nodal metastases were identified. In patients with resected LAMNs without radiographic evidence of disseminated disease, 41 (47%) underwent second look diagnostic laparoscopy (DL) to evaluate for occult metastases. No peritoneal metastases were identified. Patients with disseminated disease were treated with cytoreductive surgery/heated intraperitoneal chemotherapy (CRS/HIPEC). For patients undergoing CRS/HIPEC, 5-year recurrence-free survival was 94% (95% CI 81-98%). For patients with localized disease, 5-year RFS was 98% (95% CI 85-99%).

CONCLUSIONS

Significant variation exists in treatment patterns for LAMNs, particularly prior to referral to a high-volume center. Patients frequently underwent colectomy without apparent oncologic benefit. In the current era of high-quality cross sectional imaging, routine use of DL has low yield and is not recommended. Recurrence in this population is rare, and low-intensity surveillance can be offered. Overall prognosis is excellent, even with peritoneal disease.

Role of colectomy in the management of appendiceal tumors: a retrospective cohort study

BACKGROUND

Appendiceal tumors represent a range of histologies that vary in behavior. Recommendations for treatment with appendectomy versus right hemicolectomy (RHC) for different tumor types are evolving and sometimes conflicting. This study sought to characterize variation in the United States around surgical treatment of major appendiceal tumor types over time and describe differences in outcomes based on procedure.

METHODS

Patients diagnosed with appendiceal goblet cell adenocarcinoma (GCA), mucinous adenocarcinoma, neuroendocrine neoplasm (NEN), or non-mucinous adenocarcinoma from 2004-2017 were identified in the National Cancer Database. Trends in RHC over time and predictors of RHC were identified. Surgical outcomes for each histologic type and stage were compared.

RESULTS

Of 18,216 patients, 11% had GCAs, 34% mucinous adenocarcinoma, 31% NENs, and 24% non-mucinous adenocarcinoma. Rate of RHC for NEN decreased from 68% in 2004 to 40% in 2017 (p = 0.008) but remained constant around 60-75% for other tumor types. Higher stage was associated with increased odds of RHC for all tumor types. RHC was associated with higher rate of unplanned readmission (5% vs. 3%, p < 0.001) and longer postoperative hospital stay (median 5 days vs. 3 days, p < 0.001). On risk-adjusted analysis, RHC was significantly associated with increased survival versus appendectomy for stage 2 disease of all tumor types (HRs 0.43 to 0.63) and for stage 1 non-mucinous adenocarcinoma (HR = 0.56).

CONCLUSIONS

Most patients with appendiceal tumors undergo RHC, which is associated with increased readmission, longer length of stay, and improved survival for stage 2 disease of all types. RHC should be offered selectively for appendiceal tumors.

Incidence trends and survival analysis of appendiceal tumors in the United States: Primarily changes in appendiceal neuroendocrine tumors

BACKGROUND

Appendiceal tumors are considered to be a relatively rare tumor of the gastrointestinal tract and the prognosis is unclear. This study comprehensively investigated trends in the epidemiology and survival of appendiceal tumors in the United States over the past approximately 20 years.

METHODS

Patients with pathologically confirmed appendiceal tumors from 2000 to 2017 were selected from the Surveillance, Epidemiology and End Results (SEER) database. Age-adjusted incidence rates were calculated by SEER*Stat 8.4.0. The Kaplan-Meier method was used to analyze survival and prognostic factors were investigated by a multivariate Cox proportional risk model.

RESULTS

Ultimately, 13,546 patients with appendiceal tumors between 2000 and 2017 were included. The annual incidence of colonic adenocarcinoma and mucinous adenocarcinoma remained relatively stable. Interestingly, the annual incidence of appendiceal neuroendocrine tumors (aNETs) increased significantly, from 0.03 to 0.90 per 100,000 person-years, with the most dramatic increase in the number of patients with localized disease. Patients with aNETs showed a significant improvement in survival between 2009-2017, compared to the period 2000-2008. Moreover, this improvement in survival over time was seen at all stages (localized, regional, distant) of aNETs. However, this improved survival over time was not seen in colonic and mucinous adenocarcinoma.

CONCLUSIONS

The incidence of appendiceal neoplasms has increased significantly over the past nearly two decades, which is mainly due to the increased incidence and significant migration to earlier stages in aNETs. We must note that despite the increased incidence of aNETs, survival rates have improved at different disease stages.

Incidence rate and histology of appendiceal neoplasms in complicated versus uncomplicated appendicitis: A meta-analysis and systematic review

INTRODUCTION

Studies evaluating the rate and histology of appendiceal neoplasms between complicated and uncomplicated appendicitis include a small number of patients. Therefore, we sought a meta-analysis and systematic review comparing the rates and types of appendiceal neoplasm between complicated and uncomplicated appendicitis.

METHODS

We included articles published from the time of inception of the datasets to September 30, 2022. The electronic databases included English publications in Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid EMBASE, and Scopus.

RESULTS

A total of 4962 patients with appendicitis enrolled in 4 comparative studies were included. The mean age was 43.55 years (16- 94), and half were male (51%). Based on intra-operative findings, 1394 (38%) had complicated appendicitis, and 3558 (62%) had uncomplicated appendicitis. The overall incidence rate of neoplasm was 1.98%. No significant difference was found in the incidence rate of appendiceal neoplasm between complicated (3.29%) and uncomplicated (1.49%) appendicitis (OR 0.44, 95% CI 0.16- 1.23; p < 0.087; I2 = 54.9%). The most common appendiceal neoplasms were Neuroendocrine Tumors (NET) (49.21%), Nonmucinous Adenocarcinoma (24.24%), Mixed Adeno-Neuroendocrine Tumor (MANEC) (11.40%), Mucinous Adenocarcinoma (4.44%). There was a significant difference between complicated and uncomplicated appendicitis in rates of adenocarcinoma (50% vs. 13%), NET (31% vs. 74%), MANEC (19% vs. 13%) (P < 0.001).

CONCLUSION

While there was no significant difference in the overall neoplasm rate between complicated and uncomplicated appendicitis, the NET rate was significantly higher in uncomplicated appendicitis. In comparison, the Adenocarcinoma rate was considerably higher in Complicated appendicitis. These findings emphasize the importance of evaluating risk factors for neoplasm when considering appendectomy in patients with appendicitis.

Does a Positive Appendiceal Resection Margin in Low-Grade Appendiceal Mucinous Neoplasms, Warrant Additional Surgery? Our Institution Experience and Literature Review

BACKGROUND

Management of low-grade appendiceal mucinous neoplasm (LAMN) with positive resection margin is controversial. Some guidelines recommend surgical reexcision, whereas others recommend a conservative approach. The purpose of our study was to determine whether involvement of the resection margin by LAMN is a risk factor for local recurrence requiring additional surgery.

DESIGN

This is a retrospective study (January 2000-December 2020) of uncomplicated LAMNs with neoplastic epithelium or dissecting mucin at the resection margin. For cases treated with additional surgery, the presence of residual tumor was evaluated. Clinical follow-up was attained in all cases. We also conducted a literature review.

RESULTS

The study investigated 98 patients. Eight with median age of 67 (range: 45-91) years had a LAMN involving the resection margin (8.2%). Five of eight LAMNs (62.5%) with neoplastic epithelium at the margin underwent surgery, and no residual neoplasm was identified. The other three cases were followed conservatively, and no patient developed recurrence (follow-up: 18-69 months with a mean of 45 months). In a review of the literature, we identified 52 LAMNs with positive margin. Although three cases had acellular mucin and one residual LAMN in the reexcision specimen (7.7%), neither of these four cases or any of the other 46 followed conservatively had recurrence of disease.

CONCLUSIONS

These data suggest that for patients with uncomplicated LAMN confined to the appendix, the involvement of the appendiceal margin does not necessary lead to recurrence of LAMN, and a conservative management is a reasonable alternative.

A national cancer database analysis of the clinicopathologic characteristics and outcomes of appendiceal malignant mesenchymal tumors

The present study aimed to assess the characteristics and outcomes of appendiceal malignant mesenchymal tumors. This was a retrospective case-series study of patients with appendiceal malignant mesenchymal tumors in the national cancer database (2005-2019). The main outcomes were overall survival (OS) and short-term mortality. 53 patients (40 GISTs and 13 sarcomas) were included. 92.6% of GIST patients had stage I disease and 76.9% of GISTs were ≤2 cm. Most appendiceal GISTs were treated with appendectomy or partial colectomy whereas half of patients with appendiceal sarcoma underwent hemicolectomy or subtotal colectomy. Only one short-term mortality was recorded in the sarcoma group. One-third of patients with sarcoma had positive surgical margins versus 5.1% of patients with GISTs. GIST patients had longer median OS (117.1 vs 54.8 months) than sarcoma patients.

Cancer-specific survival in non-mucinous appendiceal adenocarcinomas after local resection versus right hemicolectomy: A Surveillance, Epidemiology, and End Results database study

BACKGROUND

Adenocarcinomas of the appendix are rare cancers for which no National Comprehensive Cancer Network guidelines exist, and for patients who undergo resection with curative intent, there is a paucity of data on prognostic factors affecting long-term cancer-specific survival. We aimed to compare the cancer-specific survival outcomes in adult patients with appendiceal non-mucinous adenocarcinoma undergoing either local resection versus right hemicolectomy.

METHODS

This was a retrospective study from the National Cancer Institute Surveillance, Epidemiology, and End Results of patients who underwent curative resection over a 15-year period (2004-2019) for primary appendiceal adenocarcinoma. Out of 16,699 patients, 14,945 were excluded (exclusion criteria were non-adenocarcinoma histological types and patients with regional or distant metastasis as per National Cancer Institute Surveillance, Epidemiology, and End Results stage). Effects of factors (age, race, tumor biology [mucinous versus non-mucinous tumors], the extent of resection of the primary lesion, and lymph nodes) on cancer-specific long-term survival were studied. Survival analysis was performed using the Kaplan-Meier method. Survival outcomes were reported as mean survival (months).

RESULTS

Of 1,754 patients, 827 (47.1%) were women, and 927 (52.1%) were men. The mean age in years (± standard deviation) was 62.43 ± 14.3. The racial distribution was as follows: Black 237 (13.5%), White 1,398 (79.7%), and Other 119 (6.8%). A total of 771 (44.6%) underwent local resection (appendectomy or segmental resection of colon without lymph node resection), and 983 (55.4%) underwent hemicolectomy with lymph node resection. Favorable survival prognosticators were age <50 years, White race, and well-differentiated histology. Patients with mucinous tumors experienced better survival. Patients who underwent right hemicolectomy with lymph node resection experienced better survival compared with those who had an appendectomy or segmental colonic resection for non-mucinous tumors rather than mucinous tumors.

CONCLUSION

We report novel demographic, tumor-related, and operative prognostic factors impacting long-term cancer-specific survival in patients who undergo resection for appendiceal adenocarcinoma. The extent of resection of the primary lesion with draining lymph nodes determines long-term cancer-specific survival in non-mucinous appendiceal adenocarcinomas.

Low grade appendiceal mucinous neoplasm metastatic to the ovary: A case report and intraoperative assessment guide

INTRODUCTION

Incidence of low grade appendiceal mucinous neoplasm is increasing. Preoperatively, it may present similarly to primary ovarian malignancy. This case report describes a case of presumed ovarian malignancy with final pathologic diagnosis of low grade appendiceal mucinous neoplasm. We also propose several surgical strategies to approach this conundrum.

PRESENTATION OF CASE

A postmenopausal woman with abdominal pain was found to have a 30 cm abdominopelvic mass with elevated CA-125 and CEA presumably a primary ovarian malignancy. During surgical staging, intraoperative findings were notable for an appendiceal mass. Intraoperative surgical oncology consultation recommended appendectomy for diagnostic purposes. Following primary surgery and final pathologic diagnosis, she underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

DISCUSSION

Low grade appendiceal mucinous neoplasm should be within the differential diagnosis of gynecologic surgeons when presented with a patient with large volume ascites and biopsy of acellular mucin. Intraoperatively, an abnormal appearing appendix with normal appearing gynecologic structures should trigger suspicion for appendiceal rather than ovarian origin. Preoperative symptoms, imaging studies, tumor markers, and frozen section pathology may not be able to differentiate between appendiceal and epithelial ovarian malignancies.

CONCLUSION

A recognition of mucinous material and abnormal appearing appendix should prompt the surgeon to consider performing an appendectomy to obtain primary pathologic diagnosis. A high level of suspicion could better optimize the patient for a joint case with the appropriate surgeons. Given the documented disguise of low grade appendiceal mucinous neoplasm as primary ovarian cancer and its increasing incidence, diagnosis and general understanding of treatment should be understood.

Appendectomy in endometriosis: an update on surgical indications and management of uncommon diseases

PURPOSE OF REVIEW

Abnormal appendiceal disease is commonly encountered following an appendectomy when performed in patients with endometriosis. Appendiceal endometriosis is the most notable finding and can affect up to 39% of patients with endometriosis. Despite this knowledge, guidelines for performing an appendectomy have not been formally established. In this article, we review the surgical indications for an appendectomy at the time of endometriosis surgery and discuss the management of other diseases that may be encountered following the histopathologic evaluation of an excised appendix.

RECENT FINDINGS

Removal of the appendix in patients with endometriosis contributes to optimal surgical management. Relying on abnormal appendiceal appearance for removal may leave endometriosis-affected appendices. For this reason, utilizing risk factors to guide surgical management is essential. Common appendiceal diseases are sufficiently managed with appendectomy. Uncommon diseases may require further surveillance.

SUMMARY

Emerging data in our field support the performance of an appendectomy at the time of endometriosis surgery. Guidelines for performing a concurrent appendectomy should be formalized to encourage preoperative counselling and management for patients with risk factors for appendiceal endometriosis. Abnormal diseases is frequently encountered after appendectomy in the setting of endometriosis surgery and further management is based on the histopathology of the specimen.

The Vermiform Appendix and Its Pathologies

The vermiform appendix is a muscular cylindrical structure originating near the junction of the cecum and ileum, averaging 9 cm (5-35 cm) in size. As the most mobile viscera, it can adopt several positions, the most common being the retrocecal position. Perceived as an atavistic organ lacking physiological relevance, the vermiform appendix appears to be involved in immune function, serving in the maturation of B lymphocytes and the production of immunoglobulin A, in endocrine function, excreting amines and hormones in the 2-3 mL of mucus secreted daily, and in digestive function, by storing beneficial bacteria from where they can recolonize the colon. With a lumen of about 6 mm, the vermiform appendix has a reduced storage capacity, so any blockage of the appendix with fecoliths (fecaliths), seeds derailed from the colon, or enlarged lymph nodes prevents drainage and intraluminal accumulation of secreted mucus. Unable to relax, the appendix wall severely limits its intraluminal volume, so mucus accumulation leads to inflammation of the appendix, known generically as appendicitis. In addition, the vermiform appendix may be the site of the development of neoplastic processes, which may or may not involve mucus production, some of which can significantly affect the standard of living and ultimately lead to death. In general, mucinous tumors may have a better prognosis than non-mucinous tumors. This review takes a comprehensive path, starting by describing the anatomy and embryology of the vermiform appendix and further detailing its inflammatory pathologies, pathologies related to congenital anomalies, and appendix tumors, thus creating an up-to-date framework for better understanding, diagnosis, and treatment of these health problems.

Appendiceal neoplasms: Suspected findings and reports of 14 cases

Background

Neoplastic lesions of the vermiform appendix are still considered to be rare, some studies suggest that appendix cancer may be on the rise, with an estimated incidence of 0.08-0.1% of all appendiceal specimens. The lifetime incidence of malignant appendiceal tumors ranges from 0.2 to 0.5%.

Patients and Methods

Our study is applied at the Department of General Surgery at tertiary training and research hospital; 14 patients who had appendectomy or right hemicolectomy between December 2015 and April 2020 were evaluated.

Results

The mean age of the patients was 52.3 ± 15.1 (range, 26-79) years. Gender of the patients were: five (35.7%) men and nine (64.3%) women. The clinical diagnosis was appendicitis without suspected findings in 11 (78.6%), appendicitis with suspected findings (appendiceal mass, etc.) in three (21.4%) of the patients, and there is no patient with asymptomatic or other rare findings. Surgeries applied for the patients were: nine (64.3%) underwent open appendectomy, four (28.6%) underwent laparoscopic appendectomy, and one (7.1%) underwent open right hemicolectomy. Histopathologic results were as follows: five (35.7%) neuroendocrine neoplasm, eight (57.1%), noninvasive mucinous neoplasm, and one (7.1%) adenocarcinoma.

Conclusion

While diagnosis and management of appendiceal pathology, surgeons should be familiar with suspected findings of appendiceal tumors and discuss them with patients to the possibility of histopathologic results.

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.

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.

A case report of appendiceal adenocarcinoma extending from the retroperitoneum to the psoas muscle

INTRODUCTION

Invasive appendiceal adenocarcinoma is rare. We describe the first reported case of appendiceal adenocarcinoma invading the psoas muscle in a 27-year-old man.

CASE PRESENTATION

The patient presented with lower right quadrant pain, persisting since the last two months. Computed tomography revealed a retroperitoneal mass with a central calcified focus in the right iliac fossa, with a mass effect on the adjacent iliopsoas muscle and apparent invasion of the cecal wall.

CLINICAL DISCUSSION

Magnetic resonance imaging showed a retrocecal appendicular mass with central necrosis. Colonoscopy showed an extra luminal mass effect that caused bulging of the ileocecal valve. Biopsy revealed lymphoid hyperplasia of the mucosa of the terminal ileum, with no malignant changes. An elective right hemicolectomy was done along with ileotransverse anastomosis. Histopathology examination of the surgical specimen revealed a moderately differentiated adenocarcinoma (Stage IV). Hence, adjuvant chemotherapy followed by hyperthermic intraperitoneal chemotherapy was employed.

CONCLUSION

Non-specific symptoms and difficulties in reaching a diagnosis pre-operatively, may contribute to underreporting of appendiceal adenocarcinomas. Besides, few therapeutic options are available due to the rarity of this tumor. Complete surgical excision and/or chemotherapy may be lifesaving.

Staging of appendiceal mucinous neoplasms: challenges and recent updates

Low-grade appendiceal mucinous neoplasms are unique tumors of the appendix, characterized by low-grade mucinous epithelium with villiform, undulating, or flat architecture. These tumors lack infiltrative growth or destructive invasion, but can extend into the appendiceal wall by a "pushing" pattern of invasion, with a broad front that can mimic a diverticulum. These neoplasms have a propensity for peritoneal dissemination, resulting in the clinical presentation of pseudomyxoma peritonei. The pathologic staging of these neoplasms is challenging and fraught with confusing terminology and numerous classification systems. This review focuses on the AJCC pathologic staging of these tumors with a focus on challenging situations.

Appendectomy Is Oncologically Equivalent to Right Hemicolectomy for Well-Differentiated T1 Appendiceal Adenocarcinoma

BACKGROUND

Right hemicolectomy is recommended for appendiceal adenocarcinoma but may not be needed for early stage disease.

OBJECTIVE

This study aimed to determine whether appendectomy offers adequate oncologic outcomes for T1 appendiceal adenocarcinoma from a national cohort of patients.

DESIGN

Patients with T1 appendiceal adenocarcinoma (mucinous and nonmucinous histology) treated with either a right hemicolectomy or appendectomy between 2004 and 2016 were retrieved. Multivariate Cox regression analysis was used to identify predictors of overall survival.

SETTING

The study was conducted using a national cancer database.

PATIENTS

A total of 320 patients (median age, 62 y; 47% women) were identified: 69 (22%) underwent an appendectomy and 251 (78%) underwent a right hemicolectomy.

MAIN OUTCOME MEASURE

Overall survival was measured.

RESULTS

Nonmucinous adenocarcinoma was identified in 194 (61%), whereas 126 (39%) had mucinous adenocarcinoma. Of the overall cohort, 43% had well-differentiated histology, 39% had moderately differentiated disease, and 4% had poorly differentiated tumors. The rate of lymph node metastasis was lower in well-differentiated tumors (3%) compared with moderately (10%) or poorly differentiated tumors (25%). On univariate survival analysis, right hemicolectomy was associated with improved 1-, 3-, and 5-year overall survival in patients with moderately/poorly differentiated disease ( p < 0.001) but not for well-differentiated disease ( p = 1.000). After adjustment, right hemicolectomy was associated with overall survival improvement for moderately/poorly differentiated T1 adenocarcinoma (HR = 0.26 [95% CI, 0.08-0.82]; p = 0.02) but not for well-differentiated disease.

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSIONS

The current analysis from the National Cancer Database demonstrates that appendectomy is associated with equivalent survival to right hemicolectomy for well-differentiated T1 adenocarcinoma, whereas for moderately and poorly differentiated disease, right hemicolectomy is oncologically superior to appendectomy. See Video Abstract at http://links.lww.com/DCR/B689 .

LA APENDICECTOMA ES ONCOLGICAMENTE EQUIVALENTE A LA HEMICOLECTOMA DERECHA PARA EL ADENOCARCINOMA APENDICULAR T BIEN DIFERENCIADO

ANTECEDENTES:La hemicolectomía derecha se recomienda para el adenocarcinoma apendicular, pero puede no ser necesaria para la enfermedad en estadio temprano.OBJETIVO:Este estudio tuvo como objetivo determinar si la apendicectomía ofrece resultados oncológicos adecuados para el adenocarcinoma apendicular T1 de una cohorte nacional de pacientes.DISEÑO:Se recuperaron pacientes con adenocarcinoma apendicular T1 (histología mucinoso y no mucinoso) tratados con hemicolectomía derecha o apendicectomía entre 2004-2016. Se utilizó un análisis de regresión de Cox multivariante para identificar los predictores de la supervivencia global.ENTORNO CLÍNICO:Base de datos nacional sobre cáncer.PACIENTES:Se identificaron un total de 320 pacientes (mediana de edad 62 años, 47% mujeres): 69 (22%) se sometieron a una apendicectomía y 251 (78%) se sometieron a una hemicolectomía derecha.PRINCIPAL MEDIDA DE RESULTADO:Sobrevida global.RESULTADOS:Se identificó adenocarcinoma no mucinoso en 194 (61%) mientras que 126 (39%) tenían adenocarcinoma mucinoso. De la cohorte general, el 43% tenía una histología bien diferenciada, el 39% tenía una enfermedad moderadamente diferenciada y el 4% tenía tumores poco diferenciados. La tasa de metástasis en los ganglios linfáticos fue menor en los tumores bien diferenciados (3%) en comparación con los tumores moderadamente (10%) o pobremente diferenciados (25%). En el análisis de sobrevida univariante, la hemicolectomía derecha se asoció con una mejor sobrevida general a 1, 3, y 5 años en pacientes con enfermedad moderada / pobremente diferenciada ( p < 0,001) pero no para la enfermedad bien diferenciada ( p = 1,000). Después del ajuste, la hemicolectomía derecha se asoció con una mejora de la sobrevida general para el adenocarcinoma T1 moderadamente / poco diferenciado (HR = 0,26, IC del 95%: 0,08-0,82, p = 0,02) pero no para la enfermedad bien diferenciada.LIMITACIONES:Este estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES:El análisis actual de la base de datos nacional de cáncer demuestra que la apendicectomía se asocia con una sobrevida similar a la hemicolectomía derecha para el adenocarcinoma T1 bien diferenciado, mientras que para la enfermedad moderada y pobremente diferenciada, la hemicolectomía derecha es oncológicamente superior a la apendicectomía. Consulte Video Resumen en http://links.lww.com/DCR/B689 . (Traducción-Dr. Yazmin Berrones-Medina ).

Management of Appendix Neuroendocrine Neoplasms: Insights on the Current Guidelines

Appendiceal neuroendocrine neoplasms (ANENs) usually present as incidental findings at the time of appendectomy for acute appendicitis. They are rare, accounting for only 0.5-1% of intestinal neoplasms; they are found in 0.3-0.9% of all appendectomy specimens. They are usually sporadic tumors. There are several histological types including well-differentiated neuroendocrine tumors (NETs), poorly differentiated neuroendocrine carcinomas (NECs), and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). Histologic differentiation and the grade of well-differentiated NETs correlate with clinical behavior and prognosis. Management varies based on differentiation, aggressiveness, and metastatic potential. There is debate about the optimal surgical management for localized appendiceal NETs that are impacted by many factors including the tumor size, the extent of mesoappendiceal spread, lymphovascular invasion and perineural involvement. In addition, the data to guide therapy in metastatic disease are limited due to the paucity of these tumors. Here, we review the current advances in the management of ANENs within the context of a multidisciplinary approach to these tumors.

Do Lymph Node Metastases Matter in Appendiceal Cancer with Peritoneal Carcinomatosis? A US HIPEC Collaborative Study

BACKGROUND

Whether formal regional lymph node (LN) evaluation is necessary for patients with appendiceal adenocarcinoma (AA) who have peritoneal metastases is unclear. The aim of this study was to evaluate the prognostic value of LN metastases on survival in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

METHODS

A retrospective analysis of the US HIPEC collaborative, a multi-institutional consortium comprising 12 high-volume centers, was performed to identify patients with AA who underwent CRS-HIPEC with adequate LN sampling (≥ 12 LNs).

RESULTS

Two hundred-fifty patients with AA who underwent CRS-HIPEC were included. Outcomes were compared between LN - and LN + disease. Baseline patient characteristics between groups were similar, with most patients undergoing complete cytoreduction (0/1: 86.0% vs. 76.8%, p = 0.08), respectively. More adverse tumor factors were found in patients with LN + disease, including poor differentiation, signet ring cells, and lymphovascular invasion. Multivariate analysis of overall survival (OS) found LN + disease was independently associated with worse OS (HR: 2.82 95%CI: 1.25-6.34, p = 0.01), even after correction for receipt of systemic therapy. On Kaplan-Meier analysis, median OS was lower in patients with LN + disease (25.9 months vs. 91.4 months, p < 0.01). LN + disease remained associated with poor OS following propensity score matching (HR: 4.98 95%CI: 1.72-14.40, p < 0.01) and in patients with PCI ≥ 20 (HR: 3.68 95%CI: 1.54-8.80, p < 0.01).

CONCLUSIONS

In this large multi-institutional study of patients with AA undergoing CRS-HIPEC, LN status remained associated with worse OS even in the setting of advanced peritoneal carcinomatosis. Formal LN evaluation should be performed for most patients with AA undergoing CRS-HIPEC.