GNAS and metastatic malignant neoplasm in the lymph nodes: Among the malignant-potential IPMN dissected regions, GNAS mutation was less frequent among those with perivascular invasion compared to those without (0% vs. 63%, p = 0.0128), dissected regions with perineural invasion (0% vs. 58%; p = 0.0377), or dissected regions exhibiting lymph node metastasis (0% vs. 58%; p = 0.0377).