E3428. The Mucinous Menace: A Radiologist's Guide to Pseudomyxoma Peritonei, Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.
  1. Anthony Cusano; University of British Columbia
  2. Lee Treanor; University of British Columbia
  3. Emily Pang; University of British Columbia
  4. Alison Harris; University of British Columbia
Pseudomyxoma peritonei (PMP), arising from dissemination of a mucinous tumour in the peritoneal cavity, poses a unique diagnostic and therapeutic challenge. Cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is a modern effective treatment for PMP. This exhibit aims to review the radiologist’s key role in detecting peritoneal metastatic disease, assessing for treatment complications of HIPEC and CRS, helping to manage these complications and monitoring for disease recurrence.

Educational Goals / Teaching Points
PMP is a rare neoplastic condition resulting from the peritoneal spread of a mucinous tumour. PMP distributes throughout the abdomen in a characteristic pathway with a role for dual energy CT in disease diagnosis. CRS with HIPEC improves long-term survival while limiting the effects of systemic chemotherapy. The radiologist must be aware of HIPEC surgery complications including abscess, fistula, perforated viscus, peritonitis, and pancreatic or bile leak. Surveillance imaging is needed for early detection of recurrence and recognition of delayed HIPEC complications.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
PMP is characterized by the macroscopic appearance of mucinous ascites originating from an intraabdominal malignancy, most commonly appendiceal, ovarian, or colonic. PMP classically distributes along the flow of ascitic fluid. The greatest volumes of mucin collect in the pelvis due to gravity. Negative thoracic pressure from breathing leads to the superior migration of mucin to collect near the inferior small bowel mesentery, undersurface of the diaphragm, right paracolic gutter, and greater and lesser omenta. The sites of bowel anchoring are another site of common mucin collection, including the rectosigmoid colon, ileocecal valve, and pylorus. The common imaging findings of PMP include ascites with scalloping of visceral surfaces, lobulated fluid collections, peritoneal deposits, omental caking and a primary mucinous tumor. Dual energy CT is a useful tool that can be used to maximize the conspicuity of peritoneal deposits.

The radiologist plays an essential role in the comprehensive care of patients with PMP. Understanding PMP's imaging characteristics, distribution in the abdomen, and complications of CRS with HIPEC is critical for accurate diagnosis. Furthermore, imaging surveillance is crucial for the early detection of PMP recurrence and the timely recognition of delayed HIPEC-related complications, facilitating improved patient outcomes.