Beyond the Inflamed Appendix: Low-Grade Appendiceal Mucinous Neoplasm-Emphasis on Macroscopic Findings.

Area of Science:

• Gastroenterology
• Surgical Pathology
• Oncology

Background:

• Low-grade appendiceal mucinous neoplasms (LAMNs) are rare epithelial tumors.
• LAMNs often present with symptoms similar to acute appendicitis.
• Progression to pseudomyxoma peritonei can cause significant long-term morbidity.

Purpose of the Study:

• To report a case of LAMN with unexpected progression.
• To highlight the diagnostic challenges associated with LAMN.
• To emphasize the importance of gross examination and histological analysis in detecting peritoneal spread.

Main Methods:

• Case report of a 51-year-old male with periumbilical pain, nausea, and fever.
• Diagnostic workup included abdominal ultrasound and appendectomy.
• Histological examination and postoperative reoperation were performed.

Main Results:

• Clinical presentation suggested acute appendicitis, but ultrasound revealed cystic dilation of the appendix.
• Appendectomy showed a cystic, pearly appendix with mucinous exudate and extra-appendiceal spread.
• Postoperative reoperation confirmed pseudomyxoma peritonei.

Conclusions:

• LAMN poses a diagnostic challenge, often mimicking acute appendicitis.
• Meticulous gross examination and complete histological embedding are crucial for diagnosis.
• Subtle macroscopic findings can indicate significant peritoneal dissemination, necessitating prompt management.