NCIt definition : An aggressive, high-grade, and poorly differentiated carcinoma with neuroendocrine
differentiation that arises from the gastroesophageal junction. The mitotic count
is more than 20 per 10 HPF. It is classified as either small or large cell neuroendocrine
carcinoma based on the size of the malignant cells, the prominence of the nucleoli,
and the amount of cytoplasm.;