The Prognostic Impact of Pathology on Patients With Pseudomyxoma Peritonei Undergoing Debulking Surgery: A Systematic Review and Meta-Analysis of Retrospective Studies

Background: Pseudomyxoma peritonei (PMP) is a rare clinical condition with fatal outcomes, which is characterized by the progressive accumulation of mucinous ascites and peritoneal implants. Some studies have reported the effect of PMP biology on patient outcome. The objective of this study was to analyze published articles focusing on the impact of pathology on the prognosis of PMP patients undergoing debulking.

Methods: Data from all studies regarding the prognosis of patients, with different pathologies, who underwent debulking surgery were analyzed. We searched PubMed, the Wiley Online Library, Ovid, and the Cochrane Library (through January 2020). Studies were confined to those articles written in English. Five studies were identified, and the differences in 5-year survival rates were analyzed according to the Kaplan–Meier survival curves. The hazard ratios (HRs) of the 5-year survival rates were calculated.

Results: The mean and median 5-year survival rates of all patients were 39 and 40%, respectively. The median overall survival was 49.3 months. The mean 5-year survival rates of low-grade PMP was 45.2%. The five studies had sufficient data to calculate HRs from the 5-year survival rates data, and three had HRs lower than 1. The total HRs was 0.54, with a 95% CI between 0.33 and 0.89 (P = 0.01).

Conclusions: Among PMP patients receiving debulking surgery who are not able to undergo complete cytoreductive surgery, low-grade biological PMP had a better prognosis than high-grade PMP.

Pseudomyxoma peritonei induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer: a case report and literature review

Background

Pseudomyxoma peritonei (PMP) is a disease involving the peritoneum characterized by the production of large quantities of mucinous ascites. PMP has a low incidence, is difficult to diagnose, and has a guarded prognosis. PMP induced by low-grade appendiceal mucinous neoplasm is extremely rare, and PMP accompanied by rectal cancer is even rarer.

Case presentation

We present a unique case of a 70-year-old male with PMP induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer. The patient’s clinical, surgical, and histologic data were reviewed. The patient had persistent distended abdominal pain without radiating lower back pain, abdominal distension for 1 month, and no exhaustion or defecation for 4 days. A transabdominal ultrasound-guided biopsy was performed on the first day. The patient received an emergency exploratory laparotomy because of increased abdominal pressure. We performed cytoreductive surgery, enterolysis, intestinal decompression, special tumour treatment and radical resection of rectal carcinoma. The postoperative course was uneventful. The postoperative histological diagnoses were PMP, low-grade appendiceal mucinous neoplasm and rectal medium differentiated adenocarcinoma. At the 1-year follow-up visit, no tumour recurrence was observed by computed tomography (CT). We also performed a literature review.

Conclusions

We should be aware that PMP can rarely be accompanied by rectal cancer, which represents an easily missed diagnosis and increases the difficulty of diagnosis and treatment. Additionally, there are some typical characteristics of PMP with respect to diagnosis and treatment.

Pseudomyxoma extraperitonei in horseshoe kidney masquerading as renal hilar tumor: a case report

Pseudomyxoma peritonei, a rare condition consisting of intraperitoneal mucinous tumors and ascites, most commonly arises from mucinous tumors of the appendix. Very rarely, mucinous deposits arise in the retroperitoneum without intraperitoneal involvement. This has been termed pseudomyxoma extraperitonei. It is a rare and poorly understood condition that is heterogeneous in its clinical behavior, and only a few cases presenting as localized disease in the retroperitoneum have been reported. In this paper, we report the first case of pseudomyxoma extraperitonei presenting as a simple renal hilar mass and mimicking a tumor of renal origin in a horseshoe-kidney patient. The patient underwent isthmusectomy and nephrectomy. Immunohistochemical staining suggested appendiceal origin. She remained alive without adjuvant therapy postoperatively, and no evidence of recurrence was present for 25 months.

Palliative Radiation Therapy for Symptom Control in an Advanced Case of Pseudomyxoma Peritonei

Pseudomyxoma peritonei (PP) is a rare clinical condition characterized by progressive mucinous ascites, which is typically caused by a mucin-producing neoplasm. Reports of radiation therapy (RT) in the management of PP are limited. We report a unique case of a 62-year-old woman with severe, end-stage, recurrent PP and a large, mucin-secreting mass protruding through her abdominal wall. Low-dose, hypofractionated palliative RT was administered for symptom control with the hope of improving her quality of life. We suggest that radiation therapy be considered in the comprehensive palliative management of patients with PP.

"The Jelly Belly": Diagnostic Dilemmas and Current Concepts

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare and poorly understood clinicopathological entity characterized by gelatinous ascites with neoplastic or non-neoplastic mucinous implants in the peritoneum. Although its origin was debated, current evidence in literature favours the appendix as the origin of the disease, over the ovaries. The changing terminologies in the classification of this entity pose diagnostic and management challenges.

CASE REPORTS

Herein, we report three cases of PMP in postmenopausal women, their clinical presentation, pathological staging based on the peritoneal tumor deposits and the treatment administered. Two patients recovered uneventfully, while one had recurrence of adenocarcinoma.

CONCLUSION

The rarity of this disease and the diagnostic challenges associated with it are discussed with an emphasis on the current concepts in its origin and management. Appropriate classification and complete removal of the tumor is mandated to prevent disease-related mortality.

Rare Presentation of Pseudomyxoma Retroperitonei: Stretching the Limits

A 55-year-old woman presented with a mucopurulent sinusal discharge from the right supragluteal region, with symptoms over the previous five months. This abscess began as a slowly swelling growth, which eventually turned into a discharging sinus, and she was diagnosed with a gluteal abscess. The patient underwent incisional drainage, and intra-operatively, the sinus tract could be seen extending to the retroperitoneum. A subsequent CT scan and an MRI of the abdomen revealed a large heterogeneous retroperitoneal cystic mass on the right side of midline, extending inferiorly into the anterior thigh along the iliopsoas. Superiorly, a tubular projection extended from the lesion, indenting the ileocaecal junction, while a fluid filled cutaneous fistulous tract was seen, extending to the right flank. A diagnosis of pseudomyxoma retroperitonei, likely of retrocaecal appendicular origin, was proposed. An explorative laparotomy with an appendectomy, and the evacuation of the retroperitoneal collection were completed. The subsequent histopathology confirmed the diagnosis of appendicular mucinous cystadenoma, with pseudomyxoma retroperitonei.

Can a Benefit be Expected from Surgical Debulking of Unresectable Pseudomyxoma Peritonei?

PURPOSE

This study evaluated the role of surgical debulking in improving pseudomyxoma peritonei (PMP)-related symptoms if complete cytoreductive surgery (CCRS) of huge PMP is unachievable.

METHODS

This was a retrospective analysis of a prospective database of all patients in our tertiary care center treated for PMP between 1992 and 2014. All cases of surgical debulking in patients scheduled for CCRS that proved unachievable during the operation were selected for the present study.

RESULTS

Among the 338 patients operated on for PMP, 39 (11.5 %) had undergone surgical debulking because CCRS was unachievable. All of these patients were symptomatic before surgery, and the median PCI was 32 (5-39). More than 80 % of the disease burden was resected in 23 patients (59 %). Mortality and major morbidity rates were 2.5 and 23 %, respectively. After debulking surgery, symptoms gradually subsided over a median time of 23 months and 50 % of the patients no longer experienced PMP-related symptoms after a median follow-up of 24.5 months. After a median follow-up of 46.4 months (range 3-120), median overall (OS) and progression-free (PFS) survival times were 55.5 and 20 months, respectively. Five-year OS and PFS rates were 46 and 11 %, respectively.

CONCLUSIONS

Aggressive debulking surgery in case of unachievable CCRS for huge PMP can offer prolonged relief of PMP-related symptoms and long-term survival, in experienced centers that are able to be sufficiently aggressive to resect the major part of the disease, and conservative enough to achieve low mortality and good quality of life.

Drug Sensitivity Testing in Cytoreductive Surgery and Intraperitoneal Chemotherapy of Pseudomyxoma Peritonei

Background

Cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) is an established therapy for pseudomyxoma peritonei (PMP). However, the role of IPC is unclear. By ex vivo assessment of PMP tumor cell sensitivity to cytotoxic drugs, we investigated the basis for IPC drug selection and the role of IPC in the management of PMP.

Methods

Tumor cells were prepared by collagenase digestion of tumor tissue from 133 PMP patients planned for CRS and IPC. Tumor cell sensitivity to oxaliplatin, 5FU, mitomycin C, doxorubicin, irinotecan, and cisplatin was assessed in a 72-h cell-viability assay. Drug sensitivity was correlated to progression-free survival (PFS) and overall survival (OS).

Results

Samples from 92 patients were analyzed successfully. Drug sensitivity varied considerably between samples. Peritoneal mucinous carcinomatosis (PMCA), compared with PMCA intermediate or disseminated peritoneal adenomucinosis, was slightly more resistant to platinum and 5FU and tumor cells from patients previously treated with chemotherapy were generally less sensitive than those from untreated patients. Multivariate analysis showed patient performance status and completeness of CRS to be prognostic for OS. Among patients with complete CRS (n = 61), PFS tended to be associated with sensitivity to mitomycin C and cisplatin (p ≈ 0.06). At the highest drug concentration tested, the hazard ratio for disease relapse increased stepwise with drug resistance for all drugs.

Conclusions

Ex vivo assessment of drug sensitivity in PMP provides prognostic information. The results suggest a role for IPC as therapeutic adjunct to CRS and for individualization of IPC by pretreatment assessment of drug sensitivity.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-015-4675-0) contains supplementary material, which is available to authorized users.

Pseudomyxoma peritonei extending to the lower extremity: a case report

Pseudomyxoma peritonei is characterized by mucinous ascites originating from a mucin-producing neoplasm; however, even the definition is still under debate. Tumor deposits extend and ultimately engulf the entire cavity, causing death from cachexia due to limited intestinal movement. Here, we report a unique case of an 80-year-old woman with pseudomyxoma peritonei, which extended to the lower extremity mimicking infectious condition. The patient survived for a long time without bowel obstruction despite having the histologic subtype that has an unfavorable prognosis. The extremity lesion was treated with limited extensive surgery. The origin of the disease and the mechanism of extension to the extremity could not be clarified. Clinicians should be aware of the original disease entity and this unusual presentation and determine its mechanism and the best management strategy.

Controversy and consensus on the management of patients with pseudomyxoma peritonei

OPINION STATEMENT

Pseudomyxoma peritonei and peritoneal carcinomatosis derived from appendiceal epithelial tumors are controversial entities from classification to treatment. For the former entity, multiple classification systems have been attempted to distinguish indolent from more aggressive subtypes. The treatment of the low grade variants is managed with serial cytoreduction surgery, with data indicating possible, but unproven, benefit from heated intraperitoneal chemotherapy (HIPEC). There is no consensus on the role of cytoreduction and HIPEC for the management of the more aggressive histologic variants and peritoneal carcinomatosis. Currently, we believe systemic chemotherapy is the standard of care for patients with the high grade variants and peritoneal carcinomatosis.

Whole abdominopelvic radiotherapy in the palliative treatment of pseudomyxoma peritonei

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare clinical syndrome characterized by mucinous peritoneal disease arising from disseminated peritoneal adenomucinosis. Primary treatment involves a combination of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). There is no consensus on the proper treatment of recurrent PMP. In selected patients, repeated cytoreductive surgery with or without HIPEC might improve outcome. However, every repeated debulking procedure becomes less effective with increased morbidity.

CASE REPORT

We present a case of a patient with intestinal obstruction caused by recurrent pseudomyxoma peritonei. We treated the patient with whole abdominopelvic radiotherapy (WAPRT) using intensity-modulated arc therapy (IMAT) to a total dose of 33 Gy, delivered in 22 daily fractions. The treatment was well tolerated and resulted in resolution of the obstruction for a period of 24 months.

CONCLUSION

To the best of our knowledge, we present the first case report showing the possibility of resolving intestinal obstruction with WAPRT in a patient with recurrent PMP. It is our opinion that WAPRT delivered by IMAT, in analogy with ovarian cancer, should be considered as a palliative treatment option in managing patients with recurrent PMP especially in case of obstruction.

Complete cytoreduction for pseudomyxoma peritonei is optimal but maximal tumor debulking may be beneficial in patients in whom complete tumor removal cannot be achieved

BACKGROUND

Pseudomyxoma peritonei is a diffuse peritoneal malignancy that generally originates form a perforated appendiceal tumor. Optimal treatment requires extensive surgical resection to achieve complete cytoreduction combined with hyperthermic intraperitoneal chemotherapy. In a proportion of patients this is impossible, in particular, owing to extensive irresectable small-bowel involvement. There is ongoing debate as to the role of maximal tumor debulking in such cases.

OBJECTIVE

 : The aim of this study was to assess the outcomes of patients who underwent major tumor debulking for pseudomyxoma peritonei of appendiceal origin and to compare outcomes with patients who had complete cytoreduction during the same period.

DESIGN

This is a retrospective study.

SETTINGS

This investigation was conducted at a tertiary referral center for peritoneal surface malignancy.

PATIENTS

A prospective database of 953 consecutive patients with peritoneal malignancy undergoing surgery at a UK national referral center between 1994 and 2012 was analyzed. Of these patients, 748 (78%) had surgery for pseudomyxoma peritonei of appendiceal origin.

MAIN OUTCOME MEASURES

Survival, morbidity, and mortality in both groups were compared. Univariate and multivariate analyses were performed to identify negative prognostic factors in the group that underwent major tumor debulking.

RESULTS

Complete cytoreductive surgery was achieved in 543/748 (73%) patients, and 205 (27%) had maximal tumor debulking. Median age was 56 years (172 (31.7%) men) in the complete cytoreductive surgery group and 59 years (108 (52.7%) men) in the maximal tumor debulking group. Overall survival at 3, 5, and 10 years was 90%, 82%, and 64% in the complete cytoreductive group and 47%, 30%, and 22% in the maximal tumor debulking group. The median survival in the maximal tumor debulking group was 32.8 months (95% CI, 24.1-41.5).

LIMITATIONS

The retrospective analysis of prospective data was a limitation of this study.

CONCLUSIONS

Maximal tumor debulking may help patients with pseudomyxoma peritonei in whom complete cytoreduction cannot be achieved with almost half alive at 3 years with long-term survival in some.

Female patients with pseudomyxoma peritonei: a single-institution clinicopathologic study of 35 cases

PURPOSE

To explore clinicopathologic/prognostic aspects of pseudomyxoma peritonei (PMP).

METHODS

We reviewed records of 35 female patients with PMP treated at a single institution.

RESULTS

Patients' median age was 57.0 years (range 35.0-71.0 years). Their median pre-surgery level of carbohydrate antigen 19-9 (CA-199) was 80.95 U/ml (range 0.00-1,562.10 U/ml); of carbohydrate antigen 12-5 (CA-125), 44.00 U/ml (range 0.90-231.20 U/ml); and of carcinoembryonic antigen (CEA), 17.20 ng/ml (range 2.04-211.60 ng/ml). Of the 35 patients, 23 (65.7 %) underwent cytoreductive surgery (CRS) by gynecological oncologists and 12 (34.3 %) underwent non-CRS surgeries by general gynecologists or surgeons, including one patient who refused surgical treatment beyond a diagnostic laparoscopy. After surgery, 18 patients (51.4 %) had residual lesions, 11 (31.4 %) had complete lesion removal and 6 (17.1 %)had insufficient information on residual lesion; 21 (60.0 %) had appendiceal-based tumors and 12 (34.3 %) had ovarian-based tumors. Median follow-up time was 37 months (range 1-148 months), during which 28 patients (80.0 %) had relapsed. By the end of the study, 12 patients (34.3 %) died of PMP, 16 (45.7 %) survived with disease, and 7 (20 %) survived without disease. Median progress-free survival (PFS) was 12 months (range 0.5-114.0 months). Median overall survival time was 42 months (range 5-150 months). Ovarian tumor origin, post-surgery residual lesions, preoperative CA199 > 258.9 U/ml and CA125 > 70.6 U/ml were independent predictors of PFS.

CONCLUSIONS

PMP is rare in women, and has a poor long-term survival rate. Multi-center cooperation to gather more cases is needed to explore its behavior and proper treatment.