Large cell neuroendocrine carcinoma of the ampulla of Vater with glandular differentiation.

Large cell neuroendocrine carcinoma of the ampulla of Vater is extremely rare. A 55 year old woman presented with an ampullary tumour causing pancreaticobiliary obstruction and a pancreaticoduodenectomy was performed. Microscopically, the tumour was diagnosed as a CD117 positive large cell neuroendocrine carcinoma with glandular differentiation. Four months later the patient developed a general recurrence. The metastatic tumours showed CD117 negativity and pure neuroendocrine features. The patient died of disease six months after diagnosis. It is postulated that the two components originated from a common multipotential stem cell. The clinical behaviour of ampullary large cell neuroendocrine carcinomas appears to be highly aggressive, with early metastases and a fatal outcome.