[A Case of High‒Grade Appendiceal Mucinous Neoplasm Undergoing Ileocecal Resection]

Area of Science:

• Gastroenterology
• Surgical Oncology
• Radiology

Background:

• Appendiceal mucinous neoplasms are rare tumors.
• Misdiagnosis can occur due to overlapping symptoms with appendicitis.
• Peritoneal pseudomyxoma is a rare complication of mucinous neoplasms.

Purpose of the Study:

• To report a rare case of high-grade appendiceal mucinous neoplasm (HAMN) with peritoneal pseudomyxoma.
• To discuss the diagnostic challenges and successful management of this rare condition.
• To review the literature on appendiceal mucinous neoplasms.

Main Methods:

• A 75-year-old male presented with abdominal pain and fever.
• Initial diagnosis of abscess-forming appendicitis by contrast-enhanced computed tomography (CT).
• CT-guided drainage, followed by contrast-enhanced CT and MRI, led to revised diagnosis of appendiceal mucinous neoplasm and peritoneal pseudomyxoma.
• Surgical management included ileocecal resection.

Main Results:

• Initial CT-guided drainage did not reveal an abscess.
• Post-imaging revealed appendiceal mucinous neoplasm and peritoneal pseudomyxoma.
• Intraoperative findings included mucus deposits.
• Cytological examination of mucus showed no malignant findings.
• Pathological diagnosis confirmed high-grade appendiceal mucinous neoplasm (HAMN).
• The patient had an uneventful recovery and remained recurrence-free at 12 months.

Conclusions:

• High-grade appendiceal mucinous neoplasm (HAMN) can mimic appendicitis.
• Advanced imaging (CT, MRI) is crucial for accurate diagnosis.
• Surgical resection is an effective treatment for HAMN with peritoneal pseudomyxoma.
• This case underscores the importance of considering rare appendiceal neoplasms in the differential diagnosis.