What is the treatment for pseudomyxoma peritonei (PMP) limited to the omentum with mucin in the right lower quadrant in a 75-year-old patient?

Treatment for Pseudomyxoma Peritonei Limited to Omentum in a 75-Year-Old

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is the recommended treatment for pseudomyxoma peritonei (PMP) limited to the omentum with mucin in the right lower quadrant in a 75-year-old patient. 1

Disease Overview

• Pseudomyxoma peritonei is an uncommon condition characterized by mucinous ascites and implants on peritoneal surfaces and omentum, typically originating from a ruptured low-grade mucinous neoplasm of the appendix 1, 2
• The disease follows a "redistribution phenomenon" where mucinous tumor cells accumulate at specific sites due to gravity and at areas of peritoneal fluid absorption 1
• Despite its slow progression, PMP remains fatal if untreated as the abdominal cavity becomes filled with mucinous tumor 2

Surgical Management

• Complete macroscopic tumor excision through cytoreductive surgery is the cornerstone of treatment 1, 3
• For omental involvement, radical greater omentectomy is indicated as part of the surgical approach 1
• All involved omentum should be removed to achieve optimal cytoreduction 4
• Appendectomy should be performed in all mucinous tumors to address the likely primary site 4
• The surgical procedure may include:
  • Bilateral parietal and diaphragmatic peritonectomies 1
  • Right hemicolectomy if the appendix or adjacent structures are involved 1
  • Cholecystectomy and liver capsulectomy if indicated 1
  • Pelvic peritonectomy with or without rectosigmoid resection 1

Intraperitoneal Chemotherapy

• HIPEC should be administered immediately following complete cytoreduction 1, 5
• This combined approach (CRS+HIPEC) offers the best chance for long-term survival and potential cure 1
• Patients with low-volume residual disease after surgical cytoreduction should be considered for intraperitoneal therapy 4

Special Considerations for Elderly Patients

• Despite the patient's age (75 years), aggressive treatment should still be considered if the patient has good performance status 1
• A unique feature of low-grade PMP is that even extensive disease may be amenable to complete excision and cure 1
• In cases where complete tumor removal is not feasible due to age or comorbidities, maximum tumor debulking can still result in long-term survival 1

Preoperative Assessment

• Thorough preoperative assessment is essential to determine the extent of disease and the patient's fitness for extensive surgery 3
• CT scan of the chest, abdomen, and pelvis is the imaging modality of choice to evaluate disease extent 4
• Diagnostic laparoscopy may be considered to assess the feasibility of complete cytoreduction 4

Prognostic Factors

• The pathological classification (disseminated peritoneal adenomucinosis vs. peritoneal mucinous carcinomatosis) significantly impacts prognosis 6
• The Peritoneal Carcinomatosis Index (PCI) score helps quantify disease burden and predict outcomes 1
• Five-year survival rates range from 53% to 75%, with better outcomes in less aggressive histological subtypes 3

Follow-up Care

• Close monitoring is required following treatment to detect recurrence 3
• The majority of patients will eventually experience disease recurrence, necessitating long-term surveillance 3
• Repeat surgical debulking may be necessary for recurrent disease 5

In conclusion, despite the patient's advanced age, the limited disease distribution (omentum with mucin in right lower quadrant) makes the patient potentially suitable for curative treatment with CRS+HIPEC, which offers the best chance for long-term survival and disease control.