Well or poorly differentiated nonfunctioning neuroendocrine carcinoma of the pancreas: A single institution experience with 17 cases

Abstract Aim To evaluate the influence of distinguishing between well and poorly differentiated nonfunctioning neuroendocrine pancreatic carcinomas (PC). Method Six well differentiated and 11 poorly differentiated nonfunctioning neuroendocrine PC were retrospectively analyzed for differences and compared with 340 ductal PC. Results 1. There was no difference in pT categories between well differentiated and, poorly differentiated nonfunctioning neuroendocrine PC and ductal PC. 2. The rate of the pN1 category was lower in well differentiated lesions (20%) than in poorly differentiated lesions (66%) and in the ductal PC group (75%). 3. The outcome of patients with R0 resections was significantly better for well differentiated neuroendocrine PC with all patients alive than for poorly differentiated ones and for ductal PC (5-year survival rate 0% and 18%, respectively). 4. The outcome following R1/R2 resections for poorly differentiated neuroendocrine PC tended to be similar than for ductal PC (1-year survival rate 20% vs. 33%). 5. There was no difference in mean survival time (9 months) between poorly differentiated lesions and ductal PC after palliative procedures. Conclusions The better outcome of surgical treatment of nonfunctioning neuroendocrine PC vs. that of ductal PC was confined to well differentiated neuroendocrine lesions. For poorly differentiated lesions the outcome was as poor as for ductal PC. These results underscore the importance to distinguish between well and poorly differentiated nonfunctioning neuroendocrine PC.