Search

Abstract Background PMP is a rare clinical syndrome characterized by the accumulation of mucinous material in the peritoneal cavity. The combination of CRS and HIPEC is the standard treatment, known to improve survival outcomes. However, follow-up adherence is critical for early detection of recurrence and extending survival. This study is the first to specifically investigate postoperative follow-up adherence in PMP patients treated with CRS and HIPEC. Aims To explore the socio-demographic and clinical determinants of follow-up adherence and its impact on survival in PMP patients treated with CRS and HIPEC. Methods This single-center, six-year retrospective study included 111 PMP patients who underwent CRS and HIPEC. Patients were categorized into compliant (control) and non-compliant (study) groups. Follow-up was initiated by the physician, with patients returning for regular visits as recommended. Kaplan-Meier analysis was used to evaluate survival outcomes, while univariate analysis identified factors influencing follow-up adherence. Results Among 111 patients, 32 died by August 2024, with 1-, 3-, and 5-year survival rates of 88%, 66%, and 53%, respectively. High PCI scores (P

Background: PMP is a rare clinical syndrome characterized by the accumulation of mucinous material in the peritoneal cavity. The combination of CRS and HIPEC is the standard treatment, known to improve survival outcomes. However, follow-up adherence is critical for early detection of recurrence and extending survival. This study is the first to specifically investigate postoperative follow-up adherence in PMP patients treated with CRS and HIPEC. Aims: To explore the socio-demographic and clinical determinants of follow-up adherence and its impact on survival in PMP patients treated with CRS and HIPEC. Methods: This single-center, six-year retrospective study included 111 PMP patients who underwent CRS and HIPEC. Patients were categorized into compliant (control) and non-compliant (study) groups. Follow-up was initiated by the physician, with patients returning for regular visits as recommended. Kaplan-Meier analysis was used to evaluate survival outcomes, while univariate analysis identified factors influencing follow-up adherence. Results: Among 111 patients, 32 died by August 2024, with 1-, 3-, and 5-year survival rates of 88%, 66%, and 53%, respectively. High PCI scores (P < 0.001) and poorer histopathological types (P = 0.002) were significant predictors of reduced survival. Non-compliance with follow-up showed a trend toward decreased survival (P = 0.07). Significant risk factors for non-compliance included lower ASA scores (P = 0.020), middle- and low-income levels (P = 0.034), and parental survival status (P = 0.003). Middle- and low-income patients also experienced longer delays in seeking medical advice and had fewer cases detected through routine health screenings (P = 0.019). Conclusions: Follow-up compliance has a potential impact on survival outcomes in PMP patients treated with CRS and HIPEC. Socio-demographic factors significantly influence adherence, highlighting the need for tailored interventions to enhance patient management. [ABSTRACT FROM AUTHOR]

Background: Pseudomyxoma peritonei (PMP) is a clinical entity of subtle onset abdominal pain, ascites, and distention associated with characteristic imaging. In most cases, laparoscopic exploration will give the definitive diagnosis and histopathologic verification. However, usually there are difficulties in the diagnosis of this disease. Case Report: Herein, we present a case of a 51-year-old female who developed ascites over 5 months. An investigational laparotomy established the diagnosis of PMP, after the discovery of a mucinous, grey-brown tumor that was CK20 positive and CK7 negative. Subsequently, chemotherapy with oxaliplatin combined with 5-FU (FOLFOX4 regimen), was initiated and the patient survived for 30 months. We also present a comprehensive review of the English literature concerning the different symptoms and radiological findings of this rare entity. According to the literature review, 35 cases of PMP with different clinical and radiological findings have been described. In the majority of the cases, ultrasound, computed tomography or magnetic resonance imaging was orientating towards a proper diagnosis before a diagnostic laparotomy. Conclusion: The combination of a clinical picture with the characteristic imaging findings enables a prompt diagnosis of PMP, making prognosis more favorable. [ABSTRACT FROM AUTHOR]

Abstract Introduction Pseudomyxoma peritonei (PMP) is a generalized term, usually known as “jelly belly” since 1884. Incidence is very low, 1–3 per million people per year. Because of its indolent nature, it is usually diagnosed at an advanced stage, thereby impacting the quality of life. The 5-year survival rate varies from 23 to 86% in world literature. Even 10 years and 20 years of survival have been described. With our experience, we like to propose rename of PMP as abdomino-peritoneal mucinous carcinoma (APM) as we strongly feel the time has come to specify the term and standardize the management strategy. Methodology In the premier institute of India and as a tertiary referral center, we experienced the maximum number of advanced cases of APM. From 2012 to 2021, we analyzed all the APM patients based on a prospectively maintained computerized database in the department of surgical oncology and found the reasons for renaming from this traditional one. Results We included a total of 87 patients who underwent surgical intervention. Thirty-five patients underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), and 52 patients underwent debulking. In CRS-HIPEC patients, CC-0 was achieved in 28 patients (80%), CC-1 in 4 patients (11.4%), and CC-2 in 3 patients (8.6%). Palliative intent HIPEC was done in 3 patients (8.6%). Clavien-Dindo grade III and IV morbidity was observed in 18.8% of patients with 90 days mortality of 5.7%. Conclusion With our long-term experience and advancement of scientific evidence, we like to propose a new name for PMP as APM. We strongly believe this paper will give a clear picture of this rare disease and standard management outlines.

Introduction: Pseudomyxoma peritonei (PMP) is a generalized term, usually known as "jelly belly" since 1884. Incidence is very low, 1–3 per million people per year. Because of its indolent nature, it is usually diagnosed at an advanced stage, thereby impacting the quality of life. The 5-year survival rate varies from 23 to 86% in world literature. Even 10 years and 20 years of survival have been described. With our experience, we like to propose rename of PMP as abdomino-peritoneal mucinous carcinoma (APM) as we strongly feel the time has come to specify the term and standardize the management strategy. Methodology: In the premier institute of India and as a tertiary referral center, we experienced the maximum number of advanced cases of APM. From 2012 to 2021, we analyzed all the APM patients based on a prospectively maintained computerized database in the department of surgical oncology and found the reasons for renaming from this traditional one. Results: We included a total of 87 patients who underwent surgical intervention. Thirty-five patients underwent cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC), and 52 patients underwent debulking. In CRS-HIPEC patients, CC-0 was achieved in 28 patients (80%), CC-1 in 4 patients (11.4%), and CC-2 in 3 patients (8.6%). Palliative intent HIPEC was done in 3 patients (8.6%). Clavien-Dindo grade III and IV morbidity was observed in 18.8% of patients with 90 days mortality of 5.7%. Conclusion: With our long-term experience and advancement of scientific evidence, we like to propose a new name for PMP as APM. We strongly believe this paper will give a clear picture of this rare disease and standard management outlines. [ABSTRACT FROM AUTHOR]

Fengcai Yan,1,2 Feng Shi,1,2 Xinbao Li,3 Chunkai Yu,1 Yulin Lin,3 Yan Li,1,3 Mulan Jin2 1Department of Pathology, Beijing Shijitan Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Department of Pathology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, People’s Republic of China; 3Department of Peritoneal Cancer Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing, People’s Republic of ChinaCorrespondence: Mulan Jin Email kinmokuran@163.comObjective: This study aims to demonstrate clinicopathological characteristics and immunohistopathological phenotypes of pseudomyxoma peritonei (PMP) originated from ovaries.Methods: The primary origin of PMP was explored by reviewing H&E sections retrospectively and performing a series of immunohistochemical staining on CK7, CK20, CDX2, CEA, Villin, SATB2, CA125, ER, PR, and MUC.Results: Among 310 PMP patients, a few originated from extra-appendix, whereas eight cases were of ovarian origin (2.6%), including three teratoma-associated ovarian mucinous tumors and five primary ovarian mucinous tumors with spontaneous or iatrogenic rupture, respectively. Most peritoneal metastases were acellular mucin or low-grade mucinous carcinoma peritonei (6/8, 75%), while the rest were high-grade mucinous carcinoma peritonei (2/8, 25%). Tumors were positive for CK20, CDX2, CEA, and Villin. SATB2 was specifically diffuse positive in teratoma-associated ovarian mucinous tumors, and negative in primary ovarian mucinous tumors. Differential expression of MUC was observed in these tumors.Conclusion: PMP of ovarian origin is extremely rare. The precise diagnosis requires serial sections of the appendix or suspicious tissue to exclude appendiceal mucinous neoplasms, as well as comprehensive analysis of clinical features, surgical findings, histopathological characteristics, and immunohistochemistry on specific biomarkers.Keywords: pseudomyxoma peritonei, PMP, ovary, mucinous tumor

Background: Pseudomyxoma peritonei (PMP) is a rare clinical condition with fatal outcomes, which is characterized by the progressive accumulation of mucinous ascites and peritoneal implants. Some studies have reported the effect of PMP biology on patient outcome. The objective of this study was to analyze published articles focusing on the impact of pathology on the prognosis of PMP patients undergoing debulking.Methods: Data from all studies regarding the prognosis of patients, with different pathologies, who underwent debulking surgery were analyzed. We searched PubMed, the Wiley Online Library, Ovid, and the Cochrane Library (through January 2020). Studies were confined to those articles written in English. Five studies were identified, and the differences in 5-year survival rates were analyzed according to the Kaplan–Meier survival curves. The hazard ratios (HRs) of the 5-year survival rates were calculated.Results: The mean and median 5-year survival rates of all patients were 39 and 40%, respectively. The median overall survival was 49.3 months. The mean 5-year survival rates of low-grade PMP was 45.2%. The five studies had sufficient data to calculate HRs from the 5-year survival rates data, and three had HRs lower than 1. The total HRs was 0.54, with a 95% CI between 0.33 and 0.89 (P = 0.01).Conclusions: Among PMP patients receiving debulking surgery who are not able to undergo complete cytoreductive surgery, low-grade biological PMP had a better prognosis than high-grade PMP.

Pseudomyxoma peritonei (PMP) arising from an intraductal papillary mucinous neoplasm of the pancreas (IPMN) is a rare condition. The diagnosis of IPMN as the origin of PMP is mainly inferred from the clinical course and the exclusion of PMP from other organs. The pathological diagnosis has not yet been established. To evaluate the usefulness of immunohistochemical staining for the diagnosis of the primary lesion of PMP as IPMN. There are 2 cases of PMP arising from IPMN between March 2010 and December 2019 at National Center for Global Health and Medicine. A PubMed search that reported PMP arising from IPMN identified 16 additional cases. Diagnostic methods and clinicopathological features of 18 cases were compared. Four cases including our two cases used immunohistochemical staining for the diagnosis of PMP arising from IPMN. The correspondence of the immunohistochemical staining between PMP and IPMN was shown in the three cases including previously reported two cases and one of our two cases to identify the primary lesion of PMP as IPMN. In addition, we revealed that the comparison of the immunostaining pattern of PMP with the representative immunostaining pattern of the candidate primary lesions is helpful for the diagnosis of the primary lesion of PMP. Immunohistochemical staining is helpful to identify the primary lesion of PMP as IPMN. [ABSTRACT FROM AUTHOR]

Pseudomyxoma peritonei (PMP) is a subtype of peritoneal carcinomatosis that is traditionally treated by cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC). A growing body of evidence suggests that microbes are associated with various tumor types and have been found in organs and cavities that were once considered sterile. Prior and ongoing research from our consortium of PMP researchers strongly suggests that bacteria are associated with PMP tumors. While the significance of this association is unclear, in our opinion, further research is warranted to understand whether these bacteria contribute to the development, maintenance and/or progression of PMP. Elucidation of a possible causal role for bacteria in PMP could suggest a benefit for supplementation of antibiotics to current treatment protocols. [ABSTRACT FROM AUTHOR]

The epithelial appendiceal neoplasms are uncommon and are usually detected as an unexpected surgical finding. The general surgeon should be aware of the diversity of its clinical manifestations and biological behaviors along with the significance of the surgical treatment on the progression of the illness and the prognosis of the patients. The operative findings and, especially, tumor histology, determine the type of surgery. Intestinal histologic subtype behaves and should be treated similarly to the right colon neoplasms; while mucinous tumors, often discordant between histology and its aggressiveness, can be treated with a simple appendectomy or require complex oncological surgeries. Mucinous tumors are often associated with the presence of mucin or tumor implants in the abdominal cavity, being the clinical syndrome known as pseudomyxoma peritonei (PMP). PMP tends to present an indolent but deadly evolution and requires a multimodal approach as a single treatment with curative potential: complete cytoreductive surgery plus hyperthermic Intra-peritoneal chemotherapy (CCRS + HIPEC) now considered the standard of care in this pathology. The general surgeon should be aware of the governing principles of the treatment of appendiceal neoplasms with or without peritoneal dissemination, know the therapeutic frontiers in every situation (avoiding unnecessary or counterproductive surgeries) and sending early these patients to specialised centres in the radical management of malignant diseases of the peritoneum in the conditions and with the necessary information to facilitate a possible radical treatment. [ABSTRACT FROM AUTHOR]

Background: Peritoneal dissemination of abdominal malignancy (carcinomatosis) has a clinical course marked by bowel obstruction and death; it traditionally does not respond well to systemic therapy and has been approached with nihilism. To treat carcinomatosis, we use cytoreductive surgery (CS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Methods: A prospective database of patients has been maintained since 1992. Patients with biopsy-proven peritoneal surface disease were uniformly evaluated for, and treated with, CS and HIPEC. Patient demographics, performance status (Eastern Cooperative Oncology Group), resection status, and peritoneal surface disease were classified according to primary site. Univariate and multivariate analyses were performed. The experience was divided into quintiles and outcomes compared. Results: Between 1991 and 2013, a total of 1,000 patients underwent 1,097 HIPEC procedures. Mean age was 52.9 years and 53.1% were female. Primary tumor site was appendix in 472 (47.2%), colorectal in 248 (24.8%), mesothelioma in 72 (7.2%), ovary in 69 (6.9%), gastric in 46 (4.6%), and other in 97 (9.7%). Thirty-day mortality rate was 3.8% and median hospital stay was 8 days. Median overall survival was 29.4 months, with a 5-year survival rate of 32.5%. Factors correlating with improved survival on univariate and multivariate analysis (p ≤ 0.0001 for each) were preoperative performance status, primary tumor type, resection status, and experience quintile (p = 0.04). For the 5 quintiles, the 1- and 5-year survival rates, as well as the complete cytoreduction score (R0, R1, R2a) have increased, and transfusions, stoma creations, and complications have all decreased significantly (p < .001 for all). Conclusions: This largest reported single-center experience with CS and HIPEC demonstrates that prognostic factors include primary site, performance status, completeness of resection, and institutional experience. The data show that outcomes have improved over time, with more complete cytoreduction and fewer serious complications, transfusions, and stomas. This was due to better patient selection and increased operative experience. Cytoreductive surgery with HIPEC represents a substantial improvement in outcomes compared with historical series, and shows that meaningful long-term survival is possible for selected carcinomatosis patients. Multi-institutional cooperative trials are needed to refine the use of CS and HIPEC. [Copyright &y& Elsevier]

Background: Pseudomyxoma peritonei (PMP) is a rare malignancy, and many uncertainties regarding its treatment and prognosis still remain. The main treatment for PMP is cytoreductive surgery (CRS) combined with heated intraperitoneal chemotherapy (HIPEC), which can lead to intra-abdominal trauma and systemic reactions. Enteral nutrition (EN) is an important and beneficial perioperative option for major complicated abdominal surgery compared with total parenteral nutrition (TPN). However, the role of EN in PMP after surgery is still unknown. The purpose of this study was to analyze the effects of EN on postoperative outcomes in PMP patients., Methods: The perioperative clinical data of PMP patients from Xiangya Hospital of Central South University who accepted CRS plus HIPEC from January 2011 to December 2018 were collected and analyzed. The effects of EN on the nutritional status, postoperative complications, and hospital stay time of patients with PMP were studied. We further analyzed the risk factors affecting hospital stay and complications in PMP patients after surgery., Results: A total of 51 PMP patients accepted CRS and were enrolled in this study, including 25 cases in the EN group and 26 patients in the TPN group. The baseline demographic characteristics and preoperative nutritional status were not significantly different between the two groups. The postoperative absolute lymphocyte count (P<0.001), hemoglobin (P=0.016), and albumin (P<0.001) levels of the EN group were higher than those of the TPN group, but the postoperative hospital stay time (P=0.008) and the complication rate (P=0.03) in the EN group were less than those in the TPN group. Logistic regression analysis showed that age (P=0.031), American Society of Anesthesiologists (ASA) score (P=0.008), and EN (P=0.024) were independent risk factors for postoperative hospital stay in PMP patients. ASA score (P=0.006), number of prior operations (P=0.021), and EN (P=0.035) were independent risk factors for postoperative complications in PMP patients., Conclusions: EN support results in better outcomes and is an independent protective factor for the postoperative hospital stay time and complications of PMP patients., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-22-170/coif). The authors have no conflicts of interest to declare., (2022 Gland Surgery. All rights reserved.)

Background: Because few studies have focused on the correlation between computed tomography (CT) signs and tumor grade in pseudomyxoma peritonei (PMP), we evaluated predictive value of abdominal enhanced CT in identifying high- vs . low-grade cases., Methods: In all, 75 patients diagnosed with PMP after surgery were consecutively recruited. The preoperative enhanced CT images were retrospectively analyzed for ascites, hepatic scalloping, omental and peritoneal lesion appearance, intralesional calcification and septa, and peripheral organ involvement. Logistic regression models were applied to analyze the relationship of CT signs with PMP grade. Receiver operating characteristic curves were generated to evaluate the potential utility of CT signs in detecting high-grade PMP., Results: Massive ascites (P=0.017) and peritoneal solid nodules (P<0.001) were more common in high-grade cases. Multivariate logistic regression identified massive ascites [odds ratio (OR) =4.389, 95% confidence interval (CI): 1.210-15.921; P=0.025] and peritoneal solid nodules (OR =19.932, 95% CI: 3.560-111.596; P<0.001) as independent predictors of high-grade PMP. For the 55 patients with hepatic scalloping, the maximum thickness of mucin deposition at the hepatic scalloping wave in high-grade PMP was thinner than that in low-grade PMP (P=0.021). Thickness of mucin deposition at the hepatic scalloping wave (OR =0.346, 95% CI: 0.148-0.809; P=0.014) was an independent predictor of high-grade PMP, with a cutoff value of 18.6 mm. Cancer antigen 125 (CA125) combined with CT signs was significantly better at diagnosing high-grade PMP than was CA125 alone in both the overall patients [area under the ROC curve (AUC): 0.812 vs . 0.656; P=0.020] and those with hepatic scalloping (AUC: 0.859 vs . 0.600; P=0.007)., Conclusions: The CT signs of high-grade PMP significantly differ from those of low-grade PMP, and thus combining CT signs with CA125 may be highly valuable for classifying PMP., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-21-976/coif). The authors have no conflicts of interest to declare., (2022 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

Background: Few studies on long-term survival have been published since the new updated pseudomyxoma peritonei (PMP) classification was published in 2016. The aim was to investigate long-term survival according to the Peritoneal Surface Oncology Group International (PSOGI) classification and compare prognostic factors., Methods: From Uppsala University Hospital, consecutive patients referred for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) from 2004 to 2017 with peritoneal disease from non-carcinoid mucinous epithelial appendiceal neoplasms were included in the study. The peritoneal disease was divided into four groups: mucin only, low-grade mucinous carcinoma peritonei (MCP-1), high-grade (MCP-2), and high-grade with signet ring cells (MCP-3). Survival curves were rendered, and prognostic factors were compared., Results: The study included 223 patients: 36 with mucin only, 112 with MCP-1, 70 with MCP-2, and 5 with MCP-3. Thirty-eight patients had a palliative debulking or open/close procedure. The 5- and 10-year overall survival was 97% and 97% for mucin only, 83% and 70% for MCP-1, 69% and 49% for MCP-2, with no patients still under follow-up after 5 years in the MCP-3 group. In a multivariable analysis, completeness of cytoreduction (CC) score 2-3 and PSOGI class MCP-3 were significantly associated with lower survival. The 5-year overall survival in the palliative setting was 40% vs. 44% (MCP-1 vs. MCP-2, P>0.05) with median survival 51 vs. 53 months, respectively., Conclusions: The PSOGI classification of PMP provides a solid differentiation of prognostic groups after CRS/HIPEC treatment, but not in the palliative setting., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jgo.amegroups.com/article/view/10.21037/jgo-21-581/coif). PHC reports unrestricted funding from the Bengt Ihre Fellowship fund which has paid for processing charges and provided time for article drafting. The other authors have no conflicts of interest to declare., (2022 Journal of Gastrointestinal Oncology. All rights reserved.)

Background/aim: While controversial, cytoreductive surgery (CRS) with heated intra-peritoneal chemotherapy (HIPEC) and early postoperative intra-peritoneal chemotherapy (EPIC) remains the mainstay of treatment for low grade appendiceal neoplasm with pseudomyxoma peritonei (PMP). Our study aimed to investigate the difference in survival when administering HIPEC alone vs. HIPEC + EPIC. Additionally, we examined whether the duration of EPIC affects survival., Patients and Methods: We compared the difference in survival in 238 patients who underwent CRS + HIPEC alone vs. CRS + HIPEC/EPIC combination for low grade appendiceal cancer. We also compared short course (1-2 days) vs. long course (3-5 days) of EPIC., Results: HIPEC/EPIC combination group (n=179) showed a significantly better 5-year survival of 95% compared to 71% in HIPEC alone (n=59). There was no statistically significant difference in 5-year survival between short course (n=22) and long course of EPIC (n=157)., Conclusion: Combined use of HIPEC and EPIC improves 5-year survival in low-grade appendiceal neoplasm. Two days of EPIC are sufficient., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Low grade appendiceal mucinous neoplasm (LAMN) is the primary source of pseudomyxoma peritonei (PMP). PMP may develop after seemingly complete resection of primary tumor by appendectomy, which is unpredictable due to lack of reliable prognostic indicators. We retrospectively reviewed 154 surgically resected LAMNs to explore if any of the macroscopic and microscopic characteristics may be associated with increasing risk of PMP development. Our major findings include: (1) As compared to those without PMP, the cases that developed PMP were more frequent to have (a) smaller luminal diameter (<1 cm) and thicker wall, separate mucin aggregations, and microscopic perforation/rupture, all suggestive of luminal mucin leakage; (b) microscopic acellular mucin presenting on serosal surface and not being confined to mucosa; and (c) neoplastic epithelium dissecting outward beyond mucosa, however, with similar frequency of neoplastic cells being present in muscularis propria. (2) Involvement of neoplastic cells or/and acellular mucin at surgical margin did not necessarily lead to tumor recurrence or subsequent PMP, and clear margin did not absolutely prevent PMP development. (3) Coexisting diverticulum, resulted from neoplastic or non-neoplastic mucosa being herniated through muscle-lacking vascular hiatus of appendiceal wall, was seen in a quarter of LAMN cases, regardless of PMP. The diverticular portion of tumor involvement was often the weakest point where rupture occurred. In conclusion, proper evaluation of surgical specimens with search for mucin and neoplastic cells on serosa and for microscopic perforation, which are of prognostic significance, should be emphasized. • Appendectomy specimens containing LAMN with PMP development were more frequent to have (a) smaller luminal diameter (<1 cm) and thicker wall, separate mucin aggregations, and microscopic perforation/rupture, suggestive of luminal mucin leakage. (b) microscopic acellular mucin presenting on serosal surface and not being confined to mucosa; and (c) neoplastic epithelium dissecting outward beyond mucosa, however, with similar frequency of neoplastic cells being present in muscularis propria. • Involvement of neoplastic cells or/and acellular mucin at surgical margin did not necessarily lead to tumor recurrence or subsequent PMP, and clear margin did not absolutely prevent PMP development. • Coexisting diverticulum, resulted from neoplastic or non-neoplastic mucosa being herniated through muscle-lacking vascular hiatus of appendiceal wall, was seen in a quarter of LAMN cases, regardless of PMP. [ABSTRACT FROM AUTHOR]

Pseudomyxoma peritonei is a rare disease with a reported prevalence of about 1-3 per million people annually. Cytoreductive surgery and perioperative hyperthermic intraperitoneal chemotherapy are considered as treatment options improving disease control or long-term survival. However, for patients with incomplete cytoreduction or debulking surgery, outcomes are significantly poorer compared with patients who have obtained complete or optimal cytoreduction. In cases of high-grade pseudomyxoma peritonei that are considered inoperable and/or unresectable, combination chemotherapy regimen with a neo-angiogenesis inhibitor such as bevacizumab is recommended. In this report, a 62-year-old Japanese man presented with abdominal distention. Examination of ascites demonstrated a jelly-like consistency and peritoneal pseudomyxoma was suspected. To relieve progressive symptoms, palliative debulking surgery with total colectomy was performed. Postoperative pathology confirmed high-grade appendiceal mucinous neoplasm with high-grade pseudomyxoma peritonei. In our case, combination chemotherapy with trifluridine/tipiracil (TAS-102) and bevacizumab was initiated after palliative debulking surgery. As a result, carcinoembryonic antigen level was kept stable and the volume of ascites remained almost the same as at the beginning of treatment for more than 2 years. In conclusion, combination chemotherapy comprising TAS-102 and bevacizumab in patients with palliative debulking could be a useful option for patients with high-grade mucinous appendiceal neoplasm and high-grade pseudomyxoma peritonei.

Pathology is central to the management of peritoneal surface malignancy. This article highlights some recent advances that have had an impact on patient management or could do so in the near future. Malignant peritoneal mesothelioma, particularly the epithelioid subtype, is amenable to radical therapy in selected cases, and factors such as ki67 proliferation index, expression of BAP1 and mutation in CDKN2A show promise as prognostic indicators. Our understanding of multicystic mesothelioma has improved in recent years; it is a true neoplasm for which surgery may be indicated. Serous carcinomas involving the peritoneum are now known to originate from tubal epithelium. They are of two distinct types, high grade and low grade, which are now recognized as different neoplasms with distinctive features, oncogenesis and behavior. Pseudomyxoma peritonei (PMP) is an unusual condition that usually arises from an appendiceal mucinous neoplasm. Recent consensus in the classification and nomenclature of these lesions is discussed, including the distinction between low grade and high grade appendiceal mucinous neoplasms (HAMN), and the diagnostic criteria for appendiceal adenocarcinoma. PMP is divided into four prognostic groups: acellular mucin, low grade mucinous carcinoma peritonei, high grade mucinous carcinoma peritonei, and high grade mucinous carcinoma peritonei with signet ring cells. The pseudomyxoma microbiome is a promising area for clinical intervention but has been the subject of little research activity. Goblet cell adenocarcinoma (previously known as 'goblet cell carcinoid') is a distinctive type of appendiceal adenocarcinoma. Its behavior correlates with histologic features, but no general consensus for classification has been reached., Competing Interests: Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jgo-2020-01). The focused issue was sponsored by the Peritoneal Surface Oncology Group International (PSOGI). The author has no other conflicts of interest to declare., (2021 Journal of Gastrointestinal Oncology. All rights reserved.)

High-throughput "-omics" analysis may provide a broader and deeper understanding of cancer biology to define prognostic and predictive biomarkers and identify novel therapy targets. In this review we provide an overview of studies where the peritoneal tumor component of peritoneal metastases from colorectal cancer (PM-CRC) and pseudomyxoma peritonei (PMP) were analyzed. Most of the available data was derived from DNA mutation analysis, but a brief review of findings from transcriptomic and protein expression analysis was also performed. Studies reporting genomic analysis of peritoneal tumor samples from 1,779 PM-CRC and 623 PMP cases were identified. The most frequently mutated genes in PM-CRC were KRAS , APC , SMAD4 , BRAF , and PIK3CA , while in PMP KRAS , GNAS , FAT4 , TGFBR1 , TP53 and SMAD3/4 mutations were most commonly identified. Analyses were performed by single-gene analyses and to some extent targeted next-generation sequencing, and a very limited amount of broad explorative data exists. The investigated cohorts were typically small and heterogeneous with respect to the methods used and to the reporting of clinical data. This was even more apparent regarding transcriptomic and protein data, as the low number of cases examined and quality of clinical data would not support firm conclusions. Even for the most frequently mutated genes, the results varied greatly; for instance, KRAS mutations were reported at frequencies between 20-57% in PM-CRC and 38-100% in PMP. Such variation could be caused by random effects in small cohorts, heterogeneity in patient selection, or sensitivity of applied technology. Although a large number of samples have been subjected to analysis, cross-study comparisons are difficult to perform, and combined with small cohorts and varying quality and detail of clinical information, the observed variation precludes useful interpretation in a clinical context. Although omics data in theory could answer questions to aid management decisions in PM-CRC and PMP, the existing data does not presently support clinical implementation. With the necessary technologies being generally available, the main challenge will be to obtain sufficiently large, representative cohorts with adequate clinical data and standardized reporting of results. Importantly, studies where the focus is specifically on peritoneal disease are needed, where the study designs are aligned with clearly defined research questions to allow robust conclusions. Such studies are highly warranted if patients with PM-CRC and PMP are to derive benefit from recent advances in precision cancer medicine., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jgo-20-136). The focused issue was sponsored by the Peritoneal Surface Oncology Group International (PSOGI). The authors have no other conflicts of interest to declare., (2021 Journal of Gastrointestinal Oncology. All rights reserved.)

Until recently, many classifications existed for the terminology and histopathologic classification of appendiceal mucinous neoplasms, mucinous appendiceal adenocarcinomas, and pseudomyxoma peritonei (PMP). A major accomplishment was achieved by consensus-based histopathologic classifications on behalf of the Peritoneal Surface Oncology Group International regarding mucinous appendiceal tumours and PMP. As different classifications were used over the years and also owing to the rare nature of these tumors, many clinicians are not familiar with the terminology and the impact on patient management. Hence, an overview concerning mucinous appendiceal neoplasms, mucinous appendiceal adenocarcinomas, and PMP is provided to serve as an introduction into the basic morphology of these tumors with tentative recommendations for management., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Introduction Pseudomyxoma peritonei (PMP) is a poorly understood uncommon condition with an estimated incidence of one to two per million (worldwide) per year. It is characterized by the peritoneal deposition of mucinous implants, diffusely involving the peritoneal surfaces, most commonly of the appendix, and occasionally from the ovary, coupled by mucinous ascites. PMP associated with primary ovarian mucinous tumor was very rare. Objectives to present a very rare case Method patient with large ovarian mass with ascites was operated to our institution which was diagnosed as borderline mucinous ovarian tumor with pseudomyxoma peritonei, case was reviewed and being a rare case it was prepare to present as rare case Result pseudomyxoma peritonei of ovarian origin is very rare and diagnosis is always a dilemma Conclusion Pseudomyxoma peritonei of ovarian origin is very rare its diagnosis usually based on clinical and immunohistochemistry finding [ABSTRACT FROM AUTHOR]

Background : The term pseudomyxoma peritonei (PMP) was first described in 1884 and there has been much debate since then over the term. A recent consensus of world experts agreed that PMP should be thought of as a clinical entity characterised by the presence of mucinous ascites, omental cake, peritoneal implants and possibly ovarian involvement. It generally originates from mucinous appendiceal tumours. Content : This review details the clinical presentation of this unusual condition, presents the new classification system and how this relates to outcome. The pathophysiology of this disease is also explored with a special reference to the relationship of the disease to tumour markers. Summary : A classification system has been agreed upon by the leading experts in PMP which is now divided into low and high grade mucinous carcinomatosis peritonei. This distinction correlates with clinical outcome as does the presence of raised tumour markers preoperatively. Outlook : Research needs to be focused on understanding the factors associated with poor prognosis through well designed multi-centred prospective studies. This will allow us to identify patients with bad tumour biology so that targeted treatment based on likely prognosis may then become a reality.

Background: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have shown variability in survival outcomes when used to treat peritoneal surface disease (PSD) from appendiceal and colorectal cancers. The primary goal of this study was to examine outcomes for high-grade appendiceal (HGA) and high-grade colonic primaries after CRS-HIPEC to determine if a significant difference exists between the two groups., Methods: A retrospective analysis of patients with peritoneal dissemination from appendiceal and colonic primaries were identified in a prospectively maintained database of 1,223 CRS-HIPEC procedures performed between 1991 and 2015. Patient demographics, performance status resection status, tumor grade, nodal status, morbidity, mortality, and survival were reviewed with biopsy-proven PSD being classified according to primary site. Univariate and multivariate analyses were performed, and outcomes compared., Results: The study identified 171 CRS-HIPEC procedures for 165 patients: 110 (66.7%) for HGA and 55 (33.3%) for high-grade colonic lesions. Observed median disease-free survival (DFS) and overall survival (OS) for both groups were the same at14.4 and 18 months, respectively. Median survival according to resection status for R0/R1, R2a, and R2b/c were 36, 15.6, and 8.4 months (P<0.0001). Median OS for those who received preoperative chemotherapy versus those who did not were 14.4 and 20.4 months, respectively (P=0.01). For those who received preoperative chemotherapy, no difference was apparent in the DFS interval (P=0.34). Multivariate predictors of OS included resection status (P<0.0001) and lymph node involvement (P=0.0005)., Conclusions: Preoperative chemotherapy offered no clear DFS or OS benefit, for HGA or high-grade colon cancer patients. Complete cytoreduction offered the greatest survival benefit to both groups with a correlating drop in survival to resection status. Outcomes for high grade appendiceal cancer are remarkably similar to colon cancer.

Introduction: Pseudomyxoma peritonei (PMP) is characteristically divided into two histopathological subtypes; disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). The latter is associated with a worse prognosis. However, even within the DPAM group, there is a considerable variation in outcome. In this study we investigate the role of baseline serum tumor markers CA 19-9, CEA and CA-125 in further stratifying survival., Methods: Over 16 years, 218 patients with PMP were treated with cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC) at our institution. A CA-125 level of >35 U/L, CA 19-9 of >40 U/mL and CEA of >3 ng/mL were considered positive or elevated outside the laboratory reference range. The impact of clinicopathologic and treatment-related variables on overall survival (OS) was analyzed with the Kaplan Meier method. Survival curves were compared using the log-rank test. Variables deemed significant by univariate analyses were entered into multivariate analysis using the Cox proportional hazards model., Results: Within the DPAM group, the 5-year survival of patients who were CA 19-9 positive versus those with normal values were 58% and 90% respectively (P<0.001). Other variables found to negatively impact on OS in univariate analyses were completeness of cytoreduction (CC) score 2/3 (P<0.001), peritoneal cancer index (PCI) >25 (P<0.001) and male gender (P=0.017). In the Cox regression model, only CA 19-9 positivity was found to be an independent prognostic factor for OS (P=0.034). In addition to marker positivity, the absolute level of CA 19-9 was also prognostically significant. In patients with CA 19-9>1,000 U/mL, the 5-year survival was 23%, in contrast to 90% in patients with CA 19-9<100 U/mL (P<0.001). In the PMCA cohort, only CC-score was found to be associated with OS (P<0.001)., Conclusions: Our study provides relevant prognostic information for the DPAM subtype in staging and prioritizing surgery; as even in apparently indolent disease, some patients have poorer survival. CA 19-9 elevation may also be useful in identifying patients who would potentially benefit from adjuvant therapy and/or closer post-operative surveillance. The potential role of CA 19-9 in mediating tumor cell adhesion and disease progression in PMP should be further investigated to deepen our understanding of the disease's inherent biological behavior. If a true relationship exists, CA 19-9 may be a conceivable target for immunotherapy.