Pseudomyxoma peritonei, characterised by progressive accumulation of gelatinous ascites and peritoneal implants, arises most commonly from which primary site?

• A Low-grade appendiceal mucinous neoplasm ✓
• B Serous cystadenoma of the ovary
• C Mucinous cystic neoplasm of the pancreas
• D Diffuse type gastric adenocarcinoma

Explanation

The overwhelming majority of pseudomyxoma peritonei cases arise from a mucinous neoplasm of the appendix, usually a low-grade appendiceal mucinous neoplasm that ruptures and disseminates mucus-secreting cells throughout the peritoneal cavity. Although ovarian mucinous tumours were historically implicated, immunohistochemistry (CK20, CDX2 positivity) confirmed the appendix as the primary in most cases previously attributed to the ovary. Pancreatic and gastric primaries cause mucinous ascites far less often.

Reference: Schwartz's Principles of Surgery, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.