Low-Grade Appendiceal Mucinous Neoplasm: A Case Highlighting Diagnostic and Management Considerations

Appendiceal mucoceles (AMs) are rare pathological entities characterized by the accumulation of mucin within the appendiceal lumen. They may arise from either non-neoplastic or neoplastic processes, including low-grade appendiceal mucinous neoplasms (LAMNs). Due to their variable clinical presentation and often incidental discovery, diagnosis can be challenging. We report the case of a 29-year-old female who presented with a 3-month history of constipation and intermittent abdominal pain. Physical examination revealed mild right lower quadrant tenderness without signs of peritonitis. Laboratory findings were unremarkable. Abdominal CT demonstrated a cystic, fluid-filled structure at the base of the appendix. Colonoscopy revealed a glossy, dome-shaped protrusion at the appendiceal orifice, consistent with a mucocele. The patient underwent an elective laparoscopic appendectomy. Histopathologic examination confirmed the diagnosis of LAMN. Her postoperative course was uneventful, and she remained asymptomatic on follow-up. This case illustrates the diagnostic complexity of appendiceal mucoceles, particularly in young adults, where the condition is uncommon. The combination of cross-sectional imaging and endoscopic evaluation was pivotal in establishing the diagnosis. Early surgical management was crucial to prevent rupture and the potential development of pseudomyxoma peritonei. Clinicians should maintain a high index of suspicion for AMs in patients with unexplained gastrointestinal symptoms and characteristic imaging findings. Prompt diagnosis and appropriate surgical intervention ensure favorable outcomes and prevent serious complications.