Neuroendocrine carcinoma of pancreas

A rare neuroendocrine neoplasm of pancreas characterized by a high-grade malignant epithelial tumor with neuroendocrine differentiation. Based on histopathologic appearance, a small cell (composed of diffuse sheets of cells) and a large cell type (showing a nesting/trabecular pattern) are distinguished. Synaptophysin and chromogranin are positive on immunohistochemistry. The Ki-67 proliferation index is typically very high (>60 - 80%). Patients present with back pain, jaundice, and/or non-specific abdominal symptoms. Serum hormone activity is unusual. The tumor is highly aggressive with poor prognosis.