Metastatic gastric adenocarcinoma and synchronous carcinoid tumour mimicking appendicitis: A case report

INTRODUCTION: Silent metastatic gastric adenocarcinoma presenting as appendicitis is very rare. Rare pathologies may be encountered during common operations such as appendicectomy and an awareness of possible alternative pathological entities would be helpful in a surgeon’s wealth of knowledge. PRESENTATION OF CASE: A 63-year-old man presented with a three-day history of acute abdominal pain suggestive of appendicitis. Intra-operatively, a macroscopically inflamed and perforated appendix was found. There were however some atypical features, which included multiple inflamed ulcerated lesions throughout the small bowel mesentery and along the terminal ileum. Appendicectomy was performed and biopsies of these lesions were taken. Subsequent histopathology revealed that there were metastatic deposits of poorly differentiated adenocarcinoma in the appendix and mesenteric biopsies, as well as a neuroendocrine (carcinoid) tumour of the appendix. Upper endoscopy confirmed a gastric primary leading to peritoneal dissemination. The patient was scheduled to undergo a course of palliative chemotherapy. DISCUSSION: Metastatic gastric adenocarcinomas with peritoneal dissemination have a very poor prognosis and often the first choice of treatment is chemotherapy as a complete cure through surgery is often not feasible. As for classical carcinoid tumours smaller than 2 cm towards the tip of the appendix with low proliferative index and without angiolymphatic or mesoappendiceal extension, then appendicectomy alone is indicated. Synchronous neoplastic pathologies presenting as appendicitis is largely unknown. CONCLUSION: To our knowledge, this is the first report in the literature of synchronous carcinoid tumour and metastatic gastric cancer co-existing within an inflamed appendix.