A Case of Tubular Carcinoid of the Appendix: A Rare Entity

Abstract

Carcinoid tumours of the appendix are low-grade neoplasms with neuroendocrine differentiation. They are typically found incidentally during appendectomies. Tubular carcinoid is an extremely rare, distinct, and benign form of appendiceal carcinoid. Here, we present the case of a 32-year-old male who presented with an abdominal mass and pain radiating to the right iliac fossa. Appendectomy was performed, and the gross examination revealed a congested and exudate-covered appendix. Microscopic analysis showed small tubules infiltrating the appendix wall, along with evidence of acute appendicitis. Differential diagnoses considered included carcinoid tumour with glandular differentiation and metastatic adenocarcinoma. Additional sections were examined, and a final diagnosis of tubular carcinoid was made after conducting a panel of immunohistochemical markers and Alcian blue stain. Since most tubular carcinoids are not identifiable on gross, microscopic assessment and serial sectioning play a crucial role in diagnosing this condition.