Peri-ampullary collision tumor - high grade neuroendocrine carcinoma and signet ring cell carcinoma: A case report and review of literature

We report a case of 50-year-old male with obstructive jaundice diagnosed as peri-ampullary collision tumor comprising of large cell neuroendocrine carcinoma and signet ring cell carcinoma. The association of neuroendocrine (usually carcinoids) and adenocarcinoma is extremely uncommon with only few case reports available in the reported literature.