Case Report: Acute Appendicitis as Initial Presentation of an Appendiceal Neuroendocrine Tumor

Introduction: Acute appendicitis remains the most common cause of acute surgical abdomen worldwide. While typically regarded as an inflammatory condition, routine pathological analysis can reveal unexpected findings, including appendiceal neoplasms. Neuroendocrine tumors (NETs) of the appendix, though rare, represent the second most common gastrointestinal tumor in pediatric patients and the most frequent appendiceal neoplasm. Case Presentation: We present the case of a 10-year-old male with clinical signs of acute appendicitis, confirmed by ultrasound and laboratory findings. Laparoscopic appendectomy was performed, and the specimen was submitted for pathological examination. Histopathological analysis revealed a well-differentiated grade 2 neuroendocrine tumor with infiltration into the internal muscular layer. Immunohistochemistry demonstrated diffuse chromogranin and synaptophysin positivity, with a Ki-67 index of less than 2%. Given the absence of metastasis or high-risk features, no further surgical or oncological intervention was required beyond regular follow-up. Discussion: Appendiceal NETs are frequently discovered incidentally in appendectomy specimens performed for suspected acute appendicitis. Despite their rarity, they necessitate careful histopathological evaluation to determine tumor grade, depth of invasion, and proliferative index, which guide management. In pediatric patients, most cases are managed conservatively with appendectomy alone, given their favorable prognosis. Conclusion: This case underscores the importance of routine histopathological examination of appendectomy specimens, as unsuspected neuroendocrine tumors may be discovered. Early detection and classification are crucial for appropriate management and long-term surveillance, ensuring optimal patient outcomes.