Appendiceal Mucinous Neoplasm Research Articles

Low-grade appendiceal mucinous neoplasm with obstruction of the terminal ileum: A case report

Low-grade appendiceal mucinous neoplasm with obstruction of the terminal ileum: A case report

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

This study aimed to reveal the incidence, clinicopathological, and oncological outcomes of appendiceal neoplasms. 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. 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. Appendiceal neoplasms are rare but remain an important cause of mortality. Appendiceal adenocarcinomas are associated with poorer oncological outcomes compared to other neoplasms.

Varied Histomorphological Presentations of Appendiceal Neoplasms: A Case Series of Eight Cases

During routine histopathological study of appendicular specimens, we identified eight cases of appendiceal tumours, including five cases of Low-grade Appendiceal Mucinous Neoplasms (LAMN) and three cases of adenocarcinoma. Among the adenocarcinoma cases, one was a rare colorectal type adenocarcinoma in an older male and two were mucinous adenocarcinoma which includes a case of signet ring cell rich type. These tumours were classified and staged according to the recent WHO classification (5th edition) and the eighth edition of the American Joint Committee of Cancer (AJCC) staging manual. The median age in our series was 60 years. Serum markers were evaluated in two cases of Pseudomyxoma Peritonei (PMP), which showed elevated levels of CA-125 and CA 19.9 in each case. In this case series, three patients were initially diagnosed with acute appendicitis, one case as mucocele, two cases underwent surgery for ovarian malignancy, one patient was operated for an incisional hernia, and one patient was diagnosed with acute intestinal obstruction after clinical and radiological investigations. Histopathological examination confirmed the diagnosis of appendicular neoplasms in these eight cases. Meticulous histopathological examination of all appendectomy specimens is important for the proper diagnosis of appendicular neoplasms and to predict their severity. This will help surgeons plan further treatment to increase the patient's survival rate.

Histopathological examination after appendectomy: Neoplastic lesions

Appendiceal neoplasms include rare tumor formations, whose treatment ranges from an appendectomy, hemicolectomy, and chemotherapeutic agents for benign or malignant lesions. In this study, we aimed to evaluate appendiceal neoplastic lesions according to the literature on histological subgroups. A review was performed on 2.124 patients who had undergone appendectomy between January 2017 and December 2021. Patients were evaluated retrospectively according to their demographic, clinical, radiological, and histopathological characteristics. In the histopathological evaluation of the 23 (1.06%) patients, who were included in the study upon the detection of the appendiceal neoplastic lesion, sessile serrated adenoma was observed in 7 patients, low-grade appendiceal mucinous neoplasm (LAMN) in 6 patients, mucinous adenocarcinoma in 4 patients, signet ring cell mucinous adenocarcinoma in 1 patient, neuroendocrine tumor (NET) in 4 patients, and tubulovillous adenoma in 1 patient. Appendiceal neoplasms are generally asymptomatic; therefore, pathological examination results should be carefully evaluated after appendectomy, and it should be remembered that appendectomy is not always sufficient alone.

Low-grade Appendiceal Mucinous Neoplasm: A Series of Four Cases

Low-grade Appendiceal Mucinous Neoplasm (LAMN) is a rare malignant neoplasm seen in less than 0.3% of appendectomy specimens. Patients with LAMN can present with abdominal pain, mimicking appendicitis clinically. In later stages, it can rupture, leading to Pseudomyxoma peritonei (PMP). Therefore, a high clinical suspicion is needed for correct diagnosis and management. The prognosis of LAMN depends on the presence or absence of mucin/neoplastic epithelium outside the appendix. For LAMN confined to the appendix, appendectomy alone is sufficient for management, with conservative follow-up. For LAMN with extruded acellular mucin localised to the appendiceal serosa, management involves appendectomy and PMP surveillance. For all mucinous lesions of the appendix, it is essential to submit the entire appendix for histopathologic examination, thoroughly evaluating the presence of mucin/neoplastic epithelium involving the serosa/extra appendiceal tissue for accurate staging and to predict the risk of recurrence and determine further management. Here four cases of LAMN due to their rarity and clinical importance is presented. This study of four cases emphasises that the clinical diagnosis of this rare malignancy is difficult, and radiological investigations were not available as these patients presented with clinical features mimicking appendicitis. Emergency appendectomy was performed in all cases. LAMN should be considered as a differential diagnosis because if not diagnosed and treated in the early stages, it can lead to dreaded complications like PMP. The histopathological examination of all four cases of LAMN showed dissecting acellular mucin in various stages of progression in the appendicular wall, but none involving the serosa. This highlights the importance of timely surgical intervention and histopathological examination for an exact diagnosis and staging of LAMN for further follow-up or treatment.

High Grade Appendiceal Mucinous Neoplasm Presenting as Intussusception In an Elderly Female-A Case Report

Introduction: Appendiceal mucinous neoplasms (AMNs) are rare and account for 1% of gastrointestinal neoplasms and the diagnosis is mostly incidental. In spite of advances in the understanding of AMNs and their association with peritoneal disease, AMNs are still confusing entities in respect to their diagnosis and treatment alike.
 Case Report: We report a case of a 51year old female who presented with abdominal pain and vomiting and was diagnosed as ileo-colic intussusception on ultrasonography and CECT abdomen. Histopathological examination of right hemicolectomy specimen revealed a high grade appendicular mucinous neoplasm with low grade areas. The peri-appendiceal mucin deposition forming a mass in the cecum at the base of appendix was the lead point for intussusception in this case. No features of pseudomyxoma peritonei was seen in this case. This patient is well after 18 months of follow up period.
 Conclusion: Appendiceal mucinous neoplasms are rare and diagnosis is often difficult as presentation is mostly non-specific. Hence, awareness and further classification of these tumours is essential for diagnosis, determining the risk of recurrence and malignancy and also prognostication.

Rare presentation of low-grade appendiceal mucinous neoplasms (LAMN) as an appendicular lump: A case report

The prevalence of appendiceal mucinous neoplasms (AMN) is about 0.2%-0.3% in the specimens of the appendix. The LAMN may appear unremarkable or can present as mucin-filled, crystally dilated tissues. The diagnosis of early-stage AMN is mostly incidental. It is of vital importance to know the features of LAMN for a timely diagnosis. A 46-year-old male came with the complaint of right iliac fossa swelling along with severe intensity pain and a single episode of vomiting. A 4×4cm tender, soft, cystic, mobile swelling was found upon the examination. Contrast-enhanced Computerized tomography (CT) scan of the abdomen revealed the appendix diameter of 10mm well-circumscribed cystic measuring 2.1×2 cm. Therefore, an open resection surgery was performed. The histopathological report revealed an intraepithelial lesion composed of flat mucinous epithelial cells having eosinophilic cytoplasm and low-grade nuclear atypia. The AMNs are very rare neoplasms. The imaging modalities that can be diagnostic methods are abdominal and transvaginal ultrasonography (US), and abdominal computed tomography (CT). The low-grade features of the appendiceal mucinous neoplasms have the possibility of recurrence. The CT-scan findings of appendiceal lump>1.3cm along with cystic dilation and the calcification of the wall are the suggestive features of AMN. There is a high chance of dissemination and port site seeding in case of pneumoperitoneum. This rare case suggests the significance of adding AMNs as a differential diagnosis in patients with abdominal pain and choosing the right approach to treat such patients to avoid complications.

Differential expression of Chitinase 3-Like 1 protein in appendicitis and appendix carcinomas.

Chitinase 3-Like 1 (CHI3L1) has been used as an inflammatory biomarker for a variety of diseases, but its expression in acute appendicitis and appendix carcinomas remains unclear. Sixty cases of patients were studied, including 46 acute appendicitis and 14 appendix carcinomas. We divided the acute appendicitis group into acute uncomplicated appendicitis (AUA), suppurative appendicitis (SA), and gangrenous appendicitis (GA). The appendix carcinoma group was divided into appendiceal neuroendocrine neoplasms (ANENs) and appendiceal mucinous neoplasms (AMN). Controls were 32 healthy donors. Blood neutrophil to lymphocyte ratio (NLR), CHI3L1, C-reactive protein (CRP), interleukin-6 (IL-6), and serum amyloid A (SAA) were measured in the patients. Meanwhile, immunohistochemistry and immunofluorescence were used to identify the expression level and location of CHI3L1 in different cell types in appendix tissues. Compared with the controls, CHI3L1 serum levels were up-regulated in SA, GA, and AMN groups, while no significant difference was observed in the AUA and ANEN groups. Immunofluorescence revealed that CHI3L1 expression was high in macrophages and adenocarcinoma cells of appendix tissues but not in the neuroendocrine carcinoma tissues. Moreover, levels of NLR and CRP in the SA and GA groups were considerably higher than in the control group. IL-6 and SAA in SA, GA, ANENs, and AMN groups were also increased compared with the control group. In addition, CHI3L1 displayed good performance in predicting appendicitis, with an AUC of 0.862. CHI3L1 was highly expressed in acute appendicitis and appendiceal mucinous neoplasms, which can be used as a novel biomarker predicting appendicitis.

Retrospective Review of Outcomes in Non-Invasive Mucinous Appendiceal Neoplasms with and without Peritoneal Spread: A Cohort Study

Patients treated surgically for local non-invasive mucinous appendiceal neoplasm (NI-MAN) may recur with the development of peritoneal dissemination (PD). The risk of recurrence and predictive factors are not well studied. Patients with NI-MAN, with or without peritoneal dissemination at presentation, were included. Patients with limited disease underwent surgical resection only. Patients with peritoneal dissemination underwent cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC). Patients without PD (nPD) were compared to those who presented with PD. Thirty-nine patients were included, 25 in nPD and 14 in PD. LAMN was diagnosed in 96% and 93% of patients in nPD and PD, respectively. Acellular mucin on the peritoneal surface was seen in 16% of nPD patients vs. 50% of PD patients (p = 0.019). Two (8%) patients in the nPD group who had LAMN without wall rupture recurred, at 57 and 68 months, with a PCI of 9 and 22. The recurrence rate in the PD group was 36%. All recurred patients underwent CRS+HIPEC. A peritoneal recurrence is possible in NI-MANs confined to the appendix even with an intact wall at initial diagnosis. The peritoneal disease may occur with significant delay, which is longer than a conventional follow-up.

Appendiceal Mucinous Tumor Presenting as Recurrent Bowel Obstruction.

Appendiceal mucinous tumors are rare, with variable malignant potential, and they are usually found incidentally. Clinical symptoms are nonspecific. Rarely, appendiceal mucinous neoplasm causes bowel obstruction and makes diagnosis more difficult. We present a case of an 84-year-old female who came to our emergency department having had abdominal fullness and constipation for 5 days. Ileus, due to an affected adhesion band, was diagnosed initially, and symptoms improved gradually under conservative treatment. However, 3 months later she presented to the emergency department again with abdominal pain and distension; small bowel obstruction due to adhesion was again diagnosed. Recurrent bowel obstruction prompted emergent surgery. Operative findings showed a whitish appendiceal tumor adhering to and directly invading the adjacent ileum, with a segment of herniated small bowel wedged in between, causing the obstruction. Upon reviewing the initial computed tomography scan, the dilated tubular structure of appendiceal tumor was misrecognized as small bowel loop; there was no surrounding inflammatory sign, leading to diagnosis difficulty. Instead of a common cause of bowel obstruction, such as adhesion band, this case revealed bowel obstruction can be caused by the direct invasion of an appendiceal tumor. Awareness of this condition with careful image evaluation of small bowel obstruction is essential for diagnosis.

Appendiceal Mucinous Neoplasm in Fourth Decade of Life. Report of a Case

Appendiceal Mucinous Neoplasm in Fourth Decade of Life. Report of a Case

Conditional Survival Following Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Surface Malignancies: An Analysis from the US HIPEC Collaborative.

The long-term prognosis of patients who undergo cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancies (PSM) varies considerably on the basis of histological and operative factors. While overall survival (OS) estimates are used to inform adjuvant therapy and surveillance strategies, conditional survival may provide more clinically relevant estimates of prognosis by accounting for disease-free time elapsed. All patients from 12 academic institutions who underwent CRS ± HIPEC for PSM from 2000 to 2017 were retrospectively analyzed. OS and disease-free survival (DFS) rates were calculated using the Kaplan-Meier method while conditional overall (COS) and conditional disease-free survival (CDFS) rates were calculated at 1, 2, or 3years from surgery for different tumor histologies. Overall, 1610 patients underwent CRS ± HIPEC. Among patients with benign appendiceal mucinous tumors (N = 460), 5-year OS and COS at 3years were 92.1% and 96.3% (Δ4.2%), respectively. For patients with well-differentiated appendiceal cancers (N = 400), 5-year OS and COS at 3years were 76.3% and 88.3% (Δ12.0%), respectively. For patients with high-grade appendiceal cancers (N = 258), 5-year OS and COS at 3years were 43.8% and 75.4% (Δ31.6%), respectively. For patients with colorectal cancers (N = 362), 5-year OS and COS at 3years were 31.8% and 67.3% (Δ35.5%), respectively. For patients with peritoneal mesothelioma (N = 130), 5-year OS and COS at 3years were 67.6% and 89.7% (Δ22.1%), respectively. Similar trends were observed for DFS/CDFS. The conditional survival of patients undergoing CRS ± HIPEC for PSM is associated with tumor histology. COS and CDFS provide a more accurate, dynamic estimate of survival than OS and DFS, especially for patients with more aggressive histologies.

Low–Grade Appendiceal Mucinous Neoplasia: A Rare Case Report

Low-grade appendiceal mucinous neoplasms (LAMN) are rarely seen. They are incidentally detected during an appendectomy for appendicitis. Treatment is appendectomy in low-grade appendiceal mucinous neoplasms. Those having adverse features based on the appendix, lymph node metastasis, and tumour size greater than 2 cm, appendectomy with hemicolectomy is done. We present a rare case report of appendiceal neoplasm diagnosed with low-grade appendiceal mucinous neoplasm (LAMN) managed by appendectomy with right hemicolectomy.

Clinicopathological spectrums and prognosis of primary appendiceal adenocarcinoma, goblet cell adenocarcinoma, and low-grade appendiceal mucinous neoplasms

Primary appendiceal adenocarcinoma (APCA), goblet cell adenocarcinoma (GCA), and low/high-grade appendiceal mucinous neoplasms (LAMN/HAMN) are distinct entities with overlapping clinical presentation and histomorphology, leading to diagnostic challenges. We retrospectively reviewed our archived cases between 2010 and 2018 for diagnosis reappraisal and comparative analysis using updated terminology and modern parameters. A total of 87 cases (22 APCA, 40 GCA, and 25 LAMN pT≥3) were included. The entire cohort had 49 women and 38 men with a median age of 59.9 (range 26-88) years. There were no statistically significant differences in age and sex among the three groups. Clinically, patients with GCA were more likely to present with acute appendicitis (65%) and more likely to have appendectomy as initial surgery (68%). Both APCA and GCA were more likely to involve the proximal appendix while LAMN was more likely to involve the distal appendix (p<0.05). All APCAs were associated with mucosal precursor lesions, most commonly tubular, tubulovillous, or villous adenoma, flat LAMN/HAMN-pTis mucinous epithelium, or mixed, which correlated with distinct histomorphology, tumour differentiation, and stage. Although polypoid precursor lesions were rare in GCA, a significant proportion of GCA showed crypt atypia associated with neoplastic cells. Immunohistochemically, APCA had more frequent β-catenin nuclear positivity and loss of SATB2 expression (p<0.05). KRAS mutation was more common in APCA than in GCA (8/11 vs 1/7, p<0.01). We further validated the three-tiered grading system (G1, G2, G3) in GCA, which correlated well with tumour stage and patient survival. APCA had worse progression-free and disease-specific survivals than GCA and LAMN (pT≥3) with the latter being relatively indolent even when perforated with peritoneal spread. Our study is the first comprehensive comparison between all three appendiceal neoplasms. We also describe a spectrum of previously under-recognised crypt atypia in GCA, which should trigger a diligent search for GCA if present.

High-grade appendiceal mucinous neoplasm: Report a case

High-grade appendiceal mucinous neoplasm: Report a case

Appendiceal Mucinous Neoplasm Appearance on NBI Colonoscopy.

Appendiceal Mucinous Neoplasm Appearance on NBI Colonoscopy.

Incomplete cytoreduction with peritoneal metastases from appendiceal mucinous neoplasms.

Complete cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapyis the standard of care for mucinous appendiceal neoplasms with peritoneal metastases. Despite many publications regarding selection factors favoring a complete CRS, incomplete CRS does occur. Patients with an incomplete CRS are the focus of this manuscript. A retrospective analysis of prospective, histologic, and perioperative data was performed. Overall survival was the endpoint for the numerous assessments. Judgments regarding when to and when not to proceed with an incomplete CRS were sought. From a database of 949 patients who underwent an index CRS for appendiceal mucinous neoplasm, 264 patients (27.8%) had an incomplete CRS. The median overall survival was 1.8 years. Low-grade histopathology and absence of tense ascites or bowel obstruction were significantly associated with increased overall survival. More extensive surgery suggested a more favorable outcome. When a surgeon is confronted by a procedure that will inevitably end with an incomplete CRS, a current trend is to close quickly and always avoid complications. Patients with low-grade neoplasms who present in the absence of tense ascites or bowel obstruction may gain years of survival by surgical reduction of tumor burden.

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

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

EP42.10: Synchronous low‐grade appendiceal mucinous neoplasm and mucinous borderline tumour of the ovary mimicking mucocele: a case report

EP42.10: Synchronous low‐grade appendiceal mucinous neoplasm and mucinous borderline tumour of the ovary mimicking mucocele: a case report

Extent of Disease on Visceral Peritoneal Surfaces of Mucinous Appendiceal Neoplasms Controls Survival.

To determine causes of treatment failure of low-grade appendiceal mucinous neoplasms (LAMN). For 3 decades, LAMN have been treated by cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy. This combined treatment has resulted in a large change in the survival of these patients. A retrospective review of a prospectively maintained database was performed. A restricted cohort of patients with only LAMN histology and complete CRS were included in the statistical analysis. Four hundred and fifty patients were available with a median follow-up of 15.3 years (range 10-35 years). The median age was 49.7 and there were 196 males (43.6%). The mean survival was 24.5 years. Extent of parietal peritonectomy, resection of uterus, ovaries and apex of vagina had no impact on survival. Variables that indicated an increased extent of disease on visceral peritoneal surfaces had a significant impact on survival. Early postoperative intraperitoneal chemotherapy with 5-fluorouracil did not augment hyperthermic intraperitoneal chemotherapy (HIPEC). Patients who required reoperation for recurrence or patients with class 4 adverse events had a reduced prognosis. The mean survival of LAMN treated by complete CRS and perioperative chemotherapy was 24.5 years. Extent of disease quantitated on visceral peritoneal surfaces by the extent of visceral resections was the variable associated with treatment failure. Peritonectomy plus HIPEC was able to control disease on parietal peritoneal surfaces. Not only a larger extent of disease but also its location on visceral peritoneal surfaces controlled survival.