Idiopathic Myointimal Hyperplasia of the Mesenteric Veins: Diagnosed After Resection due to Insufficient Palliative Surgery

Gallbladder Mixed Neuroendocrine–Non-Neuroendocrine Neoplasm Consisting of Adenocarcinoma and Neuroendocrine Tumor G2 Diagnosed after Surgery for Acute Cholecystitis: A Case Report and Exome Analysis