Pseudomyxoma peritonei originating from intestinal duplication:A case report and review of the literature

BACKGROUND Pseudomyxoma peritonei(PMP)is a rare mucinous neoplasm with a relatively low incidence of 1 to 2 per million individuals.It is typically characterized by a type of gelatinous ascites named“jelly belly”.Most cases of PMP occur in association with ruptured primary mucinous tumors of the appendix(90%).Periodically,PMP can originate from mucinous carcinomas at other sites,including the colorectum,gallbladder,and pancreas.However,unusual origin can occur,as noted in this case report.CASE SUMMARY A 52-year-old woman had an unusual derivation of PMP from intestinal duplication.The patient complained of abdominal distension and increasing abdominal girth.Abdominal contrast-enhanced computed tomography showed a mass in the greater omentum located on the left side of the abdomen,likely to be a cystic mass of peritoneal origin.A PMP diagnosis was presumed based on the specific signs of the mass with flocculent and stripe-like echoes in ultrasound images.Ultrasound-guided percutaneous aspiration suggested a high likelihood of PMP.Once the PMP diagnosis was recognized,identification of the origin of the primary tumor was indicated.Thus,an exploratory laparoscopy was performed.In the absence of a primary tumor of appendix origin,the diagnosis of a low-grade mucinous neoplasm of intestinal duplication origin was finally confirmed by histopathology.CONCLUSION PMP is secondary to mucinous carcinomas of the appendix mostly.This case resulted from an unusual derivation from intestinal duplication.

Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Pseudomyxoma Peritonei of Appendiceal Origin-801 Cases from a Single Institution in China

Aim:As more and more centers has published their treatment results of pseudomyxoma peritonei(PMP)with cytoreductive surgery(CRS)and hyperthermic intraperitoneal chemotherapy(HIPEC),the data from China is missing.Myxoma Department of Aerospace Hospital is the biggest center treating PMP in China.The purpose of this study is to report the early and long-term outcomes for PMP from this single center.Methods:801 appendix-derived PMP out of 1008 consecutive patients treated in Myxoma Department of Aerospace Hospital between 2008 and 2019 were retrospectively analyzed.Results:Complete cytoreductive surgery(CCRS)was achieved in 240(30%)patients with median PCI of 14(1~39),and the rest had maximal tumor debulking(MTD),HIPEC was implemented in 96.3%of CCRS and 78.6%of MTD.The major morbidity(grade III/IV)was 11.4%and the 30-day operative mortality is 0.7%.The 5-and 10-year OS of CCRS was 76.9%and 64.1%,which is significantly higher than MTD(5-,10-year OS as 36.1%,27.1%;p<0.001).On the univariate analysis,all prognostic factors(gender,PSS,interval time,prior chemotherapy,prior HIPEC,Peritoneal Cancer Index(PCI),completeness of cytoreduction(CC),HIPEC,pathology,present of serous ascites)were found to be associated with overall survival except for age.On multivariate analysis,only PCI>20,MTD,high pathologic grade and without HIPEC were independent factors predicting poorer prognosis.Conclusions:CCRS+HIPEC can benefit PMP well with controllable risks.MTD+HIPEC may benefit PMP as well when CCRS cannot be achieved after fully asscessment by an experienced peritoneal maglignacy center,but the surgery should be performed as limited as possible.