Pseudomyxoma Peritonei: First-Line Management
The recommended first-line management for pseudomyxoma peritonei is complete cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC), which should be performed at a specialized center with substantial experience in peritoneal surface malignancies. 1, 2, 3
Definitive Treatment Approach
Primary Treatment Strategy
Complete cytoreductive surgery with HIPEC is the only curative treatment for PMP, with 5-year overall survival ranging from 62.5%-100% for low-grade disease and 0%-65% for high-grade disease. 2, 4
The surgical procedure typically requires approximately 10 hours and involves bilateral parietal and diaphragmatic peritonectomies, right hemicolectomy, radical greater omentectomy with splenectomy, cholecystectomy, liver capsulectomy, pelvic peritonectomy with or without rectosigmoid resection, and bilateral salpingo-oophorectomy with hysterectomy in females. 3
Treatment must be performed at specialized centers with multidisciplinary teams including surgical oncology with substantial CRS experience, medical oncology, radiology, pathology, and palliative care specialists. 1
Patient Selection Criteria
Preoperative staging with MDCT is essential, as radiological scores have demonstrated 94% sensitivity and 81% specificity in predicting resectability and survival. 2
Unlike other peritoneal malignancies, even very extensive disease with high Peritoneal Carcinomatosis Index (PCI) may still be amenable to complete excision and cure due to the slow disease progression characteristic of low-grade PMP. 3
Patients should undergo disease burden assessment using the Peritoneal Carcinomatosis Index to guide treatment decisions. 1, 5
Critical Distinguishing Features of PMP
Unique Disease Characteristics
PMP follows a "redistribution phenomenon" where mucinous tumor cells accumulate at specific sites due to gravity and peritoneal fluid absorption patterns, particularly affecting the greater and lesser omentum and the right hemidiaphragm, while relatively sparing the motile small bowel. 3
The disease typically originates from a ruptured low-grade mucinous neoplasm of the appendix, though the primary tumor may not always be identified at surgery. 3, 6
Low-grade PMP progresses slowly and may remain asymptomatic until advanced stages, which differs significantly from other peritoneal malignancies. 3
When Complete Resection Is Not Feasible
Maximum tumor debulking can still result in long-term survival in PMP, even when complete tumor removal is not achievable—a unique feature distinguishing it from other peritoneal surface malignancies. 3
This approach contrasts with colorectal peritoneal carcinomatosis, where incomplete cytoreduction offers minimal benefit. 1
Treatment-Related Outcomes and Complications
Treatment-related morbidity ranges from 12%-67.6%, with mortality rates of 0%-9%. 4
Major complications occur in up to 24% of cases, emphasizing the importance of appropriate patient selection and specialized center treatment. 2
Tumor marker elevations (such as CEA and CA 19-9) correlate with worse prognosis and increased recurrence rates, and should be obtained preoperatively for prognostic stratification. 2, 4
Common Pitfalls to Avoid
Do not treat PMP with systemic chemotherapy alone as first-line therapy—this is fundamentally different from gastric or colorectal peritoneal carcinomatosis where systemic therapy may be the primary treatment. 1, 3
Do not delay referral to a specialized center for preoperative staging and treatment planning, as optimal outcomes require experienced surgical teams. 1
Do not assume unresectability based solely on high PCI scores, as PMP's indolent biology allows for curative resection even with extensive disease burden. 3