Pseudomyxoma peritonei: natural history and treatment

Successful treatment of pseudomyxoma peritonei (PMP) through cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC): A case report and literature review

INTRODUCTION AND IMPORTANCE

Pseudomyxoma peritonei (PMP) is characterized by the accumulation of mucinous fluid in the abdominal cavity, typically originating from mucin-producing tumors, most commonly arising in the appendix.

CASE PRESENTATION

A 63-year-old male patient presented to the hospital with complaints of abdominal pain, significant weight loss, a palpable mass in the right iliac fossa, and evidence of ascites. A diagnosis of PMP was proposed based on findings from a computed tomography (CT) scan, which was subsequently confirmed through histopathological examination of a biopsy. The patient underwent successful treatment with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS-HIPEC).

CLINICAL DISCUSSION

Diagnosing PMP presents challenges due to its rarity and the potential for extensive spread throughout the peritoneal cavity, necessitating a multidisciplinary approach for successful treatment.

CONCLUSION

Pseudomyxoma peritonei is a rare yet medically significant condition. Documenting a case of this ailment in Palestine has the potential to advance medical understanding, raise awareness, and improve patient care standards within the local healthcare system. By documenting this uncommon condition, healthcare practitioners in Palestine can gain valuable insights into its manifestations, diagnostic processes, and treatment modalities. This contribution not only enriches the global medical literature but also promotes collaboration in addressing the challenges associated with rare diseases.

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

BACKGROUND

Careful macroscopic assessment of surgical scars is needed to avoid routine scar resection during cytoreductive surgery (CRS) for peritoneal metastases (PM). This study aimed to analyze the correlation between macroscopically suspected and microscopically confirmed scar metastases (SMs), and to analyze the prognostic impact of not undergoing routine scar resection.

METHOD

All patients with previous surgery, treated with CRS and hyperthermic intraperitoneal chemotherapy, for colorectal PM or pseudomyxoma peritonei (PMP), at Uppsala University Hospital in 2013-2021, were included. Macroscopic SMs in surgical reports were compared with histopathological analyses.

RESULTS

In total, 227 patients were included. Among colorectal PM patients (n = 156), SM was macroscopically suspected in 41 (26%) patients, and 63 (40%) underwent scar resection. SM was confirmed in 19 (30%). Among patients with macroscopic suspicion, 45% had confirmed SM (positive predictive value, PPV). A total of 1 of 23 (4%) patients with no macroscopic suspicion had SM (negative predictive value, NPV = 96%). Among the PMP patients (n = 71), SM was macroscopically suspected in 13 (18%), and 28 (39%) underwent scar resection, of whom 12 (43%) had SM. The PPV was 77%. Occult SM was found in 1 of 14 (NPV = 93%). Not undergoing routine scar resection did not affect recurrence-free survival (RFS, p = 0.2) or overall survival (OS, p = 0.1) in colorectal PM patients or PMP patients (RFS p = 0.7, OS p = 0.7).

CONCLUSION

Occult SM is uncommon and scar resection does not affect RFS or OS. Therefore, macroscopically benign-appearing scars can be left without resection, though resection should be performed upon suspicion or uncertainty.

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

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

Appendiceal Mucinous Neoplasm: A Case of an Incidental Finding

Appendiceal mucinous neoplasms (AMNs) are uncommon gastrointestinal tumors characterized by mucus accumulation in the appendix. Patients may complain of acute appendicitis-like symptoms with other alarming features, but approximately half of the cases of AMNs are found incidentally on imaging. Early diagnosis and management of these neoplasms are important to prevent malignant progression and complications such as bowel obstruction and pseudomyxoma peritonei. We report a case of a 28-year-old female who initially presented with vomiting and acute left lower abdominal pain radiating to the left flank. Computed tomography (CT) revealed a 1.5 mm stone in the left ureteral vesicular junction and a 2.3 x 2.4 x 5.2 cm cystic tubular mass at the base of the cecum, suspicious of an appendiceal mucocele. An elective laparoscopic appendectomy was performed on this admission, which was converted to a right hemicolectomy due to the pathologic finding of a focally high-grade AMN on intraoperative frozen specimen pathology. This report aims to provide an example of a case of an incidental AMN and how it was diagnosed and managed surgically. AMNs are rare tumors that originate from the appendix and can pose diagnostic and therapeutic challenges due to their diverse clinical presentations and variable histopathological features. The majority of cases of AMNs are discovered in middle-aged individuals (40-50 years of age) after an appendectomy is performed and examined by pathology. This case report aims to describe a rare presentation of a 28-year-old female patient with an incidental finding of AMN on a CT scan of the abdomen while being worked up for suspected nephrolithiasis. We will provide a comprehensive overview of a unique presentation of AMN, highlighting its clinical manifestations, diagnostic approach, and management strategies. We present the case of a 28-year-old female patient who presented to the emergency department with complaints of acute left lower quadrant abdominal pain radiating to the left flank and vomiting. After an initial assessment and workup, which included lab investigations and imaging, a diagnosis of unilateral hydronephrosis due to a calculus of the ureterovesical junction was made. However, there was also suspicion of an appendiceal mucocele, as evidenced by a CT scan of the abdomen and pelvis. On admission day one, under the care and management of the urology team, she passed the stone with complete resolution of the presenting symptoms. On hospital day two, she underwent an elective laparoscopic appendectomy followed by a right hemicolectomy due to findings of high-grade mucinous neoplasm on the resected frozen specimen near the base of the appendix. AMN was an incidental finding based on CT imaging and macroscopic findings, which was later confirmed by histopathological assessment and report.

Progress in Biological Research and Treatment of Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PMP) is a rare disease characterized by extensive peritoneal implantation and mass secretion of mucus after primary mucinous tumors of the appendix or other organ ruptures. Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is currently the preferred treatment, with excellent efficacy and safety, and is associated with breakthrough progress in long-term disease control and prolonged survival. However, the high recurrence rate of PMP is the key challenge in its treatment, which limits the clinical application of multiple rounds of CRS-HIPEC and does not benefit from conventional systemic chemotherapy. Therefore, the development of alternative therapies for patients with refractory or relapsing PMP is critical. The literature related to PMP research progress and treatment was searched in the Web of Science, PubMed, and Google Scholar databases, and a literature review was conducted. The overview of the biological research, treatment status, potential therapeutic strategies, current research limitations, and future directions associated with PMP are presented, focuses on CRS-HIPEC therapy and alternative or combination therapy strategies, and emphasizes the clinical transformation prospects of potential therapeutic strategies such as mucolytic agents and targeted therapy. It provides a theoretical reference for the treatment of PMP and the main directions for future research.

Global trends in research of pseudomyxoma peritonei: a bibliometric and visualization analysis

Objective

Pseudomyxoma peritonei (PMP) was a complex disease that had attracted increasing attention. However, there had been no bibliometric analysis of this disease so far. This study aimed to explore the current situation and frontier trend of PMP through bibliometric and visualization analysis, and to indicate new directions for future research.

Methods

The original research articles and reviews related to the PMP research were downloaded from Web of Science Core Collection on September 11, 2023. CiteSpace (6.2.R4) and VOSviewer(1.6.18) were used to perform bibliometric analysis of the publications, and establish the knowledge map. The data collected was analyzed using the Online Analysis Platform of Bibliometric to evaluate the cooperation of countries in this field.

Results

We identified 1449 original articles and reviews on PMP published between 1998 and 2023. The number of publications on PMP increased continuously. The United States, the United Kingdom and China were the top contributors. The most productive organization was the MedStar Washington Hospital Center. Sugarbaker, Paul H. was the most prolific author and the most cited. Keyword analysis showed that "Pseudomyxoma peritonei", "cancer", "cytoreductive surgery", and "hyperthermic intraperitoneal chemotherapy" were the most common keywords. The earliest and latest used keywords were "mucinous tumors" and "impact", respectively. "classification", "cytoreductive surgery", "appendiceal" were the top 3 strongest citation bursts. The reference "Carr NJ, 2016, AM J SURG PATHOL" had the highest co-citations.

Conclusion

This bibliometric analysis showed an increasing trend in literature related to PMP. The research trends and hotspots identified in this study could guide the future research directions in this field, in order to promote the development of PMP.

A case of pseudomyxoma peritonei arising from a perforated intraductal papillary mucinous neoplasm that underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

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.

Optimal peritoneal cancer index cutoff point for predicting surgical resectability of pseudomyxoma peritonei in treatment-naive patients

BACKGROUND

The peritoneal cancer index (PCI) has been used to predict surgical outcomes for pseudomyxoma peritonei (PMP). The present study aimed to establish the optimal cutoff point for PCI to predict surgical resectability of PMP.

METHODS

A total of 366 PMP patients were included. The patients were divided into low-grade and high-grade groups. Based on the completeness of the cytoreduction (CC) score, both low-grade and high-grade PMP patients were further divided into complete cytoreductive surgery (CRS) and maximal tumor debulking (MTD) subgroups. The ability to predict surgical resectability of total and selected PCI (regions 2 + 9 to 12) was analyzed through receiver operating characteristic (ROC) curves.

RESULTS

Both total and selected PCI demonstrated excellent discriminative ability in predicting surgical resectability for low-grade PMP patients (n = 266), with the ROC-AUC of 0.940 (95% CI: 0.904-0.965) and 0.927 (95% CI: 0.889-0.955). The corresponding optimal cutoff point was 21 and 5, respectively. For high-grade PMP patients (n = 100), both total and selected PCI exhibited good performance in predicting surgical resectability, with the ROC-AUC of 0.894 (95% CI: 0.816-0.946) and 0.888 (95% CI: 0.810-0.943); correspondingly, the optimal cutoff point was 25 and 8, respectively. The discriminative ability between total and selected PCI in predicting surgical resectability did not show a statistical difference.

CONCLUSIONS

Both total and selected PCI exhibited good performance and similarity in predicting complete surgical resection for both low-grade and high-grade PMP patients. However, the selected PCI was simpler and time-saving in clinical practice. In the future, new imaging techniques or predictive models may be developed to better predict PCI preoperatively, which might assist in confirming whether complete surgical resection can be achieved.

Origin and survival outcomes of Pseudomyxoma peritonei-A retrospective study

BACKGROUND

Pseudomyxoma peritonei (PMP) is an unusual clinical condition typically presenting with widespread mucinous neoplastic lesions within the peritoneum resulting in gelatin material-rich ascites. It was first described by Werth in 1884. Ever since, its clinical presentation, definition, site of origin, and prognosis have been a subject of debate. However, many histopathologic, immunohistochemical, and genetic studies have attempted to locate the primary lesion in the appendix in both genders.

OBJECTIVES

To analyze the histological origin and survival outcomes of pseudomyxoma peritonei in patients treated at a regional cancer center.

MATERIALS AND METHODS

Fifteen cases of PMP were diagnosed during the five-year study period. The demographic and clinicopathological details were retrieved; the slides were reviewed and histological parameters reassessed. Descriptive statistics were used to express proportions. Continuous variables were recorded as mean (SD) or median (IQR). Kaplan-Meier (KM) curve was used to estimate overall survival.

RESULTS

Mean age for PMP was found to be 47.5 years for low grade Mucinous Carcinoma Peritonei (MCP), 54.2 years for high grade MCP, and 58 years for high grade MCP with signet ring cells. Most common overall presentation was abdominal distension in 53.3% (8/15) of cases, followed by acute appendicitis in 20% (3/15) cases. PMP was detected synchronous with the primary tumor in 9/15 cases (60%). Primary lesion in the appendix was grossly identified in 7/15 cases, while it was not explored in the remaining eight cases. Yet, by combined clinical, radiological, histopathological, and immunohistochemical analysis, we identified that most of the cases (14/15) had an appendiceal origin (93.3%). The overall survival for 12 months was 50% and for 18 months was 37%.

CONCLUSION

The surgeon and radiologist may well bear in mind the most common possibility of an appendiceal origin for PMP and resect the appendix, irrespective of the presence of a grossly or radiologically detectable lesions. We emphasize that immunohistochemistry helped to detect the site of origin even when the primary was occult.

Long term survival outcomes of surgery combined with hyperthermic intraperitoneal chemotherapy for perforated low-grade appendiceal mucinous neoplasms: A multicenter retrospective study

BACKGROUND

Low-grade appendiceal mucinous neoplasms (LAMN) are very rare, accounting for approximately 0.2%-0.5% of gastrointestinal tumors. We conducted a multicenter retrospective study to explore the impact of different surgical procedures combined with HIPEC on the short-term outcomes and long-term survival of patients.

METHODS

We retrospectively analyzed the clinicopathological data of 91 LAMN perforation patients from 9 teaching hospitals over a 10-year period, and divided them into HIPEC group and non-HIPEC group based on whether or not underwent HIPEC.

RESULTS

Of the 91 patients with LAMN, 52 were in the HIPEC group and 39 in the non-HIPEC group. The Kaplan-Meier method predicted that 52 patients in the HIPEC group had 5- and 10-year overall survival rates of 82.7% and 76.9%, respectively, compared with predicted survival rates of 51.3% and 46.2% for the 39 patients in the non-HIPEC group, with a statistically significant difference between the two groups (χ2 = 10.622, p = 0.001; χ2 = 10.995, p = 0.001). Compared to the 5-year and 10-year relapse-free survival rates of 75.0% and 65.4% in the HIPEC group, respectively, the 5-year and 10-year relapse-free survival rates of 48.7% and 46.2% in the non-HIPEC group were significant different between the two outcomes (χ2 = 8.063, p = 0.005; χ2 = 6.775, p = 0.009). The incidence of postoperative electrolyte disturbances and hypoalbuminemia was significantly higher in the HIPEC group than in the non-HIPEC group (p = 0.023; p = 0.044).

CONCLUSIONS

This study shows that surgery combined with HIPEC can significantly improve 5-year and 10-year overall survival rates and relapse-free survival rates of LAMN perforation patients, without affecting their short-term clinical outcomes.

Bland-Altman agreement analysis between CT predicted and surgical peritoneal cancer index in pseudomyxoma peritonei of appendiceal origin

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.

Low-Grade Pseudomyxoma Peritonei Behaving as a High-Grade Disease: A Case Series and Literature Review

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.

Health related quality of life is excellent and sustained at two decades after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in survivors of pseudomyxoma peritonei of appendiceal origin

INTRODUCTION

Optimal management of pseudomyxoma peritonei (PMP) is by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), which can achieve 20-year disease-free, and overall survival. There is limited information on the health-related quality of life (HRQOL) of PMP survivors beyond five years. We report longitudinal HRQOL in patients with PMP of appendiceal origin up to 17-years after their CRS and HIPEC in 2003-2004.

METHODS

Patients had HRQOL assessed with EORTC QLQ-C30 questionnaires pre-operatively, and at 1-, 10- and 17-years post-operatively. Comparisons in global health-related QOL (global-HRQOL) measures were made with (1) an age- and sex-matched normal European population, (2) between patients who underwent complete cytoreduction (CRS CC0/1) versus maximal tumor debulking (MTD), and (3) between those with and without peritoneal recurrence.

RESULTS

Forty-six patients underwent CRS & HIPEC for appendiceal PMP. One patient withdrew from the study. Of the 45 patients, 23 patients were alive at ten and 15 patients at 17-years post-operatively. 21/23 (91%) and 14/15 patients (93%) completed questionnaires respectively. Pre-operatively, patients had significantly lower global-HRQOL compared with the reference population. Over follow-up, patients experienced improvements in their global-HRQOL. By post-operative year-10 and -17, there was no difference between the global-HRQOL of patients and reference population. As expected, patients with CC0/1 and without peritoneal tumor recurrence had better global-HRQOL at ten- and 17-years post-operatively compared with those with MTD or recurrence.

CONCLUSIONS

Optimal CRS and HIPEC is an effective treatment for appendiceal PMP that can achieve long-term survival. HRQOL is excellent and maintained, in those who have CC0/1 without recurrence.

Long-term survival in patients with PMP: a single-institutional retrospective study from China

BACKGROUND

As the standard treatment for pseudomyxoma peritonei (PMP), cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) can significantly prolong the survival of PMP patients, and some patients can even achieve long-term survival (LTS) or clinical cure. The purpose of this study was to analyze the clinicopathological and treatment features of PMP patients with LTS and to explore the survival benefit factors of PMP patients.

METHODS

The clinicopathological and prognostic data of PMP patients who received CRS + HIPEC at our center from December 2004 to May 2023 were retrospectively analyzed. PMP patients were divided into LTS group (≥ 10 years) and short-term survival (STS) group (< 5 years) according to the length of natural history. Univariate and multivariate analyses were performed to explore the beneficial factors of PMP patients with LTS.

RESULTS

A total of 609 patients with PMP received CRS + HIPEC treatment at our center. Two-hundred one patients with PMP were included in the study after screening, including 39 patients (19.4%) in the LTS group and 162 patients (80.6%) in the STS group. In STS group and LTS group, median overall survival based on natural history was 29.2 (2.4-59.9) vs. 138.9 (120.3-416.7) months. Univariate analysis revealed 8 factors (P < 0.05) with statistically significant differences between the two groups: gender, chemotherapy history, previous surgical score, Karnofsky Performance Status score, pathological diagnosis, lymphatic metastasis, peritoneal cancer index, and completeness of cytoreduction (CC). Multivariate analysis identified only two factors independently associated with LTS of PMP patients: CC and pathological diagnosis.

CONCLUSION

Complete CRS and pathological features are two key factors affecting LTS in PMP patients.

[Incidental finding of appendiceal mucinous neoplasms]

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

Etiological analysis of infection after CRS + HIPEC in patients with PMP

BACKGROUND

Cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard treatment for pseudomyxoma peritonei (PMP). It can significantly prolong the survival of patients, but at the same time may increase the risk of postoperative infection.

METHOD

Patients with PMP who underwent CRS + HIPEC at our center were retrospectively analyzed. According to PMP patients, basic clinical data and relevant information of postoperative infection, we analyzed the common sites of postoperative infection, results of microbial culture and the antibiotics sensitivity. Univariate and multivariate analysis were performed to explore infection-related risk factors.

RESULT

Among the 482 patients with PMP, 82 (17.0%) patients were infected after CRS + HIPEC. The most common postoperative infection was central venous catheter (CVC) infection (8.1%), followed by abdominal-pelvic infection (5.2%). There were 29 kinds of microbes isolated from the culture (the most common was Staphylococcus epidermidis), including 13 kinds of Gram-positive bacteria, 12 kinds of Gram-negative bacteria, and 4 kinds of funguses. All the antibiotics sensitivity results showed that the most sensitive antibiotics were vancomycin to Gram-positive bacteria (98.4%), levofloxacin to Gram-negative bacteria (68.5%), and fluconazole to fungus (83.3%). Univariate and multivariate analysis revealed the infection independent risk factors as follow: intraoperative blood loss ≥ 350 mL (P = 0.019), ascites volume ≥ 300 mL (P = 0.008).

CONCLUSION

PMP patients may have increased infection risk after CRS + HIPEC, especially CVC, abdominal-pelvic and pulmonary infections. The microbial spectrum and antibiotics sensitivity results could help clinicians to take prompt prophylactic and therapeutic approaches against postoperative infection for PMP patients.

Personalising care for patients: implementing a treatment summary folder following cytoreductive surgery

BACKGROUND

A patient survey highlighted that patients treated with cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) at one NHS trust lacked confidence with the transition of care between teams. A personalised folder of treatment information was designed and given to patients prior to discharge.

AIMS

To obtain patient feedback on the implementation and content of the folder.

METHODS

30 consecutive patients were given the folder at discharge. Participants completed an online questionnaire to determine whether the information in the folder was appropriate, given at the right time in the pathway and enhanced confidence on discharge.

FINDINGS

90% response rate was achieved. Of the respondents, 96% strongly agreed/agreed that the folder was helpful, 4% disagreed; 92% strongly agreed/agreed that the amount of information was right, 8% preferred more information, none less; 74% agreed/strongly agreed that the folder was provided at the right time; 96% said that the content met their expectations.

CONCLUSION

Patients treated with CRS and HIPEC have specific needs related to their treatment. Implementation of the patient information folder at discharge increases patient confidence.

External multicentre validation of pseudomyxoma peritonei PSOGI-Ki67 classification

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare malignant disease. Adding of the Ki67 proliferation index to the PSOGI PMP classification provided two different subcategories of the extensive HG-PMP group (HG-PMP ≤15% and HG-PMP >15%) with different survival in a previous unicentric study. This study aims to carry out an external and multicentre validation of this new proposed classification.

METHOD

It was a prospective analysis of samples from a historical and international cohort of patients. A representative area with higher cellular density was used to determine the Ki67%. The Ki67 proliferation index (%) was determined in all the HG-PMP patients. A Cox proportional hazard models and multivariable COX models were used. The Kaplan-Meier method and the two-tailed log-rank test were used to analyse the effect of different PSOGI-Ki67 categories on OS and DFS. Its predictive accuracy was analysed using Harrel's C-index and the ROC curve. The calibration was performed using the calibration plots matching.

RESULTS

After exclusions, 349 patients were available for analysis. The 5-years OS were 86% for LG-PMP, 59% for HG-PMP≤15, 38% for HG-PMP>15 and 42% for SRC-PMP (p = 0.0001). The 5-years DFS were 49% for LG-PMP, 35% for HG-PMP≤15, 16% for HG-PMP>15 and 18% SRC-PMP (p = 0.0001). The discrimination capability of PSOGI-Ki67 was validated.

CONCLUSION

the PSOGI-Ki67 classification discriminates and predicts the OS and DFS in patients with PMP dividing the HG-PMP category into two well-defined sub-categories. The Ki67 proliferation index should be incorporated routinely in the pathology report for these patients.

Unravelling Peritoneal Carcinomatosis Using Cross-Sectional Imaging Modalities

Peritoneal carcinomatosis (PC) refers to malignant epithelial cells that spread to the peritoneum, principally from abdominal malignancies. Until recently, PC prognosis has been considered ill-fated, with palliative therapies serving as the only treatment option. New locoregional treatments are changing the outcome of PC, and imaging modalities have a critical role in early diagnosis and disease staging, determining treatment decision making strategies. The aim of this review is to provide a practical approach for detecting and characterizing peritoneal deposits in cross-sectional imaging modalities, taking into account their appearances, including the secondary complications, the anatomical characteristics of the peritoneal cavity, together with the differential diagnosis with other benign and malignant peritoneal conditions. Among the cross-sectional imaging modalities, computed tomography (CT) is widely available and fast; however, magnetic resonance (MR) performs better in terms of sensitivity (92% vs. 68%), due to its higher contrast resolution. The appearance of peritoneal deposits on CT and MR mainly depends on the primary tumour histology; in case of unknown primary tumour (3-5% of cases), their behaviour at imaging may provide insights into the tumour origin. The timepoint of tumour evolution, previous or ongoing treatments, and the peritoneal spaces in which they occur also play an important role in determining the appearance of peritoneal deposits. Thus, knowledge of peritoneal anatomy and fluid circulation is essential in the detection and characterisation of peritoneal deposits. Several benign and malignant conditions show similar imaging features that overlap those of PC, making differential diagnosis challenging. Knowledge of peritoneal anatomy and primary tumour histology is crucial, but one must also consider clinical history, laboratory findings, and previous imaging examinations to achieve a correct diagnosis. In conclusion, to correctly diagnose PC in cross-sectional imaging modalities, knowledge of peritoneal anatomy and peritoneal fluid flow characteristics are mandatory. Peritoneal deposit features reflect the primary tumour characteristics, and this specificity may be helpful in its identification when it is unknown. Moreover, several benign and malignant peritoneal conditions may mimic PC, which need to be considered even in oncologic patients.

Appendiceal Mucinous Neoplasms: From Clinic to Pathology and Prognosis

Appendiceal mucinous neoplasms have been classified differently over time causing confusion when comparing results between working groups in this field and establishing a prognosis of the disease. A historical perspective of the different classification systems of these tumors is essential for the understanding of the evolution of concepts and histopathological definitions that have led up to the present moment. We carried out a systematic review of the pathological classifications of appendiceal mucinous tumors and how they have included the new criteria resulting from clinical and pathological research. The latest classifications by PSOGI and AJCC 8th edition Cancer Staging have made a great effort to incorporate the new pathological descriptions and develop prognostic groups. The introduction of these new classification systems has posed the challenge of verifying how they adapt to our casuistry and which one defines best the prognosis of our patients. We reclassified our series of patients treated for mucinous appendiceal tumors with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy following the PSOGI and the AJCC 8th edition criteria and concluded that both classifications correspond well with the OS and DFS of these patients, with some advantage relative to the PSOGI classification due to a better histopathological description of the different groups.

Treatment outcome analysis of bevacizumab combined with cyclophosphamide and oxaliplatin in advanced pseudomyxoma peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare peritoneal malignant tumor syndrome. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is its standard treatment. However, there are few studies and insufficient evidence regarding systemic chemotherapy of advanced PMP. Regimens for colorectal cancer are often used clinically, but there is no uniform standard for late-stage treatment.

AIM

To determine if bevacizumab combined with cyclophosphamide and oxaliplatin (Bev+CTX+OXA) is effective for treatment of advanced PMP. The primary study endpoint was progression-free survival (PFS).

METHODS

Retrospective analysis was conducted on the clinical data of patients with advanced PMP who received Bev+CTX+OXA regimen (bevacizumab 7.5 mg/kg ivgtt d1, oxaliplatin 130 mg/m² ivgtt d1 and cyclophosphamide 500 mg/m² ivgtt d1, q3w) in our center from December 2015 to December 2020. Objective response rate (ORR), disease control rate (DCR) and incidence of adverse events were evaluated. PFS was followed up. Kaplan-Meier method was used to draw survival curve, and log-rank test was used for comparison between groups. Multivariate Cox proportional hazards regression model was used to analyze the independent influencing factors of PFS.

RESULTS

A total of 32 patients were enrolled. After 2 cycles, the ORR and DCR were 3.1% and 93.7%, respectively. The median follow-up time was 7.5 mo. During the follow-up period, 14 patients (43.8%) had disease progression, and the median PFS was 8.9 mo. Stratified analysis showed that the PFS of patients with a preoperative increase in CA125 (8.9 vs 2.1, P = 0.022) and a completeness of cytoreduction score of 2-3 (8.9 vs 5.0, P = 0.043) was significantly longer than that of the control group. Multivariate analysis showed that a preoperative increase in CA125 was an independent prognostic factor for PFS (HR = 0.245, 95%CI: 0.066-0.904, P = 0.035).

CONCLUSION

Our retrospective assessment confirmed that the Bev+CTX+OXA regimen is effective in second- or posterior-line treatment of advanced PMP and that adverse reactions can be tolerated. A preoperative increase in CA125 is an independent prognostic factor of PFS.

Pseudomyxoma peritonei and an incidental low-grade appendiceal mucinous neoplasm and neuroendocrine appendiceal collision tumour: a case report

Appendiceal collision tumours are extremely rare, with most reported cases describing tumours consisting of a mucinous component and a neuroendocrine component. Low-grade appendiceal mucinous neoplasms, in some cases, have a tendency to rupture and disseminate their mucin-producing cells throughout the abdominal cavity, leading to a clinical syndrome known as pseudomyxoma peritonei (PMP). We present the case of a 64-year-old male who initially presented with acute appendicitis and was subsequently found to have PMP and appendiceal malignancy. After several years of scans, surgical intervention and histological analysis, it became apparent that the appendiceal malignancy was comprised of distinct cell types. The patient underwent two rounds of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy, which resulted in a 2-year disease-free period. Unfortunately, the PMP recurred, having morphological changes consistent with a more aggressive disease process.

Assessing morbidity, mortality, and survival in patients with peritoneal carcinomatosis undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

OBJECTIVE

Peritoneal carcinomatosis (PC) indicates advanced stage cancer, which is generally associated with a poor outcome and a 6 to 12 months. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is an option for treating patients with primary PC, such as mesothelioma, or secondary PC, such as colorectal cancer (CRC) or pseudomixoma. Until recently, such patients were deemed untreatable. The purpose of this study was to assess the results of CRS + HIPEC in patients with PC. Postoperative complications, mortality and survival rates were evaluated according to the diagnosis.

RESULTS

Fifty-six patients with PC, undergoing full CRS + HIPEC between October 2004 and January 2020, were enrolled. The mortality rate was 3.8% and the morbidity rate was 61.5%. Complications were significantly higher in proportion to the duration of surgery (p<0.001). The overall survival rates, as shown in the Kaplan-Meyer curve, were respectively 81%, 74% and 53% at 12, 24 and 60 months. Survival rates according to each diagnosis for the same periods were 87%, 82% and 47% in patients with pseudomixoma, and 77%, 72% and 57% in patients with CRC (log-rank 0.371, p=0.543).

CONCLUSION

CRS with HIPEC is an option for pacients with primary or secondary PC. Although complication rates are high, a longer survival rate may be attained compared to those seen in previously published results; in some cases, patients may even be cured.

Combined ultrasonography and CT for prognosis and predicting clinical outcomes of patients with pseudomyxoma peritonei

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.

Significance of laparoscopic cytoreductive surgery for appendiceal pseudomyxoma peritonei with limited disease and low tumor burden

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.

Pseudomyxoma peritonei induced by a well-differentiated appendicular mucinous adenocarcinoma: An uncommon cause of isolated ascites in a young man patient

Pseudomyxoma peritonei (PMP) remains difficult to diagnose and has a reserved prognosis. Pseudomyxoma peritonei is a rare entity, of appendicular origin in the majority of cases. Its clinical symptomatology is not specific, and the diagnosis is evoked by imaging and surgery and confirmed by histology.

Prognostic Factors in Pseudomyxoma Peritonei with Emphasis on the Predictive Role of Peritoneal Cancer Index and Tumor Markers

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare peritoneal condition where mucus-secreting tumorous cells progressively produce a thick, gelatin-like substance. The prognosis of patients with PMP is determined by the degree of cellularity within the mucin (low-grade (LAMN) vs. high-grade (HAMN) histologic features) and by the extent of the disease.

METHODS

Prognostic relevance of tumor markers CA19-9 and CEA, gender, Peritoneal Cancer Index (PCI), and completeness of cytoreduction (CC) after cytoreductive surgery were evaluated on 193 consecutive PMP patients, based on a retrospective analysis of prospectively gathered data from a German tertial referral center.

RESULTS

We demonstrated that low PCI, CC0 status, low-grade histology, and female gender were independent positive prognostic factors for both overall survival (OS) and progression-free survival (PFS). Furthermore, LAMN patients with achieved CC0 status show significantly better OS and PFS compared to those with CC1 status (p = 0.0353 and p = 0.0026 respectively). In contrast, the duration and drug of hyperthermic intraperitoneal chemotherapy (HIPEC) were not prognostic in any comparison. Increased CA19-9 and CEA levels were significantly associated with HAMN cases, but also predicted recurrence in patients with low-grade histologies.

CONCLUSION

Our study confirmed the prognostic role of tumor markers and emphasized the importance of CC status and PCI in a large cohort of PMP- and LAMN patients.

Prognostic value of the ascites characteristics in pseudomyxoma peritonei originating from the appendix

Background

Pseudomyxoma peritonei (PMP) is a rare disease, with the overall survival (OS) influenced by many factors. To date, no ascites characteristics have been reported to predict OS of patients with PMP. The present study therefore aims to describe the ascites characteristics for PMP and identify prognostic factors for survival.

Methods

Between June 2010 and June 2020, 473 PMP patients who underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were included in a retrospective study. Survival analysis was performed with the Kaplan-Meier method by the log-rank test and a Cox proportional hazards model. Associations between categorical variables were analyzed using the chi-squared test.

Results

Among all included patients, 61% were women. The median OS was 47 months (range, 4-124 months) at the last follow-up in December 2020. Ascites characteristics can be divided into light blood ascites, "Jelly" mucus ascites, and faint yellow and clear ascites. Multivariate Cox analysis showed that the degree of radical surgery, ascites characteristics, and pathological grade were independently associated with OS in PMP patients. The chi-squared test documented that faint yellow "Jelly" ascites were related to low-grade PMP and light blood ascites were associated with high-grade PMP (P < 0.01).

Conclusions

Light blood ascites, incomplete cytoreduction surgery, and high-grade histopathology may predict poor OS in appendix-derived PMP.

Effect of standardized fluid management on cardiac function after CRS + HIPEC in patients with PMP: a single-center case-control study

OBJECTIVE

To investigate the effects of standardized fluid management (SFM) on cardiac function in patients with pseudomyxoma peritonei (PMP) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHOD

Patients with PMP who underwent CRS + HIPEC at our center were retrospectively analyzed. The patients were divided into control and study groups according to whether SFM was applied after CRS + HIPEC. We compared the preoperative and postoperative cardiac and renal function parameters, daily fluid volume three days after CRS, and cardiovascular-related adverse events. Univariate and multivariate analyses were performed to identify the indicators affecting clinical prognosis.

RESULT

Among the 104 patients, 42 (40.4%) were in the control group and 62 (59.6%) in the study group. There were no statistically significant differences between the two groups in the main clinicopathological characteristics, preoperative cardiac and renal function parameters, and CRS + HIPEC-related indicators. The incidences of cardiac troponin I (CTNI) > upper limit of normal (ULN), >2 × ULN, >3 × ULN, serum creatinine > ULN, and blood urea nitrogen > ULN were higher in the control group than in the study group (p < 0.05). The median daily fluid volume of the control group was higher than that of the study group 3 days after CRS (p < 0.05). Postoperative CTNI > 2 × ULN was an independent risk factor for serious circulatory adverse events. Survival analysis revealed pathological grading, completeness of cytoreduction score, and postoperative CTNI > ULN as independent prognostic factors.

CONCLUSIONS

SFM after CRS + HIPEC in patients with PMP may reduce cardiovascular adverse events risk and improve clinical outcomes.

Relapse of Pseudomyxoma Peritonei After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Pattern of Failure, Clinical Management and Outcomes

INTRODUCTION

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) have dramatically improved pseudomyxoma peritonei (PMP) prognosis, but treatment failures are still a concern. We investigated the pattern of failure, treatment and outcomes of progressing disease.

METHODS

A prospective database of 374 PMP patients was reviewed, and 152 patients relapsing after complete CRS/HIPEC were identified. PMP was graded according to the Peritoneal Surface Oncology Group International (PSOGI) classification. Hematogenous metastases and non-regional lymph node involvement were considered as systemic metastases.

RESULTS

Median follow-up was 78.3 months (95% confidence interval [CI] 66.7-90.4). PMP relapse involved the peritoneum in 112 patients, pleural cavity in 8, both peritoneum and pleura in 8, systemic sites in 11, and both peritoneum and systemic sites in 13 patients. Systemic metastases involved the lung (n = 14), liver (n = 4), distant nodes (n = 3), bone (n = 2), and both lung and distant nodes (n = 1). Survival after diagnosis of PMP relapse was independently associated with curative versus palliative treatment (hazard ratio [HR] 0.52, 95% CI 0.36-0.75; p = 0.001) and PSOGI histology (HR 1.80, 95% CI 1.19-2.74; p = 0.005), but was not influenced by site of failure (p = 0.444). Ten-year overall survival was 77.5% for 62 patients who had curative-intent surgery for PMP relapse, compared with 83.0% for 192 patients who had no recurrences (p = 0.154) and 26.1% for 90 patients who underwent palliative treatments (p = 0.001).

CONCLUSIONS

Relapse after CRS/HIPEC most commonly involves the peritoneum, but pleural recurrences and systemic metastases occur in a small but clinically relevant number of patients. In selected patients, surgical resection of recurrent disease can result in long survival, irrespective of sites of failure.

The contemporary management of peritoneal metastasis: A journey from the cold past of treatment futility to a warm present and a bright future

Peritoneal metastasis (PM) is often regarded as a less frequent pattern of spread; however, collectively across all spectra of primary tumors, the consequences of PM impact a large population of patients annually. Unlike other modes of metastasis, symptoms at presentation or during the treatment course are common, representing an additional challenge in the management of PM. Early efforts with chemotherapy and incomplete surgical interventions transiently improved symptoms, but durable symptom control and survival extension were rare, which established a perspective of treatment futility for PM through most of the 20th century. Notably, the continued development of better systemic therapy combinations, optimization of cytoreductive surgery (CRS), and rigorous investigation of combining regional therapy-specifically hyperthermic intraperitoneal chemotherapy-with CRS, have resulted in more effective multimodal treatment options for patients with PM. In this article, the authors provide a comprehensive review of the data establishing the contemporary approach for tumors with a high frequency of PM, including appendix, colorectal, mesothelioma, and gastric cancers. The authors also explore the emerging role of adding hyperthermic intraperitoneal chemotherapy to the well established paradigm of CRS and systemic therapy for advanced ovarian cancer, as well as the recent clinical trials identifying the efficacy of poly(adenosine diphosphate ribose) polymerase maintenance therapy. Finally, recent data are included that explore the role of precision medicine technology in PM management that, in the future, may help further improve patient selection, identify the best systemic therapy regimens, detect actionable mutations, and identify new targets for drug development.

Incidental diagnosis of pseudomyxoma peritonei by laparoscopy: a rare case from Syria

Pseudomyxoma peritonei (PMP) is a rare malignancy of the abdomen, which is usually described as a gelatinous peritoneal fluid. A 33-year-old man came to the ER complaining of recurring abdominal pain with abdominal distention for the past 3 months. Abdominal ultrasound revealed moderate amount of turbulent ascitic fluid with septations, in addition to a mass with irregular margins consisting of liquid and cysts. Abdomen and pelvis computed tomography scan showed free abdominal fluid. A decision was made for abdominal diagnostic laparoscopy with biopsies from the peritoneum, mesenteries and the gelatinous fluid. We could not investigate all the abdominal cavities and appendix due to the presence of severe adhesions and tuberculosis suspension. The pathology report indicated PMP. The patient was referred to an oncologist for chemotherapy consultation. The diagnosis can be challenging, as the symptoms and signs vary from patient to another; most cases may be asymptomatic and discovered incidentally during laparoscopy.

Alginate Microsphere Encapsulation of Drug-Loaded Nanoparticles: A Novel Strategy for Intraperitoneal Drug Delivery

Alginate hydrogels have been broadly investigated for use in medical applications due to their biocompatibility and the possibility to encapsulate cells, proteins, and drugs. In the treatment of peritoneal metastasis, rapid drug clearance from the peritoneal cavity is a major challenge. Aiming to delay drug absorption and reduce toxic side effects, cabazitaxel (CAB)-loaded poly(alkyl cyanoacrylate) (PACA) nanoparticles were encapsulated in alginate microspheres. The PACAlg alginate microspheres were synthesized by electrostatic droplet generation and the physicochemical properties, stability, drug release kinetics, and mesothelial cytotoxicity were analyzed before biodistribution and therapeutic efficacy were studied in mice. The 450 µm microspheres were stable at in vivo conditions for at least 21 days after intraperitoneal implantation in mice, and distributed evenly throughout the peritoneal cavity without aggregation or adhesion. The nanoparticles were stably retained in the alginate microspheres, and nanoparticle toxicity to mesothelial cells was reduced, while the therapeutic efficacy of free CAB was maintained or improved in vivo. Altogether, this work presents the alginate encapsulation of drug-loaded nanoparticles as a promising novel strategy for the treatment of peritoneal metastasis that can improve the therapeutic ratio between toxicity and therapeutic efficacy.

Transfusion of stored autologous blood in patients with low-grade pseudomyxoma peritonei: A retrospective analysis of its safety and outcome

Background

Pseudomyxoma peritonei is a rare disease that presents as a malignant tumor on the peritoneal surface. Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy is the standard treatment for this disease and frequently requires a red blood cell transfusion. However, due to the limited collection and supply of allogeneic blood, surgical treatment may be delayed due to inadequate preparation of allogeneic blood in the course of clinical treatment. This study aimed to evaluate the safety and efficacy of transfusion of stored autologous blood in patients with low-grade pseudomyxoma peritonei.

Methods

Pseudomyxoma peritonei patients who received cytoreductive surgery combined with heat-infused peritoneal chemotherapy were divided into two groups: transfusion of allogeneic blood and transfusion of stored autologous blood. A comparison of the differences in multiple factors between the two groups was performed, including tumor recurrence, survival time, hemoglobin and hematocrit levels, coagulation function (prothrombin time, activated partial thromboplastin time, and fibrinogen), total hospital stay duration, and incidence of serious adverse events after surgery.

Results

Propensity scores matching analysis yielded 34 patients with allogeneic blood transfusion and 34 patients with stored autologous blood transfusion. Comparison analysis did not show statistical differences in several factors, including age, tumor grade, tumor recurrence rate after surgery, etc., between the two groups. The cytoreductive degree was considered an independent risk factor for tumor recurrence. The pseudomyxoma peritonei patients in the autologous transfusion group had a higher 5-year survival rate and a longer survival time. Moreover, transfusion of stored autologous blood did not increase the rate of tumor recurrence, or the total hospital stay duration after surgery, the hemoglobin level and coagulation function were well stabilized within 24 h after surgery, and there was a low incidence of serious adverse events.

Conclusion

The clinical application of transfusion of stored autologous blood in pseudomyxoma peritonei patients is safe and effective.

A Case Report of Pseudomyxoma Peritonei Arising From Primary Mucinous Ovarian Neoplasms

Pseudomyxoma peritonei (PMP) is a rare manifestation of primary mucinous neoplasms. We report two rare cases of PMP originating from mucinous primary ovarian neoplasms. The case series discusses the cases of female patients aged 86 and 52 years who presented with worsening dyspepsia, abdominal distension, pelvic pain, and altered bowel habits. Both of the patients underwent evaluation comprising cancer antigen-125 (CA-125) levels, ultrasound (US) examination of the abdomen and the pelvis, tumor markers, cytological evaluation, and contrast-enhanced computed tomography (CECT) of the pelvis and abdomen. Patients were diagnosed to have pseudomyxoma peritonei arising from mucinous ovarian tumors. Patients were referred to the surgical department and were successfully managed with repeated removal of mucinous material. The present case report highlights the significant radio-pathologic characteristics of PMP, which originated from mucinous ovarian tumors.

Pleural decortication and hyperthermic intrathoracic chemotherapy for pseudomyxoma

Aim: Pleural dissemination of pseudomyxoma peritonei (PMP) is an extremely rare diagnosis, for which no standard therapy is available.Methods: We describe the successful treatment of a 67-year-old male diagnosed with left-sided intrapleural dissemination of PMP (low-grade appendiceal mucinous neoplasm), 2 years after treatment of abdominal PMP with cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy. Treatment consisted of extended pleural decortication (ePD) and oxaliplatin-based hyperthermic intrathoracic chemotherapy (HITHOC). The patient is doing well without complications or signs of recurrence, 26 months after thoracic surgery.Conclusion: ePD in combination with HITHOC is a valuable treatment for thoracic PMP.

Comprehensive Treatment Algorithms of the Swiss Peritoneal Cancer Group for Peritoneal Cancer of Gastrointestinal Origin

Peritoneal cancer (PC) is a dire finding, yet in selected patients, long-term survival is possible. Complete cytoreductive surgery (CRS) together with combination immunochemotherapy is essential to achieve cure. Hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are increasingly added to the multimodal treatment. The Swiss Peritoneal Cancer Group (SPCG) is an interdisciplinary group of expert clinicians. It has developed comprehensive treatment algorithms for patients with PC from pseudomyxoma peritonei, peritoneal mesothelioma, gastric, and colorectal origin. They include multimodal neoadjuvant treatment, surgical resection, and palliative care. The indication for and results of CRS HIPEC and PIPAC are discussed in light of the current literature. Institutional volume and clinical expertise required to achieve best outcomes are underlined, while inclusion of patients considered for CRS HIPEC and PIPAC in a clinical registry is strongly advised. The present recommendations are in line with current international guidelines and provide the first comprehensive treatment proposal for patients with PC including intraperitoneal chemotherapy. The SPCG comprehensive treatment algorithms provide evidence-based guidance for the multimodal care of patients with PC of gastrointestinal origin that were endorsed by all Swiss clinicians routinely involved in the multimodal care of these challenging patients.

Misdiagnosed appendiceal mucinous neoplasms and primary ovarian mucinous tumors present with different pre- and intraoperative characteristics

Objective

To identify the differences between the pre- and intraoperative characteristics in misdiagnosed appendiceal mucinous neoplasms (AMNs) and those in primary ovarian mucinous tumors (POMTs) and to establish an effective model for differentiating AMNs from pelvic mucinous tumors.

Methods

This study enrolled 70 AMN patients who were misdiagnosed with ovarian tumors and 140 POMT patients who were treated from November 1998 to April 2021 at Peking Union Medical College Hospital. The clinical features and operative findings of the two groups of patients were collected and compared.

Results

There were significant differences in age and menopausal status, but no difference in the patients’ clinical manifestations between the two groups. The preoperative serum CA125 and CA199 levels were not different between the two groups. The CEA level (31.04 ± 42.7 vs. 7.11 ± 24.2 ng/ml) was higher in the misdiagnosed AMN group (P < 0.001). The AMNs were smaller than the POMTs that were measured preoperatively by ultrasonography (US) (P<0.05) and measured at surgery (P<0.05). Furthermore, the patients with AMNs more commonly had multinodularity and ascites noted on the preoperative US (P<0.001), on CT (P<0.001), and at surgery (P< 0.001). The two groups also differed in the presence of bilateral disease, in the appendiceal appearance and peritoneal dissemination. Subsequently, a prediction model was developed using multivariable logistic regression, which was evaluated through internal validation.

Conclusions

The suspicion of a nongenital organs originated tumor especially origing from appendiceal should be considered in a patient who is older, tumor size less than 12cm, multinodular, presence of mucinous ascites, and elevated serum CEA levels. Bilateral ovarian involvement, peritoneal dissemination, and an abnormal appendiceal appearance found during surgery were the typical features associated with AMNs.

Prognosis for Young Females with Pseudomyxoma Peritonei of Appendiceal Origin and Unilateral or Bilateral Ovaries Preserved During Cytoreductive Surgery

Objective

To determine prognosis for young female patients with peritoneal pseudomyxoma (PMP) of appendiceal origin and unilateral or bilateral ovaries preserved during cytoreductive surgery (CRS).

Methods

Clinical data of female patients treated with CRS with or without hyperthermic intraperitoneal chemotherapy (HIPEC) at the Aerospace Center Hospital, Beijing between January, 2009 and December, 2019 were retrospectively reviewed. Patients had no changes in the bilateral ovaries on gross pathological observations or biopsy during CRS, and normal ovarian function. The demographic and clinical characteristics and prognosis of women with ovaries preserved (ovarian preservation group) or resected (ovarian resection group) during CRS were compared. Independent prognostic factors for survival were identified using univariate and multivariate analysis.

Results

40 patients were included in the final analysis. 19 patients chose ovarian preservation while 21 patients underwent ovarian resection. Completeness of cytoreduction (CCR) scores were CCR-0/1. There were significant differences in age (<40 vs. ≥40), symptoms, intraoperative HIPEC (Y vs. N), and histopathologic subtype of PMP (low-grade vs. high-grade) (p < 0.001) between patients in the ovarian preservation and ovarian resection groups. In the ovarian preservation group, median overall survival (OS) was 59 months (range, 53–65 months), and the 5-year survival rate was 37.9%. Median disease-free survival (DFS) was 13 months (range, 9–17 months), and the 5-year recurrence rate was 87.4%. In the ovarian resection group, the 5-year survival rate was 87.7%, and the 5-year recurrence rate was 18.3%. Median OS and median DFS were not reached. In patients with low-grade PMP, median DFS was significantly longer in patients with ovarian resection compared to ovarian preservation (p < 0.001). Univariate analysis showed histopathologic subtype of PMP (low-grade vs. high-grade, p < 0.001) was significantly associated with OS and DFS. On multivariate analysis, high-grade histopathologic subtype of PMP was an independent predictor of poor prognosis (OS and DFS).

Conclusion

Histopathologic subtype of PMP represents an independent predictor of prognosis in female patients with PMP of appendiceal origin and unilateral or bilateral ovaries preserved during CRS. These findings imply that ovarian preservation is a more suitable option for young females with low-grade PMP compared to high-grade PMP. Further prospective studies should be done investigating the role of resection of uninvolved ovaries in PMP.

The Role of Microorganisms in Appendiceal Pseudomyxoma Peritonei: A Review

Pseudomyxoma peritonei (PMP) is a rare clinical syndrome. It originates from neoplasms of the appendix and leads to the formation of peritoneal implants and the accumulation of mucinous ascites. PMP represents a spectrum of low to high-grade disease. Despite aggressive management, many PMP patients recur, leading to debilitating symptoms and few treatment options. Therefore, scientists have continued to look for ways to improve treatment and further understand disease pathogenesis. Microorganisms were previously hypothesized to play a role in PMP progression and development. Hence, antibacterial treatment was suggested by some authors, but the data were limited. In this paper, we review the current data on the role of bacteria in PMP, discuss the significance, and suggest possible solutions to the inherent challenges in these studies. Given the limitations of the discussed studies, we remain skeptical about introducing novel antibacterial treatment into clinical practice at this time; however, the available data are valuable and indicate that more research into the molecular mechanisms of PMP is needed.

Comprehensive Understanding and Evolutional Therapeutic Schemes for Pseudomyxoma Peritonei: A Literature Review

Pseudomyxoma peritonei is an infrequent solid tumor in clinical practice. The low morbidity and deficient understanding of this mucus-secreting malignant disease increase the risks of delayed identification or uncontrollable deterioration. In quite a lot cases, patients go through complete cytoreduction surgery and hyperthermic intraperitoneal chemotherapy could receive a long time survival over 5 years. But the recurrence rate is also hard to overlook. Unlike other types of cancer, the standard treatment for this considerable groups has not been confirmed yet. With the advanced medical progression, studies have been carrying out based on pathogenesis, biological characters, and mutated gene location. All but a few get statistical survival benefits, let alone the breaking progress on research or therapeutic practice in the field. We try to give a comprehensive exposition of pseudomyxoma peritonei around the epidemiology, radiologic features, clinical manifestation, present treatment and promising schemes, hoping to arise much attention and reflection on the feasible solutions, especially for the recrudescent part.

Management of peritoneal pseudomyxoma in Pregnant Women: A case report and review of the literature

The incidence of neoplasia during pregnancy is low, 1/1000 pregnancies. The most common cancers diagnosed during pregnancy are breast and cervical cancer. Pseudomyxoma peritonei (PMP) is a rare syndrome (1/1 000 000) characterized by the presence of gelatinous ascites and disseminated intra-peritoneal mucinous tumors. The origin of this syndrome is, in most of cases, a tumor of the appendix. A PMP diagnosis during pregnancy is an extremely rare event. We present the medical history of a 34-year-old woman diagnosed with a PMP at 29 weeks of amenorrhea, during the management of an ovarian masse. We preserved the pregnancy until 37 weeks of amenorrhea. She had a vaginal delivery. At 4 weeks post-partum, she had an extensive cytoreduction with intraperitoneal chemotherapy. We present literature review of PMP discover during pregnancy and a discussion about treatment of these PMP. We also discuss management of an ovarian masse diagnosis during pregnancy.

Radiomics analysis based on CT's greater omental caking for predicting pathological grading of pseudomyxoma peritonei

The objective of this study was to predict the preoperative pathological grading and survival period of Pseudomyxoma peritonei (PMP) by establishing models, including a radiomics model with greater omental caking as the imaging observation index, a clinical model including clinical indexes, and a combined model of these two. A total of 88 PMP patients were selected. Clinical data of patients, including age, sex, preoperative serum tumor markers [CEA, CA125, and CA199], survival time, and preoperative computed tomography (CT) images were analyzed. Three models (clinical model, radiomics model and combined model) were used to predict PMP pathological grading. The models’ diagnostic efficiency was compared and analyzed by building the receiver operating characteristic (ROC) curve. Simultaneously, the impact of PMP’s different pathological grades was evaluated. The results showed that the radiomics model based on the CT’s greater omental caking, an area under the ROC curve ([AUC] = 0.878), and the combined model (AUC = 0.899) had diagnostic power for determining PMP pathological grading. The imaging radiomics model based on CT greater omental caking can be used to predict PMP pathological grading, which is important in the treatment selection method and prognosis assessment.

Spectrum of MRI Features of Mucin-producing Neoplasms in the Abdomen and Pelvis

Mucin-producing neoplasms in the abdomen and pelvis are a distinct entity, separate from simple fluid-containing neoplasms and loculated fluid collections. Mucin is a thick gelatinous substance and-owing to its high water content-has imaging features that can be mistaken for those of simple fluid-containing neoplasms with multiple imaging modalities. However, mucin-producing neoplasms arise from specific organs in the abdomen and pelvis, with unique imaging appearances, knowledge of which is important to guide accurate diagnosis and management. With its large field of view and high soft-tissue resolution, MRI has advantages over other imaging modalities in characterizing these neoplasms. The authors focus on the spectrum of MRI features of such mucin-producing neoplasms and illustrate how-despite a varied organ origin-some of these neoplasms share similar MRI and histopathologic features, thereby helping narrow the differential diagnosis. One common finding in these tumors is that the presence of internal complexity and solid enhancing components increases as the degree of malignant transformation increases. Lack of internal complexity generally indicates benignity. These tumors have a varied range of prognosis; for example, a low-grade appendiceal mucinous neoplasm is indicative of a good prognosis, while a mucinous tumor of the rectum is known to manifest at an early age with aggressive behavior and poorer prognosis compared with its nonmucinous counterpart. Online supplemental material is available for this article. ^©RSNA, 2022.

Pancreatic Cystic Neoplasms and Pregnancy: A Systematic Review of Surgical Cases and a Case Report of a Fully Laparoscopic Distal Pancreatectomy

BACKGROUND

Mucinous cystic neoplasms and solid pseudopapillary neoplasms are the most common pancreatic tumors occurring in women of fertile age and in pregnant women. The aim of this study is to provide an updated literature review on this association and to present a fully laparoscopic resection of a pregnancy-associated pancreatic cystic neoplasm.

MATERIALS AND METHODS

A systematic literature review was performed using PubMed (MEDLINE), Scopus, Ovid, ISI Web of Science, and Google Scholar for searching. The syntax was (pancr*) AND (cyst*) AND (pregn*) AND (tumor). Only English-language articles describing pancreatic surgical resections were included.

RESULTS

Forty-seven case reports were included. The mean age of the patients was 29.6±5.3. Nine patients (20%) required emergency surgery, 4 (9%) due to cyst rupture, and 5 (11%) due to hemorrhage. Four patients (9%) suffered a miscarriage, and 2 (5%) opted for pregnancy termination; the rest of the women delivered a healthy newborn (86%, n=36). Thirty percent (n=14) of the resected neoplasms were malignant, and among mucinous cystic lesions, this raised to 45% (n=11). All patients diagnosed during the third trimester were resected postpartum, whereas 26/34 (76%) of patients diagnosed during the first 2 trimesters underwent surgery before delivery.

CONCLUSIONS

The most worrisome complications in pregnancy-associated pancreatic cysts are bleeding or rupture. Mucinous cystic neoplasm has a tendency to grow during pregnancy. A postpartum resection was generally preferred when the cystic neoplasm was diagnosed during the third trimester. This report is the first to describe a fully laparoscopic pancreatic resection.

A case of pancreaticoduodenectomy and partial hepatic resection as repeat cytoreductive surgery for recurrent pseudomyxoma peritonei

Background

For recurrent pseudomyxoma peritonei (PMP), repeat cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) can provide survival benefits if patients are carefully selected. We describe a case of pancreaticoduodenectomy and partial liver resection (HPD) as the repeat CRS for a recurrent tumor that infiltrated the pancreatic head around the hepatic hilum. This is the first report of HPD for recurrent PMP.

Case presentation

The patient was a 58-year-old male without comorbidities. In 2001, he was diagnosed with PMP at the time of laparoscopic cholecystectomy. In 2004, CRS, including total peritoneal resection, pyloric gastrectomy, splenectomy, and right hemicolectomy with HIPEC was performed (peritoneal cancer index (PCI) = 28). In 2008, the first repeat CRS with HIPEC was performed (PCI = 14). In 2016, fourth repeat CRS, including partial hepatectomy with HIPEC for recurrence of the round ligament of the liver, was performed. In 2017, a tumor of 5 cm in size was observed from the hepatic hilum to the pancreatic head, which infiltrated the main pancreatic duct. Other tumors 2 cm in size were observed (PCI = 7). We performed the fifth repeat CRS, including HPD. The adhesions of the small intestine from around the liver to the lower abdomen were detached for the reconstruction of pancreatojejunostomy and cholangiojejunostomy. The uncinate approach was applied for the pancreatic head resection because it was difficult to identify the cranial part of the pancreas due to adhesions in the hepatoduodenal ligament and the omental bursa. We approached to the origin of the extrahepatic Glissonean pedicle by resecting a part of the liver around the hepatic hilum using transhepatic hilar approach. A complete cytoreduction was achieved. The postoperative pathological diagnosis was a recurrence of PMP, which is equivalent to peritoneal mucinous carcinomatosis. He was discharged on the 22nd postoperative day without major postoperative complications. The patient survived without recurrence four years after HPD.

Conclusions

Even for recurrence around the hepatic hilum and the pancreatic head, repeat CRS can be safely performed by applying the techniques of hepatobiliary pancreatic surgery.

Prognostic Value of CEA, CA19-9, CA125, CA724, and CA242 in Serum and Ascites in Pseudomyxoma Peritonei

Purpose

To investigate the expression of carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), CA19-9, CA724, and CA242 in serum and ascites of pseudomyxoma peritonei (PMP) patients and evaluate the predictive value of these elevated biomarkers in pathological grade, completeness of cytoreduction (CC), and survival.

Methods

From May 2009 to October 2019, a total of 512 patients diagnosed with PMP through pathology in Aerospace Center Hospital were enrolled. The serum and ascites tumor biomarkers were obtained. The diagnostic values between serum and ascites biomarkers in pathology and CC were compared by the receiver operating characteristic (ROC) curves. The correlation between pathology, cytoreduction, and biomarkers was calculated by univariate and multivariate logistic regression. The associations between different numbers of elevated biomarkers and survival status were examined using univariate and multivariate backward Cox proportional hazard regression models.

Results

The results showed that the areas under the ROC curves (AUROC) in the diagnosis of CC were 0.798 (95% CI: 0.760-0.836) and 0.632 (95% CI: 0.588-0.676) in serum and ascites biomarkers, respectively. The elevated serum and ascites biomarkers were independent risk factors for both pathology and CC. The 1-year, 3-year, and 5-year survival rates were 89.07%, 73.22%, and 66.94%, respectively. Longer survival was observed in patients who had less than two elevated serum biomarkers compared with those with 2-3 and 4-5 elevated serum biomarkers (p < 0.001).

Conclusion

CEA, CA125, CA19-9, CA724, and CA242 in serum and ascites can be used to judge the severity and predict the resectability. Furthermore, different numbers of elevated biomarkers can help determine the prognosis of PMP.