When and When Not to Perform a Right Colon Resection with Mucinous Appendiceal Neoplasms

Area of Science:

• Gastroenterology
• Surgical Oncology
• Oncology

Background:

• Mucinous appendiceal neoplasms (MAN) with peritoneal dissemination are typically treated with cytoreductive surgery and hyperthermic perioperative chemotherapy.
• Standard surgical resection for MAN generally excludes the right colon and ileocolic lymph nodes.

Purpose of the Study:

• To assess the incidence of lymph node invasion in patients with peritoneal mucinous carcinoma (PMCA).
• To determine if right colectomy is indicated for specific grades of PMCA based on lymph node involvement.

Main Methods:

• A prospectively maintained database of patients with PMCA who underwent complete cytoreductive surgery was reviewed.
• Histologic grade of PMCA was correlated with lymph node invasion in the appendiceal mesentery and ileocolic group.
• Recurrence in ileocolic lymph nodes was monitored via CT scans or second-look surgery in node-negative patients.

Main Results:

• Of 299 PMCA patients, lymph node positivity was 6.8% for well-differentiated, 5.6% for moderately differentiated, and 29% for poorly differentiated tumors.
• No recurrence in ileocolic lymph nodes was observed in 151 patients with well- or moderately differentiated PMCA.

Conclusions:

• Low-grade PMCA has a low incidence of lymph node positivity (6.0%).
• High-grade PMCA demonstrates a significantly increased rate of lymph node invasion (29.0%).
• Right colectomy is recommended for patients with high-grade PMCA due to increased lymph node metastasis risk.