Information for Doctors

Pseudomyxoma peritonei (PMP) is a rare illness with an incidence rate of around 2 persons per million. It is a diagnosis you may only give to one or two patients throughout your career, if at all. It is often difficult to differentiate between PMP and other more common types of mucinous tumour such as ovarian cancer without a thorough histological examination by an experienced pathologist.

Pseudomyxoma is a widely disseminated mucinous neoplasia occurring in the peritoneal cavity, and usually arises from a ruptured appendiceal tumour. It may present as a generalised accumulation of mucin in the abdominal cavity which often causes a distended abdomen, colloquially termed “jelly belly”. The accumulation of fluid becomes a problem for the patient as the pressure from the increasing amount of mucin begins to compress the internal organs, causing intestinal obstruction and pain. Other presentations may include enlarged ovaries in women or a new onset hernia.

Most cases of PMP are slow-growing, and patients generally experience a gradual increase in mucin accumulation over many years. You may find that some patients become symptomatic quite suddenly possibly as a result of intestinal obstruction or, in women, with the development of mucinous ovarian cysts or Krukenberg tumours which can grow rapidly in the space of a few months.

Differential diagnoses to consider include primary mucinous tumours of the colon, pancreas, gall bladder or ovary, and peritoneal mesothelioma. An experienced pathologist will be key to assisting you with obtaining a definitive diagnosis. An important point to note is that true PMP rarely originates in the ovary. Most cases of PMP with a large ovarian “cystadenoma” are found to have a clinically occult appendiceal primary.

Diagnosis of PMP is often first suspected through the use of abdominal imaging which demonstrates features such as mucinous ascites, omental cake and enlarged ovaries. Scalloping of the liver and splenic surfaces is a characteristic finding on CT. Primary tumours of the appendix may also be seen in these images, although this is not always the case. The most common appearance is that of an appendiceal mucocele. Sometimes, PMP is diagnosed during surgical interventions for other conditions.

Definitive diagnosis requires histopathological assessment of the appendiceal primary and the peritoneal disease. The most common lesion found in the appendix is a low grade appendiceal mucinous neoplasm (LAMN). Other possible appendiceal primaries include mucinous adenocarcinoma and the rare high grade appendiceal mucinous neoplasm (HAMN).The PMP is classified pathologically into three major categories: low grade mucinous carcinoma peritonei (previously known as disseminated peritoneal adenomucinosis), high grade mucinous carcinoma peritonei and high grade mucinous carcinoma peritonei with signet ring cells. The category of the disease may affect the treatment given to the patient, so consultation with an experienced pathologist is key to providing the best treatment.

Once diagnosed, the patient may either be treated radically with cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC), or else palliative debulking may be offered to manage symptoms. Sometimes, a wait-and-see approach, where the patient is monitored closely for progression of the disease, is most appropriate. Since it is often a very slow-growing cancer, patients who are frail or have other problems with their health may have a better chance of maintaining their quality of life without surgical intervention.

CRS is an extensive and invasive procedure, but is usually well-tolerated when performed in an experienced centre. The aim is to remove all visible tumour from the abdominal cavity. In addition to stripping peritoneum from the abdominal wall and hemidiaphragms, CRS can include colectomy, splenectomy, omentectomy and cholecystectomy, and, in females, hysterectomy and bilateral salpingo-oophorectomy. CRS is usually combined with hyperthermic intraperitoneal chemotherapy (HIPEC), which involves instilling heated chemotherapy solution into the peritoneal cavity to eliminate any residual circulating tumour cells reducing the risk of recurrence.

Pseudomyxoma peritonei is a “seeding” type cancer, and so extra care must be taken with PMP patients during surgery. If you come across a mucinous tumour or unexpected ascites in a patient during surgery, it is important to consider PMP. You may wish to check the appendix for involvement, and if you locate a tumour there, it is wise to consult with an abdominal cancer specialist immediately. Most importantly, avoid opening more surgical planes if possible. The opening of surgical planes leaves new, uninvolved tissue layers open to potential infiltration by shed PMP tumour cells, making it more difficult for PMP specialist surgeons to provide curative treatment to the patient later.

If you require more detailed information about pseudomyxoma peritonei, a list of consultant surgeons, pathologists and researchers who are willing to assist you in locating information in your country can be found by contacting the EuroPMP representative for your area.

Mercier F, Jeremie G, Alyami M, Delphine V, Vahan K, Pascal R, Sylvie I, Guillaume P, Olivier G. Long-term results of laparoscopic cytoreductive surgery and HIPEC for the curative treatment of low-grade pseudomyxoma peritonei and multicystic mesothelioma. Surg Endosc. 2019 Dec 2. doi: 10.1007/s00464-019-07280-1. [Epub ahead of print] PubMed PMID: 31792692.

Houlzé-Laroye C, Eveno C. Low-grade appendiceal mucinous neoplasms with bowel obstruction. Pleura Peritoneum. 2019 Oct 1;4(3):20190020. doi: 10.1515/pp-2019-0020. eCollection 2019 Sep 1. PubMed PMID: 31667332; PubMed Central PMCID: PMC6812216.

Al-Azzawi M, Misdraji J, van Velthuysen MF, Shia J, Taggart MW, Yantiss RK, Svrcek M, Carr N. Acellular mucin in pseudomyxoma peritonei of appendiceal origin: what is adequate sampling for histopathology? J Clin Pathol. 2019 Oct 13. pii: jclinpath-2019-206213. doi: 10.1136/jclinpath-2019-206213. [Epub ahead of print] PubMed PMID: 31611287.

Sørensen O, Andersen AM, Larsen SG, Giercksky KE, Flatmark K. Intraperitoneal mitomycin C improves survival compared to cytoreductive surgery alone in an experimental model of high-grade pseudomyxoma peritonei. Clin Exp Metastasis. 2019 Dec;36(6):511-518. doi: 10.1007/s10585-019-09991-0. Epub 2019 Sep 20. PubMed PMID: 31541325. PubMed Central PMCID: PMC6834750.

Solomon D, Bekhor E, Leigh N, Maniar YM, Totin L, Hofstedt M, Aycart SN, Carr J, Ballentine S, Magge DR, Golas BJ, Pai RK, Polydorides AD, Bartlett DL, Labow DM, Choudry HA, Sarpel U. Surveillance of Low-Grade Appendiceal Mucinous Neoplasms With Peritoneal Metastases After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Are 5 Years Enough? A Multisite Experience. Ann Surg Oncol. 2019 Aug 5. doi: 10.1245/s10434-019-07678-0. [Epub ahead of print] Erratum in: Ann Surg Oncol. 2019 Aug 19; PubMed PMID: 31385130.

Kusamura S, Azmi N, Fumagalli L, Baratti D, Guaglio M, Cavalleri A, Garrone G, Battaglia L, Barretta F, Deraco M. Phase II randomized study on tissue distribution and pharmacokinetics of cisplatin according to different levels of intra-abdominal pressure (IAP) during HIPEC (NCT02949791). Eur J Surg Oncol. 2019 Jun 21. pii: S0748-7983(19)30516-5. doi: 10.1016/j.ejso.2019.06.022. [Epub ahead of print] Review. PubMed PMID: 31262599.

Bartoş A, Bartoş D, Raluca S, Mitre C, Hadade A, Iancu I, Cioltean C, Iancu C, Militaru C, Părău A, Breazu C. Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for the Treatment of Peritoneal Carcinomatosis: Our Initial Experience. Chirurgia (Bucur). 2019 Mar-Apr;114(2):222-233. doi: 10.21614/chirurgia.114.2.222. PubMed PMID: 31060655.

Raimondi A, Corallo S, Niger M, Antista M, Randon G, Morano F, Milione M, Kusamura S, Baratti D, Guaglio M, Cremolini C, Marmorino F, Di Bartolomeo M, Deraco M, De Braud F, Pietrantonio F. Metronomic Capecitabine With Cyclophosphamide Regimen in Unresectable or Relapsed Pseudomyxoma Peritonei. Clin Colorectal Cancer. 2019 Jun;18(2):e179-e190. doi: 10.1016/j.clcc.2019.03.002. Epub 2019 Apr 1. PubMed PMID: 31023524.

Mercier F, Dagbert F, Pocard M, Goéré D, Quenet F, Wernert R, Dumont F, Brigand C, Passot G, Glehen O; RENAPE Network. Recurrence of pseudomyxoma peritonei after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. BJS Open. 2018 Sep 27;3(2):195-202. doi: 10.1002/bjs5.97. eCollection 2019 Apr. PubMed PMID: 30957067; PubMed Central PMCID: PMC6433307.

Lurvink RJ, Villeneuve L, Govaerts K, de Hingh IHJT, Moran BJ, Deraco M, Van der Speeten K, Glehen O, Kepenekian V, Kusamura S; List of PSOGI collaborators. The Delphi and GRADE methodology used in the PSOGI 2018 consensus statement on Pseudomyxoma Peritonei and Peritoneal Mesothelioma. Eur J Surg Oncol. 2019 Mar 23. pii: S0748-7983(19)30337-3. doi: 10.1016/j.ejso.2019.03.012. [Epub ahead of print] Review. PubMed PMID: 30954350.

Swain DR, Yates AL, Mohamed F, Dayal SP, Tzivanakis A, Cecil TD, Moran BJ. Do patients undergoing cytoreductive surgery and HIPEC for peritoneal malignancy need parenteral nutrition? Pleura Peritoneum. 2018 Oct 2;3(4):20180123. doi: 10.1515/pp-2018-0123. eCollection 2018 Dec 1. PubMed PMID: 30911667; PubMed Central PMCID: PMC6404997.

Barral M, El Sanharawi I, Eveno C, Dohan A, Launay JM, Lo Dico R, Pocard M, Bonnin P. Post-operative wall shear stress in the superior mesenteric artery: Biomarker of long term outcome in patients with residual disease after incomplete cytoreductive surgery for pseudomyxoma peritonei. Eur J Surg Oncol. 2019 Sep;45(9):1727-1733. doi: 10.1016/j.ejso.2019.03.001. Epub 2019 Mar 6. PubMed PMID: 30871885.

Dohan A, Bouquot M, Rousset P, Eveno C. ASO Author Reflections: Proposal of a New Preoperative Score to Predict Resectability in Pseudomyxoma Peritonei. Ann Surg Oncol. 2018 Dec 12. doi: 10.1245/s10434-018-7012-6. [Epub ahead of print] PubMed PMID: 30542837.

Kurtz F, Struller F, Horvath P, Solass W, Bösmüller H, Königsrainer A, Reymond MA. Feasibility, Safety, and Efficacy of Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) for Peritoneal Metastasis: A Registry Study. Gastroenterol Res Pract. 2018 Oct 24;2018:2743985. doi: 10.1155/2018/2743985. eCollection 2018. PubMed PMID: 30473706; PubMed Central PMCID: PMC6220392.

Thorgersen EB, Melum E, Folseraas T, Larsen SG, Line PD. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei in a liver-transplanted patient: a case report. World J Surg Oncol. 2018 Sep 5;16(1):180. doi: 10.1186/s12957-018-1482-7. PubMed PMID: 30185175; PubMed Central PMCID: PMC6126040.

Galan A, Rousset P, Mercier F, Képénékian V, Valette PJ, Glehen O, Passot G. Overall survival of pseudomyxoma peritonei and peritoneal mesothelioma patients after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy can be predicted by computed tomography quantified sarcopenia. Eur J Surg Oncol. 2018 Nov;44(11):1818-1823. doi: 10.1016/j.ejso.2018.07.060. Epub 2018 Aug 11. PubMed PMID: 30143249.

Saarinen L, Nummela P, Leinonen H, Heiskanen A, Thiel A, Haglund C, Lepistö A, Satomaa T, Hautaniemi S, Ristimäki A. Glycomic Profiling Highlights Increased Fucosylation in Pseudomyxoma Peritonei. Mol Cell Proteomics. 2018 Nov;17(11):2107-2118. doi: 10.1074/mcp.RA118.000615. Epub 2018 Aug 2. PubMed PMID: 30072579; PubMed Central PMCID: PMC6210226.

Nizri E, Kusamura S, Fallabrino G, Guaglio M, Baratti D, Deraco M. Dose-Dependent Effect of Red Blood Cells Transfusion on Perioperative and Long-Term Outcomes in Peritoneal Surface Malignancies Treated with Cytoreduction and HIPEC. Ann Surg Oncol. 2018 Oct;25(11):3264-3270. doi: 10.1245/s10434-018-6630-3. Epub 2018 Jul 26. PubMed PMID: 30051371.

Govaerts K, Chandrakumaran K, Carr NJ, Cecil TD, Dayal S, Mohamed F, Thrower A, Moran BJ. Single centre guidelines for radiological follow-up based on 775 patients treated by cytoreductive surgery and HIPEC for appendiceal pseudomyxoma peritonei. Eur J Surg Oncol. 2018 Sep;44(9):1371-1377. doi: 10.1016/j.ejso.2018.06.023. Epub 2018 Jul 6. PubMed PMID: 30017331.

Arjona-Sánchez Á, Rodríguez-Ortiz L, Rufián-Peña S, Sánchez-Hidalgo JM, Briceño-Delgado J. Laparoscopic approach in complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy by CO(2) closed system in a low grade pseudomyxoma peritonei. Cir Esp. 2018 Dec;96(10):656-658. doi: 10.1016/j.ciresp.2018.03.013. Epub 2018 Jun 22. English, Spanish. PubMed PMID: 29937297.

Pengelly RJ, Rowaiye B, Pickard K, Moran B, Dayal S, Tapper W, Mirnezami A, Cecil T, Mohamed F, Carr N, Ennis S. Analysis of Mutation and Loss of Heterozygosity by Whole-Exome Sequencing Yields Insights into Pseudomyxoma Peritonei. J Mol Diagn. 2018 Sep;20(5):635-642. doi: 10.1016/j.jmoldx.2018.05.002. Epub 2018 Jun 22. PubMed PMID: 29936255.

Arjona-Sanchez A, Rufian-Peña S, Sanchez-Hidalgo JM, Casado-Adam A, Cosano-Alvarez A, Briceño-Delgado J. Cytoreductive Surgery and Intraperitoneal Hyperthermic Chemotherapy (HIPEC) by Minimally Invasive Approach, an Initial Experience. World J Surg. 2018 Oct;42(10):3120-3124. doi: 10.1007/s00268-018-4634-6. PubMed PMID: 29691625.

Bignell MB, Mehta AM, Alves S, Chandrakumaran K, Dayal SP, Mohamed F, Cecil TD, Moran BJ. Impact of ovarian metastases on survival in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal malignancy originating from appendiceal and colorectal cancer. Colorectal Dis. 2018 Aug;20(8):704-710. doi: 10.1111/codi.14057. PubMed PMID: 29502336.

Delhorme JB, Severac F, Averous G, Glehen O, Passot G, Bakrin N, Marchal F, Pocard M, Lo Dico R, Eveno C, Carrere S, Sgarbura O, Quenet F, Ferron G, Goéré D, Brigand C; French National Network of Peritoneal Surface Malignancies (RENAPE). Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei of appendicular and extra-appendicular origin. Br J Surg. 2018 May;105(6):668-676. doi: 10.1002/bjs.10716. Epub 2018 Feb 7. PubMed PMID: 29412465.

Guaglio M, Sinukumar S, Kusamura S, Milione M, Pietrantonio F, Battaglia L, Guadagni S, Baratti D, Deraco M. Clinical Surveillance After Macroscopically Complete Surgery for Low-Grade Appendiceal Mucinous Neoplasms (LAMN) with or Without Limited Peritoneal Spread: Long-Term Results in a Prospective Series. Ann Surg Oncol. 2018 Apr;25(4):878-884. doi: 10.1245/s10434-017-6305-5. Epub 2017 Dec 21. Erratum in: Ann Surg Oncol. 2018 Jan 19;:. PubMed PMID: 29270877.

Mercier F, Passot G, Villeneuve L, Levine EA, Yonemura Y, Goéré D, Sugarbaker PH, Marolho C, Bartlett DL, Glehen O; BIG-RENAPE Working Group. Peritoneal Carcinomatosis of Urachus Origin Treated by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An International Registry of 36 Patients. Ann Surg Oncol. 2018 Apr;25(4):1094-1100. doi: 10.1245/s10434-017-6299-z. Epub 2017 Dec 13. PubMed PMID: 29238881.

Bouquot M, Dohan A, Gayat E, Barat M, Glehen O, Pocard M, Rousset P, Eveno C. Prediction of Resectability in Pseudomyxoma Peritonei with a New CT Score. Ann Surg Oncol. 2018 Mar;25(3):694-701. doi: 10.1245/s10434-017-6275-7. Epub 2017 Nov 30. PubMed PMID: 29192372.

Baratti D, Kusamura S, Milione M, Bruno F, Guaglio M, Deraco M. Validation of the Recent PSOGI Pathological Classification of Pseudomyxoma Peritonei in a Single-Center Series of 265 Patients Treated by Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy. Ann Surg Oncol. 2018 Feb;25(2):404-413. doi: 10.1245/s10434-017-6252-1. Epub 2017 Nov 20. PubMed PMID: 29159742.

Rangarajan K, Chandrakumaran K, Dayal S, Mohamed F, Moran BJ, Cecil TD. The pre-operative neutrophil-lymphocyte ratio predicts overall and disease-free survival following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with pseudomxyoma peritonei of appendiceal origin. Int J Hyperthermia. 2018 Aug;34(5):559-563. doi: 10.1080/02656736.2017.1384073. Epub 2017 Oct 24. PubMed PMID: 29063804.