Appendiceal Neuroendocrine Tumor Mimicking Acute Appendicitis

Area of Science:

• Gastroenterology and Oncology
• Pathology

Background:

• Appendiceal carcinoids represent the most common tumors of the appendix, accounting for 32-57% of all appendiceal neoplasms.
• Neuroendocrine tumors are a significant category within appendiceal neoplasms.

Observation:

• A case presented with symptoms mimicking acute appendicitis.
• Gross examination revealed appendiceal tip perforation with a 30 ml periappendicular collection.
• Histopathological analysis identified a carcinoid tumor infiltrating the muscularis propria and subserosa.

Findings:

• Tumor cells were arranged in tubules, acini, and nests.
• Immunohistochemistry confirmed the diagnosis with positive Synaptophysin staining.
• A Ki-67 labeling index of 2% indicated low proliferative activity.
• Absence of perineural and vascular invasion was noted.

Implications:

• This case underscores the importance of considering appendiceal neuroendocrine tumors in the differential diagnosis of acute appendicitis.
• Accurate diagnosis through histopathology and immunohistochemistry is crucial for appropriate patient management.
• Understanding the presentation and characteristics of appendiceal carcinoids aids in clinical decision-making.