Pseudomyxoma Peritonei in a Case of Carcinoma Cervix: Subtle Finding With Implications on Management and Prognosis.

Pseudomyxoma peritonei (PMP) is a well-known entity in gastrointestinal and ovarian tumors of mucinous histology. It has important implications on prognosis depending on whether seen in conjunction with a benign or a malignant tumor. In the current report, we describe a case of PMP in a case of advanced endocervical adenocarcinoma of the cervix which was managed surgically.

Selective Gastrectomy with Knowledge of Gastric Anatomy and Blood Supply are Key to Complete Tumour Removal in Advanced Pseudomyxoma: Single-Centre Experience with 120 Gastrectomies Over 20 Years.

BACKGROUND: The role of gastrectomy to achieve complete cytoreduction (CCR) for pseudomyxoma peritonei (PMP) is controversial due to uncertain risk/benefit ratio. The outcomes of patients who gastrectomy over a twenty-year period in a high-volume unit are reported. METHODS: All patients requiring gastrectomy to achieve CCR for appendiceal PMP between 2000 and 2020 were reviewed. Demographics, disease, operative, complication, and survival data were analysed. The first and second decades were compared. RESULTS: A total of 2148 patients underwent CRS and HIPEC, of which 78% had CCR. Gastrectomy was performed in 7.1%. Median age was 55 years, and 52% were female. Among gastrectomy patients, 94.2% had ≥1 elevated tumour marker, and 18% had high-grade disease. Median PCI was 30, and 30% required subtotal colectomy. Clavien-Dindo III-IV complications occurred in 32%, and 90-day mortality was 1.75%. Median survival was 104 months, and 10-year OS was 47%. Comparing the two decades, total CRS cases almost tripled, with a greater proportion achieving CCR (82.2% vs. 67.8%) but fewer requiring gastrectomy (5.3% vs. 13.5%). In those who had gastrectomy, disease was more advanced (higher PCI, more high-grade disease, more colectomies) in the later period. However, on multivariable analysis, there was no difference in survival between decades. High-grade histology was the only predictor of survival. CONCLUSIONS: Gastrectomy can achieve good long-term survival with low mortality and acceptable morbidity and should not deter surgeons from achieving CCR. However, increasing experience shows CCR can be achieved, preserving the stomach in the majority of cases through careful consideration of the anatomy and gastric blood supply.

The role of multimodality imaging in the selection and management of patients treated with cytoreductive surgery and HIPEC.

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is the mainstay of potentially curative surgical treatment for malignancies that have spread to peritoneal surfaces. This surgical procedure is however associated with high morbidity and appropriate patient selection and planning is therefore essential. Available multimodality imaging techniques include CT with oral and intravenous contrast, MRI including use of dedicated peritoneal protocol and FDG-PET/CT. These used with the correct technique, read by specialist radiologists and discussed under the auspices of a dedicated multidisciplinary team, can help to improve outcomes. We demonstrate that imaging not only provides information about peritoneal disease burden but more importantly want to shift the reader's focus to disease distribution. Our examples highlight how imaging helps avoid futile surgery by identifying patients with disease in unfavourable sites and show the strength and limitations of the various imaging modalities. We share how MR imaging can help identify multifocal and often occult sites including widespread miliary disease. Our examples provide a comprehensive overview demonstrating how imaging can help plan surgery by identifying patients who may need splenic vaccinations, counselling for stoma, egg harvesting and input from surgeons with other specialist expertise greatly increasing likelihood of achieving complete cytoreduction.

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.

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

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

Mucocoele of the appendix.

Introduction: Mucocoele of the appendix occurs in 0.2-0.7% of people in the world without any well-defined clinical symptoms. It occurs when there is an accumulation of mucous in the lumen of the appendix. Case Presentation: We present three cases: a 48-year-old male admitted to the emergency room with a one-day history of right iliac fossa pain. Abdominal examination was suggestive of acute appendicitis. The initial abdominal computerised tomography scan was reported as being unremarkable. At surgery, a firm tumour of the appendix was found, and a limited right hemicolectomy was done. Histopathology confirmed a mucocoele of the appendix with borderline mucinous histology.The second case is a 63-year-old man who presented with a one-year history of abdominal distension and weight loss. Previous abdominal ultrasound was suggestive of liver cirrhosis with significant ascitic fluid. Abdominal magnetic resonance imaging found an appendix mucocoele with infiltration of the omentum and scalloping of the liver surface suggestive of pseudomyxoma peritonei. A percutaneous biopsy of the omental mass confirmed metastatic mucinous adenocarcinoma of the appendix.The third case is a 68-year-old man who, during an annual medical check-up, had an incidental finding of a cystic right iliac fossa mass on ultrasound, confirmed on abdominopelvic computerised tomography scan to be an appendix mucocele. He had laparoscopic appendicectomy. The histopathological diagnosis confirmed a mucinous cystadenoma of the appendix. Conclusion: Preoperative diagnosis of appendiceal mucocoele is difficult and commonly discovered intraoperatively. The prognosis is good for the histologically benign type, but it is poor when malignant or peritoneal lesions are present. Funding: None declared.

Long-term outcomes and survival analysis of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy in patients with pseudomyxoma peritonei at a newly established peritoneal malignancy centre in Japan.

Background: Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is established in the management of pseudomyxoma peritonei (PMP), selected cases of peritoneal mesothelioma, and resectable colorectal or ovarian peritoneal metastases in Western countries. However, the efficacy and feasibility of these techniques are not well established in the Asian population, and little has been reported on long-term survival outcomes for surgically resected PMP patients. Materials and Methods: Retrospective analysis of a prospective database of short- and longer-term outcomes of consecutive patients who underwent CRS and HIPEC for PMP in a newly established peritoneal malignancy unit in Japan between 2010 and 2016. Results: A total of 105 patients underwent CRS and HIPEC and 57 maximal tumor debulking (MTD) for pseudomyxoma peritonei. In the CRS group, the primary tumor was appendiceal in 94 patients (90%) followed by ovarian and colorectal. Major postoperative complications occurred in 22/105 patients (21%) with one in-hospital mortality (0.9%). The 5-year overall and disease-free survival rates for the CRS group were 74.2% and 50.1%, respectively. Multivariate analysis revealed unfavorable histology to be the significant predictor of reduced overall and disease-free survival. Completeness of cytoreduction, CA19-9, and CA125 were also associated with disease-free survival. Conclusions: This is the first report on long-term outcomes and survival analysis of CRS and HIPEC for PMP in the Asian population. CRS and HIPEC can be conducted with reasonable safety and favorable survival in a new center. Complete tumor removal and histological type are the strongest prognostic factors for both overall and disease-free survival.

Clinical Significance of Circulating Tumor Cells in Epithelial Appendiceal Neoplasms with Peritoneal Metastases.

Appendiceal tumors are uncommon and, at times, discovered incidentally during histological examination. The histopathological classification of the disease is complex and has generated some controversy. The analysis of circulating tumor cells can be used for the early detection of metastatic potential. The aim of the present study was to examine the prognostic value of circulating tumor cells in patients with appendiceal tumors and peritoneal metastases. To our knowledge, this is the first study to examine CTCs in appendiceal tumors. We performed a prospective cohort study of consecutive patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy between 2015 and 2019 at a HIPEC referral center. In total, 31 patients were included in the analysis, and circulating tumor cells were detected in 15 patients (48%). CTC positivity was not associated with overall or recurrence-free survival, nor was it correlated with PCI score or histopathological grading. Surprisingly, however, CTCs were found in almost half the patients. The presence or quantities of these cells did not, on their own, predict systemic metastatic potential during the observed time, and they did not appear to significantly correlate with the oncological outcomes recorded.

Pseudomyxoma Peritonei: An Incidental Diagnosis With Atypical Intraoperative Findings Discovered During a Laparoscopic Cholecystectomy.

Although pseudomyxoma peritonei (PMP) classically presents with profuse mucinous ascites within the peritoneal cavity, the physical manifestations of this disease exist on a spectrum, with the possibility of milder forms that lack typical findings. The authors report an indolent case of PMP diagnosed incidentally during workup and treatment for chronic cholecystitis in a 43-year-old male. This presentation of PMP was atypical due to a lack of discernible symptoms as well as uncharacteristic intraoperative findings consisting of numerous omental and pelvic adhesions with only sparse mucinous deposits. This case contributes to the growing understanding of PMP by exploring an uncharacteristic presentation of the disease with the hope that it may assist clinicians in diagnosing those cases of PMP that are more indolent and insidious in nature.

Histopathological Diagnosis of a Case of Mucin-Secreting Adenocarcinoma of the Appendix.

Mucin-secreting adenocarcinoma of the appendix is a very rare, slow-growing, mucin-producing epithelial neoplasm of the appendix. It is usually found accidentally in an appendicectomy specimen with the presentation of acute appendicitis in most patients or when there is a rupture of the primary tumor with the mucin spreading along with the tumor cells in the entire peritoneal cavity. Here we describe a case of low-grade (well-differentiated) mucin-secreting adenocarcinoma in the appendix. A 48-year-old female presented with complaints of abdominal distension with no other complaints of fever, pain, or breathlessness. Carcinoembryonic antigen levels were 44.8 ng/mL. Cytoreduction surgery of bilateral ovaries was done. The final histopathological diagnosis was reported as low-grade (well-differentiated) mucin-secreting adenocarcinoma of the appendix staged at pT4b pNx pM1c. Pseudomyxoma peritonei is a very feared complication and also, at times, the only presenting symptom where there is an accumulation of mucin in the intra-abdominal cavity due to the spread of mucin-secreting cells, which in turn causes an increase in the abdominal girth along with discomfort for the patient. The mainstay of treatment remains cytoreductive surgery along with hyperthermic intraperitoneal chemotherapy.

The 2022 PSOGI International Consensus on HIPEC Regimens for Peritoneal Malignancies: Pseudomyxoma Peritonei.

BACKGROUND: The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) constitutes the established standard of care for pseudomyxoma peritonei patients. However, the role of HIPEC lacks validation through randomized trials, leading to diverse proposed treatment protocols. This consensus seeks to standardize HIPEC regimens and identify research priorities for enhanced clarity. METHODS: The steering committee applied the patient, intervention, comparator, and outcome method to formulate crucial clinical questions. Evaluation of evidence followed the Grading of Recommendations, Assessment, Development, and Evaluation system. Consensus on HIPEC regimens and research priorities was sought through a two-round Delphi process involving international experts. RESULTS: Out of 90 eligible panelists, 71 (79%) participated in both Delphi rounds, resulting in a consensus on six out of seven questions related to HIPEC regimens. An overwhelming 84% positive consensus favored combining HIPEC with CRS, while a 70% weak positive consensus supported HIPEC after incomplete CRS. Specific HIPEC regimens also gained consensus, with 53% supporting Oxaliplatin 200 mg/m2 and 51% favoring the combination of cisplatin (CDDP) associated with mitomycin-C (MMC). High-dose MMC regimens received an 89% positive recommendation. In terms of research priorities, 61% of panelists highlighted the importance of studies comparing HIPEC regimens post CRS. The preferred regimens for such studies were the combination of CDDP/MMC and high-dose MMC. CONCLUSIONS: The consensus recommends the application of HIPEC following CRS based on the available evidence. The combination of CDDP/MMC and high-dose MMC regimens are endorsed for both current clinical practice and future research efforts.

Pseudomyxoma peritonei: The struggle of a lifetime and the hope of a cure - a rare diagnosis with review of the literature.

Pseudomyxoma peritonei is a rare pathological condition characterized by mucinous tumor tissue implants on the peritoneal surface. Although the cause of Pseudomyxoma peritonei has been extensively studied, the prevailing agreement is that it stems from mucinous tumors that occur in the ovaries or appendix. The tumor tissue typically remains localized to the peritoneum and does not exhibit extraperitoneal spread. Patients with Pseudomyxoma peritonei may present with symptoms such as abdominal pain, bloating, loss of appetite, and shortness of breath. Computerized Tomography is commonly used for diagnostic purposes. The treatment of Pseudomyxoma peritonei typically involves surgical evacuation of the tumoral tissue, followed by cytoreduction and Hyperthermic Intraperitoneal Chemotherapy. While effective treatment options are available, some patients may require repeated surgeries over an extended period. This paper reports on a case study of a patient with a history of recurrent Pseudomyxoma peritonei, necessitating multiple surgical interventions over a decade. The paper concludes with a review of the relevant literature.

Progress on immuno-microenvironment and immune-related therapies in patients with pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) is an indolent malignant syndrome. The standard treatment for PMP is cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy (CRS + HIPEC). However, the high recurrence rate and latent clinical symptoms and signs are major obstacles to further improving clinical outcomes. Moreover, patients in advanced stages receive little benefit from CRS + HIPEC due to widespread intraperitoneal metastases. Another challenge in PMP treatment involves the progressive sclerosis of PMP cell-secreted mucus, which is often increased due to activating mutations in the gene coding for guanine nucleotide-binding protein alpha subunit (GNAS). Consequently, the development of other PMP therapies is urgently needed. Several immune-related therapies have shown promise, including the use of bacterium-derived non-specific immunogenic agents, radio-immunotherapeutic agents, and tumor cell-derived neoantigens, but a well-recognized immunotherapy has not been established. In this review the roles of GNAS mutations in the promotion of mucin secretion and disease development are discussed. In addition, the immunologic features of the PMP microenvironment and immune-associated treatments are discussed to summarize the current understanding of key features of the disease and to facilitate the development of immunotherapies.

No Indication for Routine Resection of Surgical Scars during Cytoreductive Surgery and HIPEC.

BACKGROUND: Careful macroscopic assessment of surgical scars is needed to avoid routine scar resection during cytoreductive surgery (CRS) for peritoneal metastases (PM). This study aimed to analyze the correlation between macroscopically suspected and microscopically confirmed scar metastases (SMs), and to analyze the prognostic impact of not undergoing routine scar resection. METHOD: All patients with previous surgery, treated with CRS and hyperthermic intraperitoneal chemotherapy, for colorectal PM or pseudomyxoma peritonei (PMP), at Uppsala University Hospital in 2013-2021, were included. Macroscopic SMs in surgical reports were compared with histopathological analyses. RESULTS: In total, 227 patients were included. Among colorectal PM patients (n = 156), SM was macroscopically suspected in 41 (26%) patients, and 63 (40%) underwent scar resection. SM was confirmed in 19 (30%). Among patients with macroscopic suspicion, 45% had confirmed SM (positive predictive value, PPV). A total of 1 of 23 (4%) patients with no macroscopic suspicion had SM (negative predictive value, NPV = 96%). Among the PMP patients (n = 71), SM was macroscopically suspected in 13 (18%), and 28 (39%) underwent scar resection, of whom 12 (43%) had SM. The PPV was 77%. Occult SM was found in 1 of 14 (NPV = 93%). Not undergoing routine scar resection did not affect recurrence-free survival (RFS, p = 0.2) or overall survival (OS, p = 0.1) in colorectal PM patients or PMP patients (RFS p = 0.7, OS p = 0.7). CONCLUSION: Occult SM is uncommon and scar resection does not affect RFS or OS. Therefore, macroscopically benign-appearing scars can be left without resection, though resection should be performed upon suspicion or uncertainty.

Omental metastases in patients with pseudomyxoma peritonei or colorectal peritoneal metastases - is routine omentectomy justified?

BACKGROUND: The greater omentum is routinely resected during cytoreductive surgery (CRS), but few studies have analyzed the rationale behind this. This study aimed to assess the prevalence of omental metastases (OM) and the correlation between macroscopically suspected and microscopically confirmed OM, in patients with pseudomyxoma peritonei (PMP) or colorectal peritoneal metastases (PM). METHOD: All patients without previous omentectomy, treated with initial CRS and hyperthermic intraperitoneal chemotherapy for PMP or colorectal PM, at Uppsala University Hospital in 2013-2021, were included. Macroscopic OM in surgical reports was compared with histopathological analyses. RESULTS: In all, 276 patients were included. In those with PMP, 112 (98%) underwent omentectomy and 67 (59%) had macroscopic suspicion of OM. In 5 (4%) patients, the surgeon was uncertain. Histopathology confirmed OM in 81 (72%). In patients with macroscopic suspicion, 96% had confirmed OM (positive predictive value, PPV). In patients with no suspicion, 24% had occult OM (negative predictive value, NPV = 76%). In patients with colorectal PM, 156 (96%) underwent omentectomy and 97 (60%) had macroscopic suspicion. For 5 (3%) patients, the surgeon was uncertain. OM was microscopically confirmed in 90 (58%). PPV was 85% and NPV was 89%. The presence of OM was a univariate risk factor for death in PMP (HR 3.62, 95%CI 1.08-12.1) and colorectal PM (HR 1.67, 95%CI 1.07-2.60), but not in multivariate analyses. CONCLUSION: OM was common and there was a high risk of missing occult OM in both PMP and colorectal PM. These results support the practice of routine omentectomy during CRS.

A Review of Pseudomyxoma Peritonei: Insights Into Diagnosis, Management, and Prognosis.

Pseudomyxoma peritonei (PMP) is a rare and complex clinical syndrome characterized by the accumulation of mucinous ascites within the peritoneal cavity, typically associated with mucinous tumours of appendiceal origin. Despite its rarity, PMP poses significant challenges in diagnosis and management due to its indolent yet locally aggressive nature. This comprehensive review provides insights into the diagnosis, management, and prognosis of PMP, synthesizing current evidence and emerging trends in the field. Challenges and opportunities in PMP management are discussed, along with recommendations for clinical practice emphasizing the importance of a multidisciplinary approach and specialized care. Despite ongoing challenges, advances in surgical techniques, perioperative chemotherapy, and emerging therapies offer hope for improved outcomes and quality of life for PMP patients.

Pseudomyxoma peritonei leading to "jelly belly" abdomen: a case report and review of the literature.

BACKGROUND: Pseudomyxoma peritonei is an infrequent condition with a global annual incidence of only one to two cases per million people. Mucinous neoplasms, widespread intraperitoneal implants, and mucinous ascites characterize it. Currently, most clinicians misdiagnose this condition, which leads to delayed management. CASE PRESENTATION: A 44-year-old North Indian female presented with a 1.5-month history of an abdominal lump. Physical examination revealed a sizeable abdominopelvic mass at 36 weeks. Contrast-enhanced computed tomography showed a massive multiloculated right ovarian cystic mass measuring 28 × 23 × 13 cm with mild ascites and elevated carcinoembryonic antigen levels (113.75 ng/ml). A provisional diagnosis of ovarian mucinous neoplasm was made, for which the patient underwent laparotomy. Intraoperatively, there were gross mucinous ascites, along with a large, circumscribed, ruptured right ovarian tumor filled with gelatinous material. The appendicular lump was also filled with mucinous material along with the omentum, ascending colon, right lateral aspect of the rectum, splenic surface, and small bowel mesentery. Cytoreductive surgery was performed along with an oncosurgeon, including total abdominal hysterectomy with bilateral salpingoophorectomy, omentectomy, right hemicolectomy, lower anterior resection, ileo-transverse stapled anastomosis with proximal ileal loop diversion stoma, excision of multiple peritoneal gelatinous implants, and peritoneal lavage. Histopathology and immunohistochemistry confirmed the presence of intestinal-type mucinous carcinoma. Postoperatively, the patient was given six cycles of chemotherapy. She tolerated it without any specific morbidity and had an uneventful recovery. Postoperative follow-up at 15 months revealed normal tumor marker levels and abdominal computed tomography findings and no signs suggestive of local recurrence or distal metastases. CONCLUSIONS: Pseudomyxoma peritonei is a rare disease that is frequently misdiagnosed in the preoperative phase. Therefore, radiologists and clinicians should maintain a high index of suspicion for accurate diagnosis and multidisciplinary management.

Extra-abdominal growth of a large low-grade appendiceal mucinous tumour through the femoral canal-a rare case report.

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare and heterogeneous diseases that, despite their increased incidence, are well differentiated, tend to be painless, and histologically lack distinctive invasive features without infiltrative growth, destructive infiltration, or associated pro-fibroproliferative responses. However, the biological behaviour of these tumours is difficult to determine preoperatively or intraoperatively, and the possibility of rupture puts patients at risk for peritoneal pseudomucinous neoplasms (PMPs).Patients with low-grade appendiceal mucinous tumours and peritoneal pseudomucinous tumours experience slow disease progression and are incurable and have a high risk of recurrence, morbidity, and ultimately death, despite the reported 5- and 10-year survival rates of 50-86% and 45-68%, respectively. In this article, we report the case of a 80-year-old male with a giant low-grade appendiceal mucinous tumour associated with a peritoneal pseudomucinous tumour, and discuss the diagnostic and management strategies for giant low-grade appendiceal mucinous tumours in the context of a literature review.

Beyond boundaries: Feasibility of curved linear array echoendoscope in appendiceal neoplasm detection.

We recently read with great interest a study by Zhang et al in the World Journal of Gastroenterology. In our practice, we focus specifically on examining appendiceal mucinous neoplasms (AMNs) with endoscopic ultrasound (EUS) using different scopes. AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix. Clinically, they can present as nonspecific acute appendicitis. AMNs can turn into a life-threatening condition, termed pseudomyxoma peritonei, in which the ruptured appendix causes accumulation of mucin in the abdomen. Therefore, accurate and rapid diagnosis of AMN is essential. EUS is able to confirm and stage AMNs; although, EUS examination was once limited to the rectal and anal regions due to the conventional oblique-view scopes. With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes, the scope of examination is changing. Herein, we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.

Recurrence and metastasis of pseudomyxoma peritonei: A rare case report.

Pseudomyxoma peritonei (PMP) is a relatively uncommon condition primarily associated with neoplasms of the appendiceal epithelium. It is characterized by non-specific clinical manifestations, leading to a high rate of misdiagnosis. This report describes the case of a 62-year-old male patient with recurrent and metastatic PMP. The patient first experienced unexplained epigastric pain and paroxysmal abdominal pain accompanied by distension over 8 years ago. He underwent surgical interventions for the condition in other hospitals in 2015 and 2018, respectively.