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Introduction & Objectives: Treatment of PMP consists of appendectomy, cytoreductive surgery (CRS) and HIPEC. Right-sided hemicolectomy is necessary only when PMP is high grade, given the lymphatic invasion risk. To date, no single preoperative factor was identified as predictive of PMP grade., Materials & Methods: Preoperative factors of a prospective cohort study on PMP were retrospectively analyzed, in order to identify situations linked with high or low grade appendiceal PMP. The main outcome was PMP grade on definitive histology after CRS., Results: n = 105. In univariate analysis, the grade of the appendiceal tumor, systematically reviewed in an expert center, showed an OR of 25.00 (95 % CI: 3.30-189.27; p = 0.001) and an NPV of 93.75 [85.36, 100]. Peritoneal biopsy demonstrated an OR of 19.80 (95 % CI: 2.30-170.71; p = 0.002) and a PPV of 90 [71.41, 100]. In multivariate analysis, these two factors remained significantly associated with PMP grade., Conclusion: Whenever appendiceal tumor is low grade on preoperative histology, the colon has to be spared unless completeness of CRS is compromised, which is a high-grade feature in fact. In case of high grade appendiceal tumor and/or peritoneal biopsy, right-sided hemicolectomy is warranted. If no histology is available preoperatively, adapt to intraoperative lesions as no preoperative factors seem to be predictive., Competing Interests: Declaration of competing interest Authors did not report any disclosure for the study., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background and Aim: Two-stage cytoreductive surgery (CRS) has been proposed as an alternative to one-stage surgery in patients who have 'extensive' pseudomyxoma peritonei (PMP) and/or are unfit for very extensive surgery, to reduce morbidity. We review current evidence on two-stage CRS focusing on patient selection, interval between procedures, extent of surgery, use of HIPEC, perioperative and oncological outcomes., Methods: This is a narrative review. A literature search on PubMed and Embase was performed using keywords- 'Two-stage cytoreductive surgery', 'pseudomyxoma peritonei', 'high-volume PMP', 'huge PMP', 'cytoreductive surgery', 'HIPEC', 'staged surgery' and 'extensive pseudomyxoma peritonei'., Results: Five studies reported outcomes in a total of 114 patients. The indications for two-stage CRS were: in two studies, patients undergoing an incomplete cytoreduction due to undue surgical risk were reevaluated for a second surgery during routine surveillance; severe comorbidities in one; extensive disease with PCI>28 in another and in one, only HIPEC was performed as a second procedure due to intraoperative hemodynamic instability (the two-stage procedure was performed in interest of patient's safety). Major morbidity ranged from 0 to 37.5 % (first-stage) and 25%-38.9 % (second-stage). Short term follow-up demonstrated equivalent short-term oncological outcomes compared to historical data. Long term follow-up and quality-of-life data were not available., Conclusions: The published studies showed different interpretations and applications of the two-stage CRS concept. The reported morbidity was similar to that after single-stage CRS for extensive PMP. Though short-term survival outcomes are acceptable, long-term follow-up is needed. Planned two-stage CRS should currently be reserved for highly selected clinical situations., Competing Interests: Declaration of competing interest The authors have no disclosures. The authors have no conflicts of interest., (Copyright © 2024 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Introduction: Low-grade appendiceal mucinous neoplasms (LAMNs) are classified as non-perforated (pTis, pT3) or perforated (pT4), and considered precursors of pseudomyxoma peritonei (PMP). This study aims to quantify the risk of developing PMP from pTis and pT3 LAMNs., Materials and Methods: Retrospective analysis of a prospectively collected database identified LAMN patients referred to a specialist centre from 2004 to 2019. pT4 LAMNs and other appendix tumours were excluded. All patients had specialist review of their pathology, operation note, and a CT scan (at least 6 weeks post-operatively). Surveillance CTs were then performed at 6, 12, 24, 36, 48, & 60 months, with tumour markers (CEA, CA19-9, CA125)., Results: 193 pT3/pTis LAMN patients were included (pTis = 153, pT3 = 40). Median follow-up = 6.45 (3.91-22.13) years, M:F ratio = 1:1.57, and median age = 57 (23-83) years. Initial surgery included: appendicectomy (67 %), appendicectomy + visceral resection (6 %), and right hemicolectomy (27 %). R1 resections were identified in 5/193 patients (2.5 %). 3 R 1 patients underwent re-operation (2 caecal pole excision and 1 ileocecectomy), none of which had residual tumour. 8/193 patients (4 %) were lost to follow up. None of the remaining 185 developed PMP., Conclusion: This is the largest reported series of pTis/pT3 LAMNs with standardised follow-up in the literature. LAMNs correctly classified as pT3/pTis (after careful specialist review of pathology, operation note, and a baseline post-operative CT) have negligible risk of developing PMP and should have low intensity surveillance. If completely excised, further surgery is not indicated. R1 resections should be considered on an individual basis at a specialist centre., Competing Interests: Declaration of competing interest We the authors have no competing interests to declare regarding this submitted manuscript., (Copyright © 2024 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Gastropleural fistulas are rare complications with significant mortality and morbidity. There are limited reports on the successful management of gastropleural fistulas with advanced endoscopic procedures. The following case of a 75-year-old woman with a history of recurrent pseudomyxoma peritonei secondary to ruptured low-grade appendiceal mucinous neoplasm status post cytoreductive surgery highlights the successful treatment of a gastropleural fistula with endoscopic suturing., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Pseudomyxoma peritonei (PMP) is a rare neoplastic condition characterised by gelatinous ascites, which generally arise from mucin-producing appendiceal tumours. Presentation is variable but requires prompt recognition to ensure appropriate specialist management due to risk of malignancy.A male in his 40s presented with a 1-day history of sudden onset, non-migratory abdominal pain, worse in the right iliac fossa. He had no significant medical history nor known drug allergies. Examination revealed right iliac fossa peritonism and blood tests revealed raised inflammatory markers. CT scan showed a right-sided abdominal collection. Intraoperatively, a diagnostic laparoscopy was performed, which revealed extensive mucin in the abdominal cavity. This was washed out and a laparoscopic appendectomy was performed; histopathology confirmed PMP from the ruptured appendix., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

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., (© 2024. The Author(s).)

A 46-year-old female presented persistent right lower abdominal pain for 4 days. Computed tomography revealed an enlarged appendix with a surrounding low-attenuation mass. The patient was diagnosed with appendiceal abscess-forming appendicitis and initially treated with antibiotics. However, owing to the manifestation of nausea as a side effect, laparoscopic appendectomy was performed 3 days after the initial consultation. Intraoperative examination revealed mucinous material on the surface of the appendix and within the abdominal cavity, leading to the decision to perform an appendectomy with partial cecum resection and excision of the omentum with mucinous deposits. Pathological examination confirmed the diagnosis of a perforating low-grade appendiceal mucinous neoplasm and pseudomyxoma peritonei. The patient was subsequently referred to a specialized center for ongoing management, and at 9 months postoperatively, surveillance is being conducted. Low-grade appendiceal mucinous neoplasms can progress to pseudomyxoma peritonei through perforation; however, an optimal treatment approach has not yet been established. In particular, patients in advanced stages of the disease often require challenging management decisions. This case is reported along with a review of the literature to provide further guidance.

Background: Low-grade appendiceal mucinous neoplasms (LAMNs) are benign non-invasive epithelial proliferations of the appendix. These usually present clinically as mucoceles and these rarely exceed 2 cm in diameter. Lesions confined to the lumen are labelled as LAMN; however those in which mucin spreads outside the peritoneum are labeled as pseudomyxoma peritonei (PMP)., Aims and Objective: A retrospective study was conducted over a period of three years and all cases of appendectomies were studied. Twelve cases of LAMN were identified, which is a diagnostic dilemma for the pathologists and clinicians., Results: LAMN was identified based on the histopathological features. Out of the 12 cases, 9 were classified as LAMN and 3 as appendiceal neoplasm with PMP. There was villous or flat proliferation of epithelial lining, loss lymphoid aggregates, and dissecting mucin within muscularis., Conclusion: LAMNs are rare neoplasms of the appendix, with clinical presentation similar to acute appendicitis. Mucinous collections within the appendiceal wall should be extensively searched for mucosal changes and, if found, should prompt a careful search for pushing invasion of LAMNs. A thorough and vigilant gross examination can be of great help. Appendicectomy is the treatment of benign and grossly intact mucinous neoplasm., (Copyright © 2023 Copyright: © 2023 Journal of Cancer Research and Therapeutics.)

Introduction: Our study's objective was to provide the method for, and preliminary findings from, robot-assisted cytoreductive surgery (r-CRS) combined with upper-abdominal peritonectomy in pseudomyxoma peritonei (PMP) with limited peritoneal surface malignancy (PSM)., Materials and Methods: We conducted a retrospective pilot study on consecutive patients with PSM secondary to pseudomyxoma peritonei with a peritoneal cancer index (PCI) of under 10 who were indicated for r-CRS combined with upper-abdominal peritectomy. Perioperative and 30-day major morbidity and mortality characteristics were analyzed and compared with cases in which laparoscopic CRS (l-CRS) was performed under the same conditions., Results: Six patients underwent r-CRS combined with an upper-abdominal partial peritonectomy. Their mean PCI was 4.83. Complete cytoreduction was achieved in all patients. The mean duration of the operation was 156.8 minutes. There was no major complication and no mortality. The mean length of hospital stay after surgery was 6.33 days. r-CRS resulted in less blood loss, a lower C-reactive protein level, and a shorter length of hospital stay that were significantly different compared with those of l-CRS., Conclusions: This is the initial technical report of a robotic approach for CRS combined with upper-abdominal peritonectomy. r-CRS with a combined upper-abdominal peritonectomy was shown to be safe and feasible for PMP with limited PSM., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Backgrounds: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have improved survival for selected cases of peritoneal surface malignancy. In 2008, a CRS/HIPEC service was first established in Aotearoa New Zealand (AoNZ) at Waikato and Braemar Hospitals in the Waikato region., Methods: This is a retrospective review of a prospectively maintained database of all patients undergoing CRS/HIPEC from 1 January 2008 to 1 November 2020 at Waikato and Braemar Hospitals. We analysed long-term survival and predictors of survival for each tumour type., Results: 240 procedures were performed for 221 patients, including 22 re-do procedures. Cases had a median peritoneal cancer index of 16. Complete cytoreduction (CC0-1) was achieved in 196 cases (81.7%). All complete cytoreduction cases received HIPEC. There were 152 pseudomyxoma peritonei (PMP), 39 colorectal cancers (CRC), 29 appendiceal cancers, eight ovarian cancers, six peritoneal mesotheliomas, and six other cancers. The 5-year overall survival (OS) for PMP with acellular mucin, low-grade mucinous carcinoma peritonei, and high-grade mucinous carcinoma peritonei with or without signet cells were 91.6%, 80.5%, and 72.2%, respectively. 2- and 5-year OS in CRC were 56.7% and 40.4%. The achievement of complete cytoreduction improved the 5-year OS to 87.9% across all PMP and 45.1% in colorectal cancer. Incomplete cytoreduction predicted worse survival in appendiceal PMP. In colorectal cancer, worse survival was predicted in those who had incomplete cytoreduction, liver metastasis, and presentation with obstruction and perforation., Conclusion: Favourable long-term outcomes following CRS/HIPEC for peritoneal surface malignancy have been achieved in AoNZ through the Waikato peritonectomy service., (© 2023 Royal Australasian College of Surgeons.)

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., Competing Interests: Conflict of interest: None declared, (Copyright © The Author(s).)

Pseudomyxoma peritonei (PMP) of pancreatic origin arising from an intraductal papillary mucinous neoplasm (IPMN) is rare. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) has been established as the optimal treatment for PMP. However, the benefits and safety of CRS with HIPEC for treating PMP of pancreatic origin remain unclear. Herein, we describe a case of PMP of pancreatic origin that was treated with CRS and HIPEC without postoperative complications. A 75-year-old woman was referred to our department. Computed tomography (CT) revealed a multilocular cystic tumor in the pancreatic tail, notable mucinous ascites in the abdominal cavity, and scalloping of the liver and spleen. CT did not reveal the appendix, and the ovaries were normal in size. The patient was diagnosed with PMP of pancreatic origin, and CRS and HIPEC were performed. Intraoperatively, the pancreatic tumor was perforated, and there was a large amount of mucinous ascites. We performed distal pancreatectomy in addition to CRS and HIPEC, with no intraoperative complications. The postoperative course was uneventful, and the patient survived after 6 months without recurrence. CRS with HIPEC may be a feasible treatment option for PMP of pancreatic origin., (© 2023. Japanese Society of Gastroenterology.)

Background: To explore the application value of hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with incomplete cytoreduction for appendiceal pseudomyxoma peritonei (PMP)., Methods: We retrospectively analyzed the clinical data of 526 patients with incomplete cytoreduction for appendiceal PMP to discover its prognostic factors, and the therapeutic value of HIPEC., Results: The 5-year and 10-year overall survival rates of patients after cytoreductive surgery (CRS) treated with HIPEC were significantly higher than those without HIPEC (5y-OS: 58% vs. 48%, 10y-OS: 37% vs. 16%, P = 0.032). The median progression-free survival (PFS) following CRS was 20 months, with a 20% 3-year PFS. The median PFS following CRS + HIPEC was 33 months, with a 60% 3-year PFS (P = 0.000). Univariate analysis indicated that HIPEC, gender, completeness of cytoreduction (CCR) and pathological grade had statistical difference. Multivariate analysis showed that CRS without HIPEC and high pathological grade were independent risk factors for poor prognosis and rapid tumor progression., Conclusions: HIPEC may prolong the survival in patients with incomplete cytoreduction for low-grade appendiceal PMP. High pathological grade indicates poor survival and rapid tumor progression., (© 2024. The Author(s).)

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.

Peritoneal cancer index (PCI) is the surgical variable most commonly used to quantify the extent of peritoneal metastases for pseudomyxoma peritonei (PMP) patients. The present study aimed to investigate the agreement between CT predicted and surgical PCI by the Bland-Altman method for PMP of appendiceal origin. A total of 167 PMP patients of appendiceal origin were included between 2016 and 2021. Bland-Altman analysis was performed for both total PCI and selected PCI (regions 2 + 9-12). After the Bland-Altman plot was drawn, the mean bias and its 95% limit of agreements (LoAs) was quantified. Besides, the correlation coefficients between CT-PCI and surgical PCI were also been calculated. The Bland-Altman plot showed the mean bias ± SD between total CT-PCI and surgical PCI as 0.431 ± 3.005, with the LoAs from - 5.459 to 6.321. There were nine points of difference in total PCI exceeded the 95% LoAs, with the rate of 5.39% (9/167). As for selected CT-PCI, Bland-Altman plot showed the mean bias ± SD between selected CT-PCI and surgical PCI as - 0.287 ± 1.955, with the LoAs from - 4.118 to 3.544. There were ten points of difference in selected PCI exceeded the 95% LoAs, with the rate of 5.99% (10/167). The Spearman's rank correlation coefficient between total CT-PCI and surgical PCI was 0.911, P < 0.001, as for selected CT-PCI and surgical PCI, the coefficient was 0.909, P < 0.001. Although there was a strong correlation for both total and selected CT-PCI with surgical PCI, however, the agreement is still not good in Bland-Altman analysis, which suggested that CT-PCI cannot predict surgical PCI accurately even in professional PMP treatment centers. In brief explanation, CT makes it difficult to distinguish the borderline between tumor tissue and mucus and to detect tumor lesions in the small intestine regions, which caused overestimation or underestimation by CT-PCI. In the future, a multiple linear regression model based on CT-PCI might accurately predict surgical PCI preoperatively., (© 2023. The Author(s).)

Pseudomyxoma peritonei(PMP)is a rare condition caused by intraductal papillary mucinous neoplasm(IPMN). At our institution, 3 cases, along with literature review, of PMP caused by IPMN were treated with cytoreductive surgery. In case 1, a 70-year-old man was pathologically diagnosed with low-grade PMP with intraductal papillary mucinous carcinoma. Recurrence was discovered 68 months after surgery, and the patient died after 78 months. In case 2, a 69-year-old man was pathologically diagnosed with high-grade PMP with signet-ring cell carcinoma caused by intraductal papillary mucinous carcinoma. The patient died 8 months post-surgery. In case 3, a 77-year-old woman was pathologically diagnosed with low- grade(partially high-grade)PMP with intraductal papillary mucinous adenoma. There was a recurrence 14 months post- surgery. The patient is still alive because of systemic chemotherapy 32 months after surgery.

Patients with low-grade appendiceal mucinous carcinomas (LAMNs) treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have a favorable prognosis. However, a subgroup of patients presents a clinically aggressive course with disease progression despite receiving treatment. The purpose of this study is to report the experience of clinically aggressive LAMN patients treated by the same team, and to present a review of the literature. The cases of four patients with clinically aggressive LAMNs were reviewed. Clinical and histopathological characteristics were re-examined. Recurrences and the time of recurrence, as well as the survival time, were recorded. These patients were four men with clinically aggressive LAMNs treated with CRS plus HIPEC. One of them underwent CC-0 surgery, two underwent CC-1 surgery, and one underwent CC-3 surgery. All patients received systemic chemotherapy after surgery. Recurrence was recorded in three of the patients within 4-23 months after the initial treatment. Two of the patients underwent secondary CRS. Three patients died of disease recurrence within 13-23 months, and one is alive with a disease relapse at 49 months after his initial surgery. LAMNs were identified in both the initial specimens and the specimens obtained during reoperation. The prognosis of LAMN patients treated with CRS plus HIPEC is favorable. A small number of patients present a clinically aggressive course that is unresponsive to any treatment. Molecular and genetic studies are required to identify this group of LAMN patients who have an unfavorable prognosis.

Background: Pseudomyxoma peritonei syndrome (PMP) is an orphan disease. Surgery is the fundament of treatment., Method: Short review summarizing the state of the art treatment., Results: Cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) form the foundations of treatment for PMP. The peritoneal cancer index should be preoperatively determined based on imaging and/or laparoscopy, intraoperatively validated and both should be documented. An extraperitoneal surgical preparation technique leads to effective en bloc resection of the peritoneum and the affected abdominal area. The HIPEC technique should be performed with mitomycin C for 60-90 min. Complete CRS (CC = 0, CC = 1) and the histological subtype are relevant for the prognosis. Structured educational programs and mentoring can optimize the learning curve. The aftercare should be performed at the surgical center. After follow-up imaging at 3 months after CRS, in the first 2 years a control should be carried out every 6 months. Thereafter, the intervals can be extended to 1 year., Conclusion: Standardized surgical treatment and HIPEC, optimized specific surgical training and structured follow-up at the center lead to an excellent long-term prognosis for patients with PMP., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: The gold standard in the treatment of mucinous intra-abdominal neoplasms is cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC). Despite complete cytoreduction up to 45% of patients develop recurrences., Method: A search and analysis of the current literature were carried out., Results: There is still controversy regarding the best treatment strategy for patients with recurrent pseudomyxoma peritonei (PMP) after CRS and HIPEC. The clinical management of these patients depends on many factors, such as the site and volume of recurrence, histological subtype and symptoms. Treatment options range from repeated surgery with curative intent with or without HIPEC to watch and wait strategies. In selected patients redo surgery is feasible and safe with low morbidity and mortality. Iterative complete CRS can result in a median 5‑year overall survival of more than 80%. Debulking surgery leads to a prolonged survival and to symptom control fora period with of nearly 2 years., Conclusion: Repeated complete cytoreduction of recurrent PMP can result in long-term survival. Tumor debulking surgery may be particularly beneficial for symptomatic patients., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Competing Interests: Competing interests: None declared.

Aim: To evaluate percutaneous ultrasound-guided day-case mucin aspiration in advanced pseudomyxoma peritonei (PMP) using a wide-bore drain with regards to its safety and efficacy., Materials and Methods: All patients who underwent percutaneous mucin aspiration for PMP between 2019-2021 at a single national peritoneal tumour service were included in this study. Under local anaesthesia, a suction-enabled 28-32 F catheter was used for drainage following wire-guided track dilatation. The volume drained and difference in abdominal girth pre- and post-procedure were measured. Patients graded difficulty in breathing and abdominal discomfort pre- and post-procedure. Histology reports were reviewed., Results: Sixteen patients received 56 percutaneous mucin aspirations between 2019-2021. The aetiology was a low-grade appendiceal mucinous neoplasm (LAMN) in 50% of patients. The mean amount of mucin drained was 7,320 ± 3,000ml (range 300-13,500 ml). The mean reduction in abdominal girth post-procedure was 12.2 ± 5 cm (range 0-27 cm). Only grade 1 complications were observed., Conclusion: Percutaneous ultrasound-guided day-case aspiration of mucin for advanced and recurrent PMP using a wide-bore drain is a safe and effective procedure. It may be used in the palliative setting or as a bridge to surgery in the very symptomatic patient or if there is a reversible contraindication to surgery., (Copyright © 2023. Published by Elsevier Ltd.)

Objective: To report our experience with the combination of radical surgical excision and intestinal transplantation in patients with recurrent pseudomyxoma peritonei (PMP) not amenable to further cytoreductive surgery (CRS)., Background: CRS and heated intraoperative peritoneal chemotherapy are effective treatments for many patients with PMP. In patients with extensive small bowel involvement or nonresectable recurrence, disease progression results in small bowel obstruction, nutritional failure, and fistulation, with resulting abdominal wall failure., Methods: Between 2013 and 2022, patients with PMP who had a nutritional failure and were not suitable for further CRS underwent radical debulking and intestinal transplantation at our centre., Results: Fifteen patients underwent radical exenteration of affected intra-abdominal organs and transplantation adapted according to the individual case. Eight patients had isolated small bowel transplantation and 7 patients underwent modified multivisceral transplantation. In addition, in 7 patients with significant abdominal wall tumor involvement, a full-thickness vascularized abdominal wall transplant was performed. Two of the 15 patients died within 90 days due to surgically related complications. Actuarial 1-year and 5-year patient survivals were 79% and 55%, respectively. The majority of the patients had significant improvement in quality of life after transplantation. Progression/recurrence of disease was detected in 91% of patients followed up for more than 6 months., Conclusion: Intestinal/multivisceral transplantation enables a more radical approach to the management of PMP than can be achieved with conventional surgical methods and is suitable for patients for whom there is no conventional surgical option. This complex surgical intervention requires the combined skills of both peritoneal malignancy and transplant teams., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

We describe four cases of pseudomyxoma peritonei (PMP) that were diagnosed and treated at our hospital.Case 1: A 26-year-old woman with a large multicystic ovarian tumor and massive ascites was diagnosed with PMP originating from a borderline mucinous ovarian tumor. She underwent fertility-preserving staging laparotomy and was treated with three courses of intraperitoneal chemotherapy. There has been no recurrence in the 15 years since her first operation. Case 2: A 72-year-old woman with a giant ovarian tumor and massive ascites was diagnosed with PMP originating from low-grade appendiceal mucinous neoplasm (LAMN). After laparotomy, the patient was managed conservatively because she did not want aggressive treatment. She has remained asymptomatic with a small amount of ascites for 3 years. Case 3: A 82-year-old woman with ovarian tumors, massive ascites, and suspected PMP underwent emergency laparotomy due to appendiceal perforation and pan-peritonitis. She was diagnosed with PMP originating from LAMN. She has remained asymptomatic with a small amount of ascites for 2 years. Case 4: A 42-year-old woman with multicystic ovarian tumors and massive ascites underwent laparotomy. She was diagnosed with PMP originating from LAMN. Since multidisciplinary treatment was indicated and desired, the patient was referred to a specialized facility where cytoreductive surgery and hyperthermic intraperitoneal chemotherapy was performed. The patient has done well since the treatment.Although most cases of PMP originate from mucinous tumors of the appendix, female patients with PMP often present with ovarian tumors and are commonly referred to gynecology clinics. It is therefore important for gynecologists to be familiar with PMP and to be able to diagnose it accurately and select the most suitable management including multidisciplinary treatments.

Objectives: This study aimed to identify the diagnostic accuracy of combined ultrasonography (US) and computed tomography (CT) in evaluating the tumor burden of pseudomyxoma peritonei (PMP). Besides, we assessed the ability of this combination to predict the likelihood of complete resection., Methods: This retrospective study involved 504 patients diagnosed with PMP and scheduled for cytoreduction surgery. We compared tumor burden-quantified as peritoneal cancer index (PCI) by preoperative US and CT (US-CT-PCI)-with surgical findings. Next, we assessed the prognostic value of US-CT PCI and imaging features in determining the completeness of cytoreduction (CCR) score using multivariate analysis., Results: US-CT PCI demonstrated a high PCI evaluation accuracy under moderate tumor burden. Higher US-CT PCI could predict incomplete resection. In addition, we identified imaging features such as mesenteric involvement as an independent predictor of incomplete resection (hazard ratio (HR) = 2.006; p = 0.007)., Conclusions: US-CT PCI allowed us to predict the completeness of cytoreductive surgery in patients with PMP. Moreover, the combined US and CT imaging detected several features indicating incomplete cytoreduction., Key Points: • Ultrasonography (US) can act as a complementary diagnostic modality in peritoneal cancer index (PCI) evaluation by combining CT in the small bowel area and US in the abdominal area. • A modified peritoneal cancer index (US-CT PCI) helps preoperatively evaluate tumor burden with high accuracy and allows to predict incomplete resection. • US-CT PCI of 20 or above and the involvement of particular structures such as mesentery, independently indicate incomplete resection., (© 2022. The Author(s).)

Pseudomyxoma peritonei (PMP) is a rare disease associated with mucinous ascites. Pseudomyxoma peritonei has a low incidence and is difficult to diagnose. Pseudomyxoma peritonei usually presents with vague abdominal pain after significant progression. Computed tomography imaging is the most common modality for diagnosis; however, diagnosis as a result of surgical intervention in cases of acute abdomen has become increasingly common. We present a unique case of a 66-year-old man who was incidentally diagnosed with PMP after undergoing an emergent splenectomy for presumed blunt trauma. The patient presented to the emergency room with abdominal pain, shortness of breath, and diaphoresis. Computed tomography imaging revealed a splenic hematoma with suspicion of extravasation and a moderate amount of free intraperitoneal fluid consistent with blood. The patient was taken to the operating room emergently for an emergent splenectomy where splenic laceration was noted, as were multiple areas of nodularity in the omentum and cecum. Histologic evaluation of these lesions led to the diagnosis of PMP. After recovery from his initial splenectomy, the patient underwent exploratory laparotomy, cytoreductive surgery, cholecystectomy, removal of appendiceal mucocele, and hyperthermic intraperitoneal chemotherapy without complication. Final pathology was consistent with PMP and primary mucinous appendiceal adenocarcinoma. This case highlights an unusual presentation of PMP for a patient who was undergoing surgery for presumed splenic trauma. Surgeons must maintain a high index of suspicion and should perform histological evaluation when such unexpected findings are encountered., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To investigate the clinical value of laparoscopic cytoreductive surgery (CRS) in treating of appendiceal pseudomyxoma peritonei with limited disease and low tumor burden., Methods: The clinical data of patients with appendiceal pseudomyxoma peritonei treated by surgery with CRS at the Aerospace Center Hospital from January 2018 to December 2021 were retrospectively analyzed. The patients were divided into laparoscopic or open CRS groups according to the operation method. A propensity score-matched (PSM) analysis (1:1) was performed, the related clinical variables were compared between the two groups, and the effect on progression-free survival (PFS) was also analyzed., Results: One hundred and eight patients were included in this study. After PSM, 33 patients were selected from each group and the age and peritoneal cancer index were matched between the two groups. There were significant differences in operation time (P < 0.001), intraoperative bleeding (P < 0.001), intraoperative blood transfusion (P = 0.007), hospital stay (P < 0.001). The analysis of PFS showed that there was no significant difference between the two operation methods. After multivariate analysis, the pathologic subtype (P = 0.012) was identified as an independent prognostic factor for PFS., Conclusion: The curative effect of laparoscopic CRS is like that of open operation, which can significantly shorten the operation time and hospital stay and reduce intraoperative bleeding and blood transfusion event. The laparoscopic CRS is safe and feasible in strictly selected patients. The pathologic subtype is an independent factor affecting the prognosis for PFS., (Copyright © 2023 Asian Surgical Association and Taiwan Robotic Surgery Association. Published by Elsevier B.V. All rights reserved.)

Background: Pseudomyxoma peritonei (PMP) is a clinically malignant tumour syndrome mainly derived from mucin-producing appendiceal tumours. This study aimed to explore the effect of preoperative systemic chemotherapy (PSC) before cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) on the safety and postoperative survival in patients with appendiceal PMP., Methods: We performed a retrospective analysis including consecutive patients with PMP undergoing primary surgery between January, 2008 and December, 2019 in Aerospace Center Hospital. The clinical data and postoperative survival were compared between PSC group and non-PSC group., Results: Seven hundred and fifty patients were included in the study. Significant differences were found between PSC group and non-PSC group on clinicopathological data and perioperative outcomes and the independent risk factor of serious complications was blood loss >1000 mL (P = 0.026). Shorter median overall survival (OS) was found (42 months, 95% CI 31.9-52.1) in PSC group than that (67 months 95% CI 44.5-89.5) in non-PSC group. In the stratified study with PCI < 20, CC 0/1 and low-grade pathological subtype, the OS from non-PSC group was significantly better than that in PSC group (log rank P-values are <0.001, 0.006 and <0.001, respectively). Multivariate survival analysis showed that CC 0/1, HIPEC, PCI < 20 and low-grade pathological subtype were the independent prognostic factors for better OS., Conclusions: PSC does not increase the risk of major perioperative complications in patients with appendiceal PMP, but it also does not bring postoperative survival benefits to patients either., (© 2022 The Authors. ANZ Journal of Surgery published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Surgeons.)

Pseudomyxoma peritonei (PMP) is a rare condition that results from the dissemination of a mucinous primary tumor and the resultant accumulation of mucin-secreting tumor cells in the peritoneal cavity. PMP can arise from various types of cancers, including appendiceal, ovarian, and colorectal, though appendiceal neoplasms are by far the most common etiology. PMP is challenging to study due to its (1) rarity, (2) limited murine models, and (3) mucinous, acellular histology. The method presented here allows real-time visualization and interrogation of these tumor types using patient-derived ex vivo organotypic slices in a preparation where the tumor microenvironment (TME) remains intact. In this protocol, we first describe the preparation of tumor slices using a vibratome and subsequent long-term culture. Second, we describe confocal imaging of tumor slices and how to monitor functional readouts of viability, calcium imaging, and local proliferation. In short, slices are loaded with imaging dyes and are placed in an imaging chamber that can be mounted onto a confocal microscope. Time-lapse videos and confocal images are used to assess the initial viability and cellular functionality. This procedure also explores translational cellular movement, and paracrine signaling interactions in the TME. Lastly, we describe a dissociation protocol for tumor slices to be used for flow cytometry analysis. Quantitative flow cytometry analysis can be used for bench-to-bedside therapeutic testing to determine changes occurring within the immune landscape and epithelial cell content.

Background: Appendiceal mucinous neoplasms are routinely accompanied by peritoneal metastases at the time of diagnosis of the primary appendiceal tumor. In contrast, liver metastases and lymph node metastases are unusual., Methods: From an extensive database, patients with lymph node metastases identified at the time of primary appendiceal cancer resection were selected for special study. The clinical, treatment-related and histologic variables of this group of patients were statistically analyzed for their impact on overall survival., Results: From a prospectively maintained database of 685 patients with a complete cytoreduction of a mucinous appendiceal neoplasm with peritoneal dissemination, 39 patients (5.6%) had lymph node metastases at the time of primary diagnosis. The median follow-up was 5.0 years and overall median survival was 6.0 years. Histologically, 6 of these patients (15.4%) had an appendiceal mucinous neoplasm - Intermediate type (MACA-Int). In 5 patients, the involved lymph nodes were not within the ileocolic lymph node group. The 7 patients (17.9%) who had a complete or near complete response to neoadjuvant chemotherapy prior to definite cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) showed prolonged survival (HR 4.8 (1.1, 20.5) p = 0.0323). A prior right colon resection required repeat resection in 87% of patients., Conclusion: Long-term survival is unusual but occasionally seen in this group of patients. Response to neoadjuvant chemotherapy is an important determinant of a favorable outcome., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest associated with the manuscript entitled “Lymph node positive pseudomyxoma peritonei”., (Copyright © 2022 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

A 49-year-old male patient, who presented with abdominal pain, was suspected of having acute appendicitis. Abdominal computed tomography revealed a swollen appendix, accompanied by a 40 mm low-density mass located behind the appendix. He was diagnosed with an appendiceal mucinous neoplasm, and laparoscopic ileocecal resection was performed. A soft tumor was found proximal to the swollen appendix and was adhered tightly to the iliopsoas muscle. The tumor cells were exfoliated carefully, and the tumor was excised en bloc without any injury. Histopathological examination revealed a low- grade appendiceal mucinous neoplasm(LAMN)accompanied by extra-appendiceal mucin extrusion due to the lack of epithelial lining. Because LAMN is potentially malignant, surgical excision was performed as first-line therapy. In the surgical management of LAMN, preventing intraoperative rupture is essential to avoid pseudomyxoma peritonei. To achieve this, a magnified laparoscopic surgery may be useful. Although no definitive guidelines describing the indications of lymph node dissection or the appropriate extent of resection exist, laparoscopic ileocecal resection may be used to manage cases of LAMN.

In 1998, the Peritoneal Surface Oncology Group International(PSOGI)proposed a novel treatment referred to as comprehensive treatment(COMPT). COMPT involves the complete removal of macroscopic tumors(cytoreductive surgery: CRS) and eradication of micrometastasis(MM)with neoadjuvant chemotherapy(NAC)plus intraoperative hyperthermic intraperitoneal chemotherapy(HIPEC). This article provides a rationale for curative COMPT. Additionally, based on our experience, the selection criteria for treatment will be clarified., Rationale: The residual cancer cell burden is lowest immediately following CRS, and intraoperative HIPEC plays a crucial role in the treatment of patients with peritoneal surface malignancy (PSM). COMPT will fail if the number of the MM remaining after CRS exceeds the limit of complete eradication by intraoperative HIPEC(threshold). However, if the residual number of MM is less than the threshold, patients will respond positively to treatment., Patients and Methods: To validate the direct effect of HIPEC, laparoscopic HIPEC(LHIPEC)was performed, and changes in the peritoneal cancer index(PCI)were then evaluated. Complete cytoreduction and HIPEC carried out based on the concept of COMPT was performed in 171 gastric cancer(GC)patients with PCI≤12, 183 colorectal cancer(CRC)with PCI≤21 and 460 pseudomyxoma peritonei(PMP)patients with PCI≤28. The postoperative survivals rates were then analyzed., Results: After 1 cycle of LHIPEC, PCIs in GC and PMP were significantly reduced by 1.85 and 2.7 1 month after LHIPEC. However, PCI of CRC increased. Positive cytology at LHIPEC became negative in 57.6%, 42.9% and 60.9% of patients with GC, CRC and PMP, respectively. Median survival time(MST)for GC and CRC was 21.2 and 71.5 months, respectively MST of PMP was not reached. MST of PMP was not reached. Ten-year survival rates were 12.6%, 21.7% and 81.6%, respectively. Grade 5 complications for each disease were 0.8%, 1.0% and 1.1%, respectively., Conclusions: Complete cytoreductive surgery combined with intraoperative HIPEC may improve the long-term survival of patients with PSM who have PCIs less than the threshold levels, by keeping the mortality rates after CRS plus intraoperative HIPEC within acceptable levels.

Appendiceal mucinous neoplasms (AMNs), characterized by expansile or "pushing" growth of neoplastic epithelium through the appendix wall, are sometimes accompanied by peritoneal involvement, the extent and grade of which largely determine clinical presentation and long-term outcomes. However, the prognosis of tumors entirely confined to the appendix is still debated and confusion remains regarding their biologic behavior and, consequently, their clinical management and even diagnostic nomenclature. We evaluated AMNs limited to the appendix from 337 patients (median age: 58 years, interquartile range (IQR): 47-67), 194 (57.6%) of whom were women and 143 (42.4%) men. The most common clinical indication for surgery was mass or mucocele, in 163 (48.4%) cases. Most cases (N = 322, 95.5%) comprised low-grade epithelium, but there were also 15 (4.5%) cases with high-grade dysplasia. Lymph nodes had been harvested in 102 (30.3%) cases with a median 6.5 lymph nodes (IQR: 2-14) per specimen for a total of 910 lymph nodes examined, all of which were negative for metastatic disease. Histologic slide review in 279 cases revealed 77 (27.6%) tumors extending to the mucosa, 101 (36.2%) to submucosa, 33 (11.8%) to muscularis propria, and 68 (24.4%) to subserosal tissues. In multivariate analysis, deeper tumor extension was associated with older age (p = 0.032; odds ratio (OR): 1.02, 95% confidence intervals (CI): 1.00-1.03), indication of mass/mucocele (p < 0.001; OR: 2.09, CI: 1.41-3.11), and wider appendiceal diameter, grossly (p < 0.001; OR: 1.61, CI: 1.28-2.02). Importantly, among 194 cases with at least 6 months of follow-up (median: 56.1 months, IQR: 24.4-98.5), including 9 high-grade, there was no disease recurrence/progression, peritoneal involvement (pseudomyxoma peritonei), or disease-specific mortality. These data reinforce the conclusion that AMNs confined to the appendix are characterized by benign biologic behavior and excellent clinical prognosis and accordingly suggest that revisions to their nomenclature and staging would be appropriate, including reverting to the diagnostic term mucinous adenoma in order to accurately describe a subset of them., (© 2022. The Author(s), under exclusive licence to United States & Canadian Academy of Pathology.)

Purpose: Accurate assessment of preoperative tumor burden contribute to formulate a scientific surgical plan for patients with pseudomyxoma peritonei (PMP). Present study aimed to assess whether the preoperative plasma D-Dimer level could reflect tumor burden for PMP patients., Methods: A total of 253 PMP patients were included between June 1, 2013 and March 1, 2022. According to the peritoneal cancer index (PCI), all participants were divided into extensive (PCI ≥ 28) and none-extensive (PCI < 28) subgroups. The D-Dimer and tumor markers were compared between the two subgroups. The correlation between the abovementioned biomarkers and PCI will be calculated, and further compared with each other. Two-sided P value less than 0.05 is considered statistically significant., Results: The level of D-Dimer (ng/ml) between extensive and none-extensive subgroup were 600 (328, 1268) vs. 339 (128, 598), Z = -5.425, p < 0.001. The Spearman correlation between D-Dimer, carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA 125), CA 19 - 9 and PCI were 0.487, 0.509, 0.469, and 0.499, respectively (all p < 0.001). The correlation coefficients were compared with each other according to Meng, Rosenthal and Rubin's method, however, there was no significant difference., Conclusion: Preoperative plasma D-Dimer could moderately reflect tumor burden for PMP. In the future, a multivariate prediction model will be developed to help surgeons to formulate a more precise surgical plan for the PMP patients., (© 2022. The Author(s).)

Background: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is the best effective treatment for pseudomyxoma peritonei (PMP). In the last years, the advances in histopathology have stratified PMP lesions in different degrees of aggressivity suggesting the possibility of a tailored treatment. In a subset of patients with small volume peritoneal disease, laparoscopic CRS and HIPEC is feasible. The aim of this study is to analyze the results of laparoscopic CRS + HIPEC in a monocentric series of patients under patient-related experience measures (PREMs)., Methods: All consecutive patients who underwent laparoscopic CRS-HIPEC with curative intent at Cancer Institute of Montpellier were retrieved from a prospectively maintained database and analyzed. Selection criteria for laparoscopic approach were low-grade PMP with pathological confirmation prior to CRS-HIPEC, age < 75 years, no extra-peritoneal disease, peritoneal cancer index (PCI) < 10, and a limited history of abdominal surgery. A PREMS interview was conducted before analysis with all the included patients. Outcomes of interest included postoperative morbidity, medium-term survival, and PREMs., Results: Fourteen patients were operated on for low-grade PMP with a laparoscopic approach at our institution. Conversions to laparotomy were necessary in three patients, and postoperative complications were observed in three patients (Clavien 3b in one patient). In-hospital postoperative median stay was 9.5 days. No death or recurrence was observed during the study period., Conclusions: Laparoscopic CRS-HIPEC for LAMN in presence of small peritoneal disease is feasible in terms of postoperative morbidity and mortality. According to our PREMs questionnaire, patients' expectations were satisfied., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: There is ongoing controversy concerning the indications and benefits of early postoperative intraperitoneal chemotherapy (EPIC) following cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy (HIPEC) in patients with pseudomyxoma peritonei. The main contra-indications preventing wide-spread use of EPIC are reports of an increased postoperative morbidity with no clear evidence of oncological benefit. This paper reports a single high volume institution experience with EPIC over a 25-year period., Methods: This is a retrospective analysis of a single institution prospective database of patients undergoing CRS and HIPEC for appendiceal neoplasms from March 1994 to December 2019. Sub group analysis of patients who received EPIC with 5FU 15mg/m2 is reported and compared with patients who did not receive EPIC., Results: Overall, 632/1564 (40%) received EPIC. Patients who received EPIC were younger (median age 55 (IQR 45-63) vs 59 (IQR 50-68)) with similar extent of disease to those who did not have EPIC. EPIC was more likely to be given after complete cytoreduction. The use of EPIC has reduced over the last 25 years from 78% of patients initially to 16% most recently. Length of stay in critical care and total hospital stay were longer in patients who received EPIC but surprisingly major morbidity (Clavien Dindo Grade >3) was lower (p = 0.001)., Conclusion: EPIC can be administered safely following CRS and HIPEC for PMP of appendix origin when used in carefully selected patients in a high-volume centre. Randomised trials are needed to establish impact on disease free and overall survival to optimize selection criteria., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

Introduction: The pathologic classification of pseudomyxoma peritonei is controversial. This study aimed to standardize the histopathological evaluation of pseudomyxoma peritonei and identify the clinicopathological factors associated with survival., Methods: A pathologic review was performed to systematize the pathology report and verify the relationship between clinical features and survival. Terminology was based on the World Health Organization and Peritoneal Surface Oncology Group International definitions. Preoperative serum levels of carcinoembryonic antigen, CA19-9, and CA-125 were evaluated to determine their association with overall survival (OS) and ability to predict CC0-1 cytoreduction., Results: Among 109 patients with carcinomas resulting from primary appendiceal neoplasms, 72 had pseudomyxoma peritonei of appendiceal origin and underwent debulking surgery. CC0-1 cytoreduction and CC2-3 cytoreduction were achieved in 61% and 39% of patients, respectively. Patients in the CC0-1 and CC2-3 groups had an OS of 122.80 and 32.92 mo, respectively. The histologic grade was associated with CC0-1 cytoreduction; however, it did not influence OS. Patients with CC0-1 cytoreduction, acellular mucin, and low-grade lesions had better disease-free survival. Higher preoperative CA19-9 levels were associated with poor OS. Normal carcinoembryonic antigen values were associated with 100% sensitivity for predicting CC0-1. CA19-9 levels of 625 U/mL were associated with a low possibility of predicting CC0-1., Conclusions: Histologic grades are associated with disease-free survival when CC0-1 cytoreduction is achieved. Normal preoperative CA19-9 levels were associated with a better OS. CC0-1 cytoreduction is the main determinant of longer survival., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The discovery of a low grade appendiceal mucinous neoplasm (LAMN) during appendectomy is a rare scenario. These neoplasms can progress to pseudomyxoma peritonei (PMP), however the incidence of progression is not well known., Methods: The records of all patients with a diagnosis of localized LAMN found during appendectomy were identified, and demographic, tumor, surveillance, and outcome variables were analyzed., Results: Progression to PMP occurred in 20% of patients in an average of 12.4 months after appendectomy with median follow-up of 18 months. Tumor variables such as margin positivity, appendiceal perforation, and presence of extra-appendiceal acellular mucin or mucinous epithelium on the serosal were not significantly associated with progression., Conclusions: During an average follow-up period of 18 months after surgery, progression to PMP occurred in a fifth of patients. It is difficult to predict which patients will progress, therefore cross-sectional imaging surveillance is recommended for all patients., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The objective of this systematic review is to provide efficacy and safety data in the application of Intra-Abdominal Hyperthermia Chemotherapy (HIPEC) and Cytoreductive Surgery (CRS) in patients with Peritoneal Pseudomyxoma (PMP) of origin in the cecal appendix. The databases Medline and Central Cochrane were consulted. Patients with PMP of origin in the cecal appendix, classified as low grade, high or indeterminate, submitted to HIPEC and CRS. The results were meta-analyzed using the Comprehensive Metanalysis software. Twenty-six studies were selected to support this review. For low-grade PMP outcome, 60-month risk of mortality, Disease-Free Survival (DFS), and adverse events was 28.8% (95% CI 25.9 to 32), 43% (95% CI 36.4 and 49.8), and 46.7% (95% CI 40.7 to 52.8); for high-grade PMP, 60-month risk of mortality, Disease-Free Survival (DFS) and adverse events was 55.9% (95% CI 51.9 to 59.6), 20.1% (95% CI 15.5 to 25.7) and 30% (95% CI 25.2 to 35.3); PMP indeterminate degree, 60-month risk of mortality, Disease-Free Survival (DFS) and adverse events was 32.6% (95% CI 30.5 to 34.7), 61.8% (95% CI 58.8 to 64.7) and 32.9% (95% CI 30.5 to 35.4). The authors conclude that the HIPEC technique and cytoreductive surgery can be applied to selected cases of patients with PMP of peritoneal origin with satisfactory results., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2022 HCFMUSP. Published by Elsevier España, S.L.U. All rights reserved.)