Challenges and predictive radiological findings in the diagnosis of neuroendocrine tumors in patients with acute appendicitis.

BACKGROUND: Acute appendicitis is one of the most common surgical emergencies. With antibiotic-first treatment strategies gaining importance, the risk of an appendiceal tumor as an incidental finding or as the cause of appendicitis presents an obstacle to a conservative approach. Neuroendocrine tumors, the most frequent type of appendiceal tumors, are difficult to diagnose preopera-tively due to their small size. This study aims to identify predictive factors for neuroendocrine tumors in patients undergoing surgery for acute appendicitis by analyzing imaging and clinical characteristics, thereby enhancing preoperative diagnostic accuracy and guiding surgical interventions. METHODS: This retrospective observational study included 1,298 patients who underwent appendectomy from January 2014 to May 2024. After excluding 59 patients with normal pathology results, 40 with variable pathologies, and 49 with inaccessible computed tomography (CT) images, 1,150 patients remained (1,135 with acute appendicitis and 15 with neuroendocrine tumors). Abdominal CT scans were evaluated for appendiceal diameter, wall thickness, cecal wall thickness, periappendiceal fat stranding, fluid collection, lymphadenopathy, intraluminal and free periappendiceal air, mucosal hyperenhancement, the presence of appendicolith, mural calcification, and mural nodules. RESULTS: The presence of a mural nodule protruding into the lumen was significantly higher in neuroendocrine tumor patients compared to those with acute appendicitis, with a sensitivity of 53.3%, specificity of 95.8%, positive predictive value (PPV) of 31.9%, negative predictive value (NPV) of 99.4%, and accuracy of 97.9%. Intraluminal air was also more frequent in neuroendocrine tumor patients, with a sensitivity of 53.3%, specificity of 76.7%, PPV of 2.9%, NPV of 99.2%, and accuracy of 76.4%. Other imaging parameters did not show significant differences between the two groups. CONCLUSION: This study identifies mural nodules and intraluminal air as significant predictors of neuroendocrine tumors in patients with acute appendicitis, emphasizing the importance of meticulous preoperative imaging evaluations. Incorporating these predictors into diagnostic protocols could improve the preoperative identification of neuroendocrine tumors, enabling more appropriate surgical interventions. Future research should validate these findings through prospective studies and explore advanced imaging techniques to further enhance the detection of appendiceal neoplasms, ultimately improving patient outcomes and reducing overlooked malignancies.

[A Case of Low-Grade Appendiceal Mucinous Neoplasm-A Complex Preoperative Diagnosis].

A 63-year-old woman was admitted to our hospital with suspected appendicitis. Abdominal CT revealed an enlarged appendix, and findings consistent with some small nodules. She was diagnosed with appendicitis and successfully treated with antibiotics. Contrast-enhanced CT performed 2 months after discharge revealed a reduction in small nodules, and tumor markers were not elevated. Therefore, we concluded that this case was unlikely to be an appendiceal tumor. Interval appendectomy was performed laparoscopically, and histopathological analysis revealed a low-grade appendiceal mucinous neoplasm(LAMN). Herein, we present this case and review the relevant literature.

Molecular Profiling of Low-Grade Appendiceal Mucinous Neoplasms (LAMN).

Low-grade appendiceal mucinous neoplasia (LAMN) represents a relatively rare tumor of the appendix typically diagnosed incidentally through appendectomy for acute appendicitis. In cases where perforation occurs, mucinous content may disseminate into the abdominal cavity, leading to the development of pseudomyxoma peritonei (PMP). The primary objective of this study was to elucidate the molecular characteristics associated with various stages of LAMN and PMP. DNA was extracted from LAMN, primary PMPs, recurrent PMPs, and adenocarcinomas originating from LAMN. The subsequent analysis involved the examination of mutational hotspot regions within 50 cancer-related genes, covering over 2800 COSMIC mutations, utilizing amplicon-based next-generation sequencing (NGS). Our findings revealed activating somatic mutations within the MAPK-signaling pathway across all tumors examined. Specifically, 98.1% of cases showed mutations in KRAS, while one tumor harbored a BRAF mutation. Additionally, GNAS mutations were identified in 55.8% of tumors, with no significant difference observed between LAMN and PMP. While LAMN rarely displayed additional mutations, 42% of primary PMPs and 60% of recurrent PMPs showed additional mutations. Notably, both adenocarcinomas originating from LAMN showed mutations within TP53. Furthermore, 7.7% (4/52) of cases exhibited a potentially targetable KRAS G12C mutation. In four patients, NGS analysis was performed on both primary PMP and recurrent PMP/adenocarcinoma samples. While mutations in KRAS and GNAS were detected in almost all samples, 50% of recurrent cases displayed an additional SMAD4 mutation, suggesting a notable alteration during disease progression. Our findings indicate two key points: First, mutations within the MAPK pathway, particularly in KRAS, are evident across all tumors, along with a high frequency of GNAS mutations. Second, progression toward PMP or adenocarcinoma is associated with an accumulation of additional mutations within common oncogenic pathways.

Appendiceal adenocarcinoma associated with Amyand's hernia: a case report.

We encountered a rare case of appendiceal carcinoma associated with Amyand's hernia, which was difficult to diagnose preoperatively. A 74-year-old man presented to our hospital with right lower abdominal pain. A hard mass was palpable in the right lower abdomen, and blood tests showed a slightly elevated inflammatory response. Computed tomography revealed a 7 × 5 cm mass with indistinct borders and heterogeneous internal density extending from the cecum to the right lower abdominal wall. We diagnosed appendiceal abscess, however, percutaneous biopsy which was performed for differential diagnosis with appendiceal carcinoma showed no malignancy. Thereafter, the patient was followed up. Two months later, a blood test showed insignificant changes in the inflammatory response and a high serum carcinoembryonic antigen level (48.6 ng/mL). An ultrasound showed a mass contiguous to the appendix, extending to the abdominal wall, with abundant blood flow signals. Fluorodeoxyglucose-positron emission tomography showed a high accumulation of fluorodeoxyglucose in the mass. Four months after the initial visit, the patient had an open ileocecal resection combined with an abdominal wall resection based on the preoperative diagnosis of appendiceal carcinoma invading the abdominal wall. During laparotomy, an enlarged appendix tip extended from the internal inguinal ring outside the inferior epigastric artery to the abdominal wall. Histopathological examination of the appendiceal tumor revealed well-differentiated adenocarcinoma, T4b (abdominal wall), N0, Ly0, and V0. When a right lower abdominal mass extends from the cecum to the abdominal wall, appendiceal tumors associated with Amyand's hernia should be considered.

Mutational Features and Tumor Microenvironment Alterations in High-Grade Appendiceal Cancers Treated With Iterative Hyperthermic Intraperitoneal Chemotherapy.

PURPOSE: High-grade appendiceal adenocarcinomas (HGAA) with peritoneal metastases (PMs) are associated with poor survival. Hyperthermic intraperitoneal chemotherapy (HIPEC) is a novel treatment approach for unresectable HGAA-PM. However, its influence on immunogenomic profiles has not yet been fully explored. MATERIALS AND METHODS: We obtained 79 samples of metastatic peritoneal tumor deposits from patients diagnosed with HGAA and performed whole-exome sequencing, RNA sequencing, and immunoprofiling before and after HIPEC. Tumor biopsies were subjected to immunogenomic profiling to detect mutational signatures and immune populations associated with oncologic outcomes. RESULTS: Fifteen patients with HGAA-PMs were included in the study. The median progression-free survival (PFS) was 6.7 months (2.7-25.3) and the median overall survival was 11.4 months (4.7-42). Mucin-associated genes (MUC16, MUC3A, and MUC5AC) and titin (TTN) had the highest mutation frequencies. Mutational signatures such as single-base substitution 29 and doublet-base substitution 11 were present in >50% of single-base and double-base mutations. Higher PD-L1 coexpression on CD8+ T cells demonstrated a higher PFS both intratumorally (P = .019) and at the margin (P = .025). CONCLUSION: HIPEC-associated mutational signatures were identified in HGAA-PMs. Elevated PD-L1+ cytotoxic T-cell populations after HIPEC had better PFS, offering valuable insights for prognostication in the context of HIPEC treatment.

[Clinical characteristics of appendix orifice polyps and the effect endoscopic super minimally invasive treatment].

To analyze the clinical characteristics of appendiceal orifice polyps and the effect of endoscopic super minimally invasive treatment. A retrospective analysis was conducted on the general situation (age and sex), the classification of appendiceal orifice polyps, the treatment method under endoscope, postoperative pathology and postoperative complications in patients who underwent resection of appendiceal orifice polyps at the Peking University First Hospital and the First Medical Center of the PLA General Hospital from January 1, 2022, to December 31, 2023. A total of 47 patients were included, consisting of 28 males and 19 females, with 35-86 (61±12) years. Appendiceal orifice polyps were classified into four types: type 0 (14 cases), type 1 (15 cases), type 2 (12 cases), and type 3 (6 cases). Among the endoscopic morphologies, 22 cases were granular laterally spreading tumors. Endoscopic mucosal dissection was performed in 37 cases. Postoperative appendiceal stent placement was performed in 1 case. The pathological types of polyps included adenoma in 15 cases, high-grade intraepithelial neoplasia in 10 cases, intramucosal carcinoma in 4 cases, submucosal carcinoma in 5 cases, inflammatory polyps in 1 cases, and sessile serrated lesion in 12 cases. Curative resection was performed in 44 cases. There were no postoperative complications such as bleeding, perforation, or acute appendicitis. The pathology of appendiceal polyps is mostly precancerous lesions, and the treatment scheme of endoscopic super minimally invasive resection is both safe and effective.

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.

Impact of PIPAC-Oxaliplatin on Functional Recovery, Good Days, and Survival in a Refractory Colorectal and Appendiceal Carcinomatosis: Secondary Analysis of the US PIPAC Collaborative Phase 1 Trial.

BACKGROUND: Pressurized intraperitoneal aerosolized chemotherapy (PIPAC) is a novel, minimally invasive, safe, and repeatable method to treat carcinomatosis. Evidence regarding the clinical benefit (quality of life and survival) of PIPAC compared with that of conventional standard therapy (ST) is lacking. METHODS: This is the secondary analysis of the phase 1 US-PIPAC trial for refractory colorectal and appendiceal carcinomatosis. A PIPAC cohort was compared with a retrospective cohort of consecutive patients receiving ST. The primary outcome was number of good days (number of days alive and out of the hospital). The secondary outcomes were overall survival (OS), progression-free survival (PFS), health-related quality of life (HRQoL), and objective functional recovery (daily step count). RESULTS: The study included 32 patients (PIPAC, 12; ST, 20) with similar baseline characteristics. Compared with the ST cohort, the PIPAC cohort had lower median inpatient hospital stays (> 24 h) within 6 months (0 vs 1; p = 0.015) and 1 year (1 vs 2; p = 0.052) and higher median good days at 6 months (181 vs 131 days; p = 0.042) and 1 year (323 vs 131 days; p = 0.032). There was no worsening of HRQoL after repeated PIPACs. Step counts diminished immediately after PIPAC but returned to baseline within 2-4 weeks. Kaplan-Meier analysis demonstrated a favorable association between receipt of PIPAC and OS (median, 11.3 vs 5.1 months; p = 0.036). CONCLUSION: Compared with ST, PIPAC was associated with higher number of good days, reduced hospitalization burden, and longer OS without a negative impact on HRQoL with repeated PIPACs. These findings are foundational for evaluation of PIPAC in a randomized clinical trial.

Goblet cell adenocarcinoma.

Appendix, considered a vestigial and disposable organ, has been long neglected as a source of abdominal tumors. Among the appendiceal tumors, goblet cell adenocarcinoma (GCA) is a rare primary epithelial neoplasm which has undergone multiple name changes and classifications in recent years, adding to confusion surrounding this unique amphicrine tumor. This entity was previously known as goblet cell carcinoid and adenocarcinoma ex goblet cell carcinoid. This review article provides an update on pathology, nomenclature, and recent classification systems with emphasis on 2019 World Health Organization Classification of Tumors, 3-tiered grading system.1.

Exploring the mysterious mucinous appendiceal neoplasm.

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

Appendiceal adenocarcinoma: Current concepts & challenges.

Appendiceal adenocarcinoma (ApAC) is a rare malignancy, comprising less than 1 % of all gastrointestinal tumors. The current World Health Organization classifies ApAC as mucinous or nonmucinous. Mucinous ApAC are composed of pools of mucin lined by cells with low- and high-grade cytology and areas of infiltrative invasion. Nonmucinous ApAC histologically resemble conventional colorectal adenocarcinomas and have a worse prognosis than their mucinous counterpart. Unfortunately, the nomenclature and histologic classification of ApAC, specifically the mucinous subtype, has changed several times throughout the years, contributing to diagnostic confusion for pathologists. The treatment for mucinous ApAC differs from that of other appendiceal mucinous neoplasms, thus accurate diagnosis is key to patient management and outcome. This review discusses the current classification and staging of ApAC with a particular emphasis on the mucinous subtype and peritoneal disease, as these areas are the most challenging for practicing surgical pathologists.

Association between preoperative appendiceal histology grade and Pseudomyxoma peritonei grade offers a solution to avoid right hemicolectomy during cytoreductive surgery and HIPEC.

INTRODUCTION & OBJECTIVES: Treatment of PMP consists of appendectomy, cytoreductive surgery (CRS) and HIPEC. Right-sided hemicolectomy is necessary only when PMP is high grade, given the lymphatic invasion risk. To date, no single preoperative factor was identified as predictive of PMP grade. MATERIALS & METHODS: Preoperative factors of a prospective cohort study on PMP were retrospectively analyzed, in order to identify situations linked with high or low grade appendiceal PMP. The main outcome was PMP grade on definitive histology after CRS. RESULTS: n = 105. In univariate analysis, the grade of the appendiceal tumor, systematically reviewed in an expert center, showed an OR of 25.00 (95 % CI: 3.30-189.27; p = 0.001) and an NPV of 93.75 [85.36, 100]. Peritoneal biopsy demonstrated an OR of 19.80 (95 % CI: 2.30-170.71; p = 0.002) and a PPV of 90 [71.41, 100]. In multivariate analysis, these two factors remained significantly associated with PMP grade. CONCLUSION: Whenever appendiceal tumor is low grade on preoperative histology, the colon has to be spared unless completeness of CRS is compromised, which is a high-grade feature in fact. In case of high grade appendiceal tumor and/or peritoneal biopsy, right-sided hemicolectomy is warranted. If no histology is available preoperatively, adapt to intraoperative lesions as no preoperative factors seem to be predictive.

The risk of developing pseudomyxoma peritonei from a non-perforated low grade appendiceal mucinous neoplasm found at appendicectomy.

INTRODUCTION: Low-grade appendiceal mucinous neoplasms (LAMNs) are classified as non-perforated (pTis, pT3) or perforated (pT4), and considered precursors of pseudomyxoma peritonei (PMP). This study aims to quantify the risk of developing PMP from pTis and pT3 LAMNs. MATERIALS AND METHODS: Retrospective analysis of a prospectively collected database identified LAMN patients referred to a specialist centre from 2004 to 2019. pT4 LAMNs and other appendix tumours were excluded. All patients had specialist review of their pathology, operation note, and a CT scan (at least 6 weeks post-operatively). Surveillance CTs were then performed at 6, 12, 24, 36, 48, & 60 months, with tumour markers (CEA, CA19-9, CA125). RESULTS: 193 pT3/pTis LAMN patients were included (pTis = 153, pT3 = 40). Median follow-up = 6.45 (3.91-22.13) years, M:F ratio = 1:1.57, and median age = 57 (23-83) years. Initial surgery included: appendicectomy (67 %), appendicectomy + visceral resection (6 %), and right hemicolectomy (27 %). R1 resections were identified in 5/193 patients (2.5 %). 3 R1 patients underwent re-operation (2 caecal pole excision and 1 ileocecectomy), none of which had residual tumour. 8/193 patients (4 %) were lost to follow up. None of the remaining 185 developed PMP. CONCLUSION: This is the largest reported series of pTis/pT3 LAMNs with standardised follow-up in the literature. LAMNs correctly classified as pT3/pTis (after careful specialist review of pathology, operation note, and a baseline post-operative CT) have negligible risk of developing PMP and should have low intensity surveillance. If completely excised, further surgery is not indicated. R1 resections should be considered on an individual basis at a specialist centre.

Decision Regret in Patients with Appendiceal Cancer Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Decision regret is an emerging patient reported outcome. The aim of this study was to assess the incidence of regret in patients with appendiceal cancer (AC) who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). PATIENTS AND METHODS: An anonymous survey was distributed to patients through the Appendix Cancer and Pseudomyxoma Peritonei (ACPMP) Research Foundation. The Decision Regret Scale (DRS) was employed, with DRS > 25 signifying regret. Patient demographics, tumor characteristics, postoperative outcomes, symptoms (FACT-C), and PROMIS-29 quality of life (QoL) scores were compared between patients who regretted or did not regret (NO-REG) the procedure. RESULTS: A total of 122 patients were analyzed. The vast majority had no regret about undergoing CRS-HIPEC (85.2%); 18 patients expressed regret (14.8%). Patients with higher regret had: income ≤ $74,062 (72.2% vs 44.2% NO-REG; p = 0.028), major complications within 30 days of surgery (55.6% vs 15.4% NO-REG; p < 0.001), > 30 days hospital stay (38.9% vs 4.8% NO-REG; p < 0.001), a new ostomy (27.8% vs 7.7% NO-REG; p = 0.03), >1 CRS-HIPEC procedure (56.3% vs 12.6% NO-REG; p < 0.001). Patients with worse FACT-C scores had more regret (p < 0.001). PROMIS-29 QOL scores were universally worse in patients with regret. Multivariable analysis demonstrated > 30 days in the hospital, new ostomy and worse gastrointestinal symptom scores were significantly associated with regret. CONCLUSIONS: The majority of patients with AC undergoing CRS-HIPEC do not regret undergoing the procedure. Lower income, postoperative complications, an ostomy, undergoing > 1 procedure, and with worse long-term gastrointestinal symptoms were associated with increased regret. Targeted perioperative psychological support and symptom management may assist to ameliorate regret.

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.

Analytical interference in CA 19-9 immunoassay generates false-positive results in a young woman with a low-grade appendiceal tumor: An educational case report and brief literature review.

CA 19-9 (carbohydrate antigen 19-9) is a tumor marker widely used for the follow-up of patients with pancreatic cancer and other digestive neoplasia. This case report describes a discrepancy between the results of serum CA 19-9 analyses using the Alinity analytical platform (Abbott™) and two other techniques, Kryptor Gold (ThermoFisher Scientific™) and Cobas E411 (Roche™), in the context of a young woman with appendiceal mucocele. In this context, when the serum concentration of CA 19-9 is high, it may raise concerns about potential malignancy or rupture of the mucocele that may lead to tumoral dissemination in the abdominal cavity. In the present case, we observed with Alinity a false elevation in CA 19-9 concentration at 190 kU/L (normal range < 37 kU/L) before appendix resection that continued to increase until reaching 619 kU/L six months after surgery. This situation led to unnecessary additional tests, increased hospitalization time and stress for the patient who also had to interrupt her medically assisted reproduction project. We solved this case using new measurements in CA 19-9 concentration with two other techniques, Kryptor Gold and Cobas E411, and we identified an analytical interference caused by the presence of heterophile antibodies. In all cases, abnormal result initially obtained with Alinity was found below normal range not only with the two other techniques but also with Alinity after a neutralisation step by using Heterophile Blocking Tubes (Scantibodies Laboratory™). Analytical interferences in medical tests can lead to inappropriate medical care. It is an important issue requiring a continuing training of biologists who must be aware of these problems, which are recurring concerns and are not always easy to identify in laboratories of medical biology, in particular when immunoassays are used. This case report also provides an opportunity to do a brief review of the literature and to remind some recommendations and actions to take into consideration in the presence of discrepancies between the clinic and the biology, in particular, one of them is to measure the biological analyte with a different technique. Moreover, the use of Heterophile Blocking Tubes neutralizing specifically the heterophile antibodies may be useful. In all cases, dialogue between clinicians and biologists remains essential.

Appendiceal neoplasms in Saudi Arabia: prevalence and clinicopathological profile.

BACKGROUND: The appendix is a small organ with no particular known function. Primary appendiceal neoplasms (ANs) are rare. While the prevalence is increasing worldwide over the past two decades, no apparent increase in the prevalence of ANs has been reported in the Arabian Gulf States. Recently, a significant decline in the age at diagnosis of some types of ANs has been reported worldwide, with a female predominance. OBJECTIVES: Evaluate the prevalence and clinicopathological characteristics of ANs within our institution in Saudi Arabia and compare them to limited existing studies from different regions as well as the Arabian Gulf States. DESIGN: Retrospective cohort. SETTING: Tertiary care center in Riyadh. PATIENTS AND METHODS: All patients who underwent appendectomy and had the appendix submitted for histopathological evaluation between May 2015 and June 2020 were included to allow for a follow-up of 5 years or more at the time of data collection. MAIN OUTCOME MEASURES: Demographics, clinical presentations, surgical interventions, histopathological findings, complications, and recurrence rates. SAMPLE SIZE: 25 AN patients. RESULTS: Of 1110 patients, 25 had ANs (13 female and 12 male participants) with a mean (standard deviation) age of 54.6 (14.1) years. Only 40% presented with acute appendicitis, 64% had comorbidities, and less than 50% underwent laparoscopic appendectomy. Histopathologically, 72% were low-grade appendiceal mucinous neoplasms (LAMNs). Complications were minimal grades (Clavien-Dindo classification), with 80% experiencing none. The mean hospital stay was 9.96 days. Local recurrence occurred in 8% of cases, and distant metastasis was documented in one adenocarcinoma case. However, the 5-year overall and disease-free survival rates were 88% and 80%, respectively. CONCLUSIONS: The incidence of ANs is increasing in Saudi Arabia with the higher prevalence of LAMNs. The pathological examination of the resected appendix played a pivotal role in the diagnosis of ANs. LIMITATIONS: Data collected retrospectively, a single institution, and a small population.

[Long-Term Survival of a Case with Peritoneal Dissemination from Appendiceal Goblet Cell Carcinoid Treated with Systemic Chemotherapy].

A 64-year-old man complained of lower abdominal pain and vomiting. The CT scan showed adhesional ileus; therefore, small bowel resection procedure was performed. Histological findings showed signet-ring cell carcinoma and poorly differentiated adenocarcinoma. We performed ileocecal resection as an additional surgery. The operative findings revealed peritoneal nodules. The histological findings suggested goblet cell carcinoid with peritoneal dissemination. mFOLFOX+bevacizumab was administered, and no progression was observed for 30 months after the surgery. Appendiceal goblet cell carcinoid is rare and its prognosis is poor. Here, we report a case of appendiceal GCC that achieved a relatively long-term survival despite peritoneal dissemination.