Low-grade Appendiceal Mucinous Neoplasm Research Articles

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

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

Diagnostic pitfalls in low grade appendiceal mucinous neoplasms

Primary neoplasms of the appendix are present in less than 2% of appendicectomy specimens. Appendiceal mucinous neoplasm is a rare malignancy which is found in less than 0.3% of appendicectomy specimens and accounts for around 1% of gastrointestinal neoplasms. These have varying malignant potential and include a heterogeneous group of diseases. According to the WHO 5th edition (2019), the neoplastic spectrum of appendiceal mucinous neoplasms comprise of low-grade appendiceal mucinous neoplasms (LAMNs), high grade appendiceal mucinous neoplasms (HAMNs), and mucinous adenocarcinoma of the appendix. The patients with mucinous appendiceal lesions are frequently operated for symptoms resembling acute appendicitis as they lack specific clinical and imaging presentation. Categorisation of these neoplasms with attention to extent of mucin and neoplastic cells is crucial to stage the disease as well as to assess the risk of pseudomyxoma peritonei (PMP), a life threatening complication with poor prognosis. We present 8 LAMNs including a rare case of synchronous mucinous cystadenoma of ovary and LAMNs. We discuss the different clinical presentations and the challenges faced in diagnosis.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: Long term oncologic outcomes from the international PSOGI registry

The laparoscopic approach for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (L-CRS + HIPEC) in highly selected patients was previously reported from the PSOGI registry with a demonstrable reduction in length of stay and post-operative morbidity. This study aims to update this international PSOGI registry with a larger cohort of patients and a longer follow-up period. MethodsAn international registry was designed through a networking database (REDCAP®). All centers performing L-CRS + HIPEC were invited through PSOGI to submit data on their cases. Variables such as demographics, clinical outcomes, and survival were analyzed. ResultsA total of 315 L-CRS + HIPEC cases were provided by 14 worldwide centers. A total of 215 patients were included in the L-CRS + HIPEC group. The median peritoneal cancer index (PCI) was 3 (3–5). The median length of stay was 7 days (5-10) and the major morbidity (Clavien-Dindo ≥3) was 6.1% after 30 days. The 5-year disease-free survival (DFS) per tumor origin was: 94% for PMP-LG, 85% for PMP-HG, 100% for benign multicyst peritoneal mesothelioma (MPM), 37.4% for colonic origin, and 54%(at 3 years) for ovarian origin. The 5 years overall survival (OS) per tumor origin was: 100% for PMP-LG, PMP-HG and MPM; 61% for colonic origin, and 74% (at 3 years) for ovarian origin.In addition, a total of 85 patients were analyzed in the laparoscopic risk-reducing HIPEC (L-RR + HIPEC). The median length of stay was 5 days (4–6) and the major morbidity was 6% after 30 days. The 5-year DFS per tumor origin was: 96% for perforated low grade appendiceal mucinous neoplasm (LAMN II) and 68.1% for colon origin. The 5 years OS per tumor origin was: 98% for LAMN II and 83.5% for colonic origin. ConclusionsMinimally invasive CRS + HIPEC is a safe procedure for selected patients with peritoneal carcinomatosis in specialized centers. It improves perioperative results while providing satisfactory oncologic outcomes. L-RR + HIPEC represents a promising strategy that could be evaluated in patients with high risk of developing peritoneal carcinomatosis into prospective randomized trials.

Intraoperative predictors of appendiceal abnormalities in patients with mucinous ovarian neoplasms.

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

Mucinous tumors of the peritoneum

Disseminated peritoneal seeding of mucin-forming tumors is arare malignant disease with variable prognosis. Histomorphological criteria are instrumental in the prognostic assessment. The past 10years have led to astandardization of nomenclature and subsequently to the establishment of therapeutic standards. This article aims to provide the current status of the pathological classification, staging, and grading. Selective literature search in PubMed and Medline RESULTS: The vast majority of disseminated peritoneal mucinous diseases that correspond to the clinical presentation of pseudomyxoma peritonei (PMP) arise from mucinous tumors of the vermiform appendix. Here are to be distinguished: 1)low-grade appendiceal mucinous neoplasms (LAMN), 2)(very rare) high-grade appendiceal mucinous neoplasms (HAMN), 3)mucinous adenocarcinoma without signet ring cells (G2) and 4)mucinous adenocarcinoma with signet ring cells or signet ring cell carcinoma (G3). Other primary tumors only rarely induce PMP. Terms such as mucocele or mucinous cystadenoma of the appendix correspond to LAMN and should no longer be used. Prognostic distinctions are further made between low-grade PMP, which usually arises from LAMN, and the prognostically less favorable high-grade PMP, which usually arises from mucinous/signet ring cell adenocarcinoma or the rare HAMN. Disseminated peritoneal mucinous disease/PMP must then be further distinguished from prognostically excellent local mucin formation of the peri-appendix region. The currently valid nomenclature, as it has emerged from consensus meetings and in parts has also found its way into the current WHO 2019, has significantly contributed to the fact that the prognosis of patients today can be better estimated and effective forms of treatment could be developed.

Oral administration of bromelain and acetylcysteine in pseudomyxoma peritonei (PMP) caused by low-grade appendiceal mucinous neoplasm (LAMN): a case report

BackgroundPseudomyxoma Peritonei (PMP) is a severe neoplastic clinical syndrome characterised by secretion of mucin from tumors often originating in the appendix. The standard treatment includes cytoreductive surgery (CRS) combined with heated intraperitoneal chemotherapy (HIPEC). A new perspective in PMP treatment aims at the mucins themselves as a therapeutic target.Case presentationHere we report the first case of PMP with peritoneal dissemination of mucinous implants caused by low-grade appendiceal mucinous neoplasm (LAMN) in a 58-year-old white male exclusively treated by appendectomy and oral administration of bromelain and acetylcysteine in the context of a medical self-experimentation (by co-author T.R.). Observation so far covers a period of 48 months including regular magnetic resonance imaging (MRI) with stable findings.ConclusionsOral administration of bromelain and acetylcysteine can be used in the treatment of PMP caused by LAMN without relevant clinical side effects.

Incidental finding of appendiceal mucinous neoplasms

Low-grade appendiceal mucinous neoplasms (LAMN) are rare and are diagnosed in at least 0.13% of appendectomies in Germany, although significant underreporting is likely. Perforation of the tumors can result in abdominal mucinous collections, so-called pseudomyxoma peritonei (PMP). The challenge in the treatment of LAMN is the adequate approach to the incidental finding of these tumors. If a mucinous neoplasm is preoperatively suspected in cases of an acute condition, usually appendicitis, it must be weighed up whether aconservative approach is justifiable or whether immediate appendectomy is necessary. If this is the case, an intraoperative perforation of the appendix must be avoided and the complete abdominal cavity must be inspected for mucin deposits. If conservative treatment is possible, further treatment should take place at aspecialized center. If the neoplasm is first found incidentally during surgery, perforation of the appendix should also be avoided and the entire abdominal cavity should be inspected for aPMP. If a PMP is present cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) should be performed in a specialized center. If LAMN are found during the postoperative histological work-up, it should be evaluated whether aperforation was present and mucin collections are noted in the surgical report. In the case of LAMN without evidence of a PMP, appendectomy is the adequate treatment. In cases of intra-abdominal mucinous collections, samples should be taken and further treatment should be performed at a center with sufficient expertise. An ileocecal resection or oncological hemicolectomy is not indicated. After adequate treatment, all patients should receive a follow-up using cross-sectional imaging (preferably magnetic resonance imaging, MRI) and determination of the tumor markers CEA, CA 19-9 and CA 125.

Survival outcomes used to validate version 9 of the American Joint Committee on Cancer staging system for appendiceal cancer.

The standard for cancer staging in the United States for all cancer sites, including primary carcinomas of the appendix, is the American Joint Committee on Cancer (AJCC) staging system. AJCC staging criteria undergo periodic revisions, led by a panel of site-specific experts, to maintain contemporary staging definitions through the evaluation of new evidence. Since its last revision, the AJCC has restructured its processes to include prospectively collected data because large data sets have become increasingly robust and available over time. Thus survival analyses using AJCC eighth edition staging criteria were used to inform stage group revisions in the version 9 AJCC staging system, including appendiceal cancer. Although the current AJCC staging definitions were maintained for appendiceal cancer, incorporating survival analysis into the version 9 staging system provided unique insight into the clinical challenges in staging rare malignancies. This article highlights the critical clinical components of the now published version 9 AJCC staging system for appendix cancer, which (1) justified the separation of three different histologies (non-mucinous, mucinous, signet-ring cell) in terms of prognostic variance, (2) demonstrated the clinical implications and challenges in staging heterogeneous and rare tumors, and (3) emphasized the influence of data limitations on survival analysis for low-grade appendiceal mucinous neoplasms.

Systemic Chemo in Patients With Appendix Adenocarcinoma

Systemic Chemo in Patients With Appendix Adenocarcinoma

Appendiceal collision tumors: case reports, management and literature review.

Appendiceal tumors are incidentally detected in 0.5% cases of appendectomy for acute appendicitis and occur in approximately 1% of all appendectomies. Here, we report two cases of appendiceal collision tumors in two asymptomatic women. In both cases, imaging revealed right-lower-quadrant abdominal masses, which were laparoscopically resected. In both cases, histological examinations revealed an appendiceal collision tumor comprising a low-grade appendiceal mucinous neoplasm and well-differentiated neuroendocrine neoplasm (NEN). For complete oncological control, right hemicolectomy was performed in one patient for the aggressive behavior of NEN; however, histology revealed no metastasis. The other patient only underwent appendectomy. No further treatment was recommended. According to the latest guidelines, exact pathology needs to be defined. Proper management indicated by a multidisciplinary team is fundamental.

Phase 1 study of indenoisoquinoline LMP744 in adults with relapsed solid tumors and lymphomas.

3022 Background: Indenoisoquinolines (IIQ) are non-camptothecin inhibitors of topoisomerase 1 (TOP1) that have improved characteristics over camptothecin TOP1 inhibitors. IIQs demonstrate better chemical stability, produce more persistent DNA breaks induced by trapping DNA-TOP1 cleavage complexes, induce DNA breaks at different sites than camptothecins, and are not substrates for cellular export proteins. We present data from a trial of LMP744 (NSC 706744), which was the most efficacious IIQ in a canine lymphoma trial, designed to establish the safety, efficacy, and maximum tolerated dose (MTD) of LMP744. Methods: We conducted a multicenter phase 1 trial in adult patients (pts) with dose escalations following design 3 of the Simon accelerated titration designs. LMP744 was administered intravenously daily on d1-5 in 28-day cycles (C), starting at dose level (DL) 1 (6 mg/m2/d). Responses and adverse events (AEs) were defined by RECIST 1.1 and CTCAE v4.0, respectively. Plasma concentrations were determined by LC-MS/MS with a validated assay over a range of 1-3,000 ng/mL. Paired biopsies (baseline and C1D2) were analyzed for DNA damage response markers (γH2AX, pNBS1, and Rad51) by IFA. Results: A total of 36 pts were enrolled, median age was 61 years (range 35-81), median prior lines of systemic treatment was 5 (range 2-10) and 26 pts (72%) had received prior TOP1 inhibitor therapy. One pt on DL6 (190 mg/m2/d) experienced a dose-limiting toxicity (DLT) of grade 3 hypokalemia during C1, reverting the study to a 3+3 design. MTD was established at DL6. Of 24 patients evaluable for response, 1 pt with small cell lung cancer on DL6 achieved a partial response (PR), remaining on treatment for 7C. 17 pts had stable disease (including 1 pt with an unconfirmed PR), and 6 had progressive disease. Median duration of response among pts with SD was 4.5C (range 1-28). A total of 6 pts on DL6 with colorectal cancer (n=4, all had received prior irinotecan), mesothelioma (n=1), and low-grade appendiceal mucinous neoplasm (n=1) remained on study for >6C. Treatment-related grade 3/4 AEs included leukopenia (n=9), anemia (n=4), dehydration (n=2), neutropenia (n=2) and nausea (n=2). Pharmacokinetic (PK) data for the first 17 patients suggests dose-linear PK, best fit to a 2-compartment model. Approximate half-life, clearance, central and peripheral volume values were 30 h, 90 L/h, 200 L, and 2500 L, respectively. Induction of γH2AX and Rad51 was measured in the pt with PR. Conclusions: The MTD of LMP744 was established at 190 mg/m2/d on d1-5 in a 28d C. The single agent activity of LMP744 in this heavily pretreated population was limited; however, 4 colorectal cancer pts had prolonged stabilization of disease with prior progression on irinotecan. Analyses of secondary and exploratory correlatives are ongoing. Clinical trial information: NCT03030417 .

Meeting actual benchmarks for short- and long-term outcomes after cytoreductive surgery for peritoneal surface malignancy at a newly established academic treatment center

BackgroundCytoreductive surgery with hyperthermic intraperitoneal chemotherapy is a curative treatment for selected patients with peritoneal surface malignancy. Reaching actual outcomes benchmarks is challenging given the complex nature of peritoneal surface malignancy surgery. The aim of this study was to assess how the benchmarks for morbidity and oncologic outcome can be reached at a newly established program for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. MethodsBuilding on existing institutional experience in complex abdominal surgery and interdisciplinary ovarian cancer treatment, a peritoneal surface malignancy center for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy was established at the Medical University of Vienna using a structured mentoring process. This is a retrospective analysis of the first 100 consecutive patients. Morbidity and mortality were assessed using the Clavien-Dindo classification, and oncologic outcomes using overall survival. ResultsMajor morbidity and mortality were 26% and 3%, and median overall survival was 49.0 months. In patients with colorectal peritoneal metastases, the median overall survival was 35.1 months (all colorectal peritoneal metastases patients) and 48.8 months in the subgroup with Peritoneal Surface Disease Severity Score ≤3. No median overall survival could be calculated in patients with low-grade appendiceal mucinous neoplasms, appendiceal adenocarcinoma, or peritoneal mesothelioma due to >50% of patients being alive at the end of follow-up. ConclusionWe show that the current morbidity and oncological outcomes benchmarks can be reached within the first 100 cases of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a newly established peritoneal surface malignancy center. Previous institutional experience in complex abdominal surgery and a structured mentoring process are key factors in achieving this goal.

ASO Author Reflections: Contemporary Management of Low-Grade Appendiceal Mucinous Neoplasms.

ASO Author Reflections: Contemporary Management of Low-Grade Appendiceal Mucinous Neoplasms.

Various facets of low-grade appendiceal mucinous neoplasms (LAMNs)

Low-grade appendiceal mucinous neoplasms are rare tumors of the appendix that affect women and men equally from the fifth decade of life. They are characterized by the replacement of normal appendiceal mucosal tissue with villous proliferations of mucinous epithelium. The tumor cells secrete mucin, which accumulates in intracytoplasmic vacuoles. Tumor growth occurs by pushing mechanisms without invasion, invasion defining adenocarcinomas. In the early stages, these tumors have low risk of recurrence and are not life-threatening, appendectomy being sufficient for cure. Sometimes, the accumulation of mucin produces ruptures of the appendiceal wall, which may seed tumor content outside the appendix, complicating diagnosis and prognosis, presenting a high risk of recurrence and, in the case of pseudomyxoma peritonei, becoming disabling and life-threatening. For these, treatment becomes more complex, with decreased survival rate.

A Novel Assessment of Metabolic Pathways in Peritoneal Metastases from Low-Grade Appendiceal Mucinous Neoplasms.

There is a paucity of targeted therapies for patients with pseudomyxoma peritonei (PMP) secondary to low-grade appendiceal mucinous neoplasms (LAMNs). Dysregulated metabolism has emerged as a hallmark of cancer, and the relationship of metabolomics and cancer is an area of active scientific exploration. We sought to characterize phenotypic differences found in peritoneal metastases (PM) derived from LAMN versus adenocarcinoma. Tumors were washed with phosphate-buffered saline (PBS), microdissected, then dissociated in ice-cold methanol dried and reconstituted in pyridine. Samples were derivatized in tert-butyldimethylsilyl (TBDMS) and subjected to gas chromatography-coupled mass spectrometry. Metabolites were assessed based on a standard library. RNA sequencing was performed, with pathway and network analyses on differentially expressed genes. Eight peritoneal tumor samples were obtained and analyzed: LAMNs (4), and moderate to poorly differentiated adenocarcinoma (colon [1], appendix [3]). Decreases in pyroglutamate, fumarate, and cysteine in PM from LAMNs were found compared with adenocarcinoma. Analyses showed the differential gene expression was dominated by the prevalence of metabolic pathways, particularly lipid metabolism. The gene retinol saturase (RETSAT), downregulated by LAMN, was involved in the multiple metabolic pathways that involve lipids. Using network mapping, we found IL1B signaling to be a potential top-level modulation candidate. Distinct metabolic signatures may exist for PM from LAMN versus adenocarcinoma. A multitude of genes are differentially regulated, many of which are involved in metabolic pathways. Additional research is needed to identify the significance and applicability of targeting metabolic pathways in the potential development of novel therapeutics for these challenging tumors.

A case report of low-grade appendiceal mucinous neoplasm in perforated appendicitis: literature review, acute surgery and later additional HIPEC treatment to prevent pseudomixoma peritonei

Low-grade appendiceal mucinous neoplasm (LAMN) accounts less than 0.5% of all gastrointestinal neoplasm. Early stage AMNs are usually incidentally diagnosed on a surgical specimen after appendectomy for acute appendicitis. In this study, we reported a 42-year-old female presented complaining right lower abdominal pain for 3 days. Abdominal US revealed inflamed appendix surrounded by ipo-anechoic area of 3 cm, with increased thickness of near ileus. Intraoperatively a fistula between appendix and terminal ileum was found; for that reason, a right hemicolectomy was performed. Histopathology indicated a low-grade appendiceal mucinous neoplasms (LAMNs). Four months later the patient underwent hyperthermic intraperitoneal chemotherapy (HIPEC) with C-mitomycin and Cisplatin and was followed up for 6 months with no disease progression, confirmed by CT scan. At present there is not a consensus about LAMNs treatment, due to the scarcity of cases. Consensus statement of the Peritoneal Surface Oncology Group published in 2020 seems to be the best guideline available nowadays; Recommendations are provided based on three Delphi voting rounds with GRADE-based questions amongst a panel of 80 worldwide PMP experts. Given the rarity of these pathologies, each clinical case and longer follow up are important. Appropriate surgery-based treatment followed by HIPEC could contribute to the improvement of prognosis and severe outcomes among these patients. In our opinion patients affected by LAMN should receive prophylactic HIPEC treatment in order to achieve the greatest survival benefit even if they run the risk of overtreatment.

Incidental Detection of Low-Grade Appendiceal Mucinous Neoplasm

Incidental Detection of Low-Grade Appendiceal Mucinous Neoplasm

Mucinous tumors arising from ovarian teratomas as another source of pseudomyxoma peritoneii: MR findings comparison with ovarian metastases from appendiceal mucinous tumors.

The origin of pseudomyxoma peritoneii (PMP) has been established as low-grade appendiceal mucinous tumors (AMT). However, intestinal-type ovarian mucinous tumors are known as another source of PMP. Recently, it is advocated that ovarian mucinous tumors causing PMP originates from teratomas. However, AMTs are often too small to detect on imaging; then, differentiating metastatic ovarian tumors of AMT from ovarian teratoma-associated mucinous tumors (OTAMT) is important. Therefore, this study investigates the MR characteristics of OTAMT compared to the ovarian metastasis of AMT. MR findings of six pathologically confirmed OTAMT were retrospectively analyzed compared to ovarian metastases of low-grade appendiceal mucinous neoplasms (LAMN). We studied the existence of PMP, uni- or bilateral disease, the maximum diameter of ovarian masses, the number of loculi, a variety of sizes and signal intensity of each content, the existence of the solid part, fat, calcification within the mass, and appendiceal diameters. All the findings were statistically analyzed using the Mann-Whitney test. Four of the six OTAMT showed PMP. OTAMT showed unilateral disease, had a larger diameter, more frequent intratumoral fat, smaller appendiceal diameter than those in AMT, and they were statistically significant (p < .05). On the other hand, the number, variety of size, signal intensity of loculi, and the solid part, calcification within the mass did not differ from each other. Both OTAMT and ovarian metastasis of AMT appeared as multilocular cystic masses with relatively uniform signal and size of loculi. However, a larger unilateral disease with intratumoral fat and smaller size of the appendix may suggest OTAMT. OTAMT can be another source of PMP, as AMT. MR characteristics of OTAMT were very similar to ovarian metastases of AMT; however, in cases with PMP combined with fat-containing multilocular cystic ovarian mass, we can diagnose them as OTAMT, not PMP caused by AMT.

Imaging Recommendations for Diagnosis, Staging, and Management of Peritoneal Malignancies

AbstractPeritoneum is a serosal membrane lining the solid viscera and the hollow viscus of the abdomen and is made of a single layer of mesothelial cells. The most common primaries that spread to the peritoneum include gastrointestinal, ovarian, colorectal, and peritoneal metastases can be seen at some point during the disease course in 15 to 43%, 60 to 70% and 15 to 20% of patients, respectively. Other malignancies involving the peritoneum such as primary peritoneal carcinoma, peritoneal mesothelioma, peritoneal lymphomatosis, pseudomyxoma peritonei from low-grade appendiceal mucinous neoplasm, are far less common. The review strives to provide a framework for diagnosis and management of the disease.

A rare case of low-grade appendiceal mucinous neoplasm with serosal involvement: a case report

Low-grade appendiceal mucinous neoplasm (LAMN) is a malignant lesion of the appendix with an unknown etiology. It is a rare occurrence and incidental finding with only a few cases documented in literature. We present the case of a 55-year-old male with a 5-day history of diffuse abdominal pain, which then localized to the right lower quadrant (RLQ). Abdominal imaging revealed a soft tissue mass in and around the appendix, eventually leading to the diagnosis of a mucinous tumor. Exploratory laparotomy revealed a mucinous tumor of the appendix with rupture. Appendectomy was performed and the specimen along with the mucinous material was submitted for histology. Histopathological examination confirmed the diagnosis of LAMN with serosal perforation. Postoperatively the patient is stable and doing well on follow up. The patient was referred to oncology for further management. Although, LAMN is rare, there is a lack of standardization of treatment, with the need for development to prevent the latter complication of the ill-fated outcome, pseudomyxoma peritonei (PMP).