Rare Case of Low-Grade Appendiceal Mucinous Neoplasm with Acellular Serosal Mucin: A Case Report and Review of Literature

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare epithelial tumors of the appendix that can lead to pseudomyxoma peritonei (PMP) if mucin spills into the peritoneal cavity. We report a 65-year-old man who presented with right iliac fossa pain and an appendicular mass. Exploratory laparotomy revealed a dilated appendix with mucinous content and ~200 mL of acellular mucin. Histopathology confirmed a well-differentiated LAMN (Grade 1) with acellular mucin reaching the serosa (pT4a), no invasion, and negative margins. Postoperative recovery was uneventful, and follow- up PET-CT revealed no recurrence. Appendectomy with lavage and surveillance was deemed sufficient. Surgeons should consider LAMN in appendicular masses associated with mucinous collections.