Evaluation of Risk Factors for Distant and Lymph Node Metastasis of Pancreatic Neuroendocrine Tumors.

Distant metastases are more often found in larger, distally located pNETs grade G2 and G3, while a higher occurrence of lymph node metastases seems to be associated only with larger tumor size. A considerable number of tumors <2 cm in size have distant metastases already at the diagnosis, which might indicate the need for careful qualification of smaller lesions for observation.