Low-grade Mucinous Appendiceal Neoplasm: a Tumor in Disguise of Appendicitis

Area of Science:

• Gastroenterology and Oncology
• Surgical Pathology

Background:

• Appendiceal mucinous neoplasms (AMNs) represent a rare but significant malignant entity.
• Diagnostic imaging like ultrasonography and CT scans are valuable, yet diagnosis is frequently incidental or intraoperative.
• AMNs are often misdiagnosed as acute appendicitis, adnexal masses, or retroperitoneal tumors.

Observation:

• This case highlights the necessity of maintaining a high index of suspicion for appendiceal malignancy and mucocele rupture in patients undergoing appendectomy.
• A 65-year-old female with a history of bilateral adnexal surgery presented with a low-grade appendiceal mucinous neoplasm.
• Concurrent secondary malignancies, particularly in the ovaries, breast, kidneys, and gastrointestinal tract, occur in approximately 30% of AMN patients.

Findings:

• Low-grade appendiceal mucinous neoplasm demonstrates an excellent prognosis following standard appendectomy.
• Advanced-stage low-grade AMNs with periappendiceal involvement or nodal metastasis necessitate appendectomy with right hemicolectomy and lymph node dissection.

Implications:

• Emphasizes the importance of considering appendiceal malignancy in differential diagnoses, especially when appendicitis is suspected.
• Highlights the need for vigilance regarding synchronous malignancies in patients diagnosed with appendiceal mucinous neoplasms.
• Underscores the tailored surgical approaches required for different stages of appendiceal mucinous neoplasms to ensure optimal patient outcomes.