All patients exhibited normal serum levels of tumor markers, including α-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), cancer antigen 125 (CA-125), and carcinoembryonic antigen (CEA).Of the 51 patients, catecholamine and vasoactive intestinal peptide testing was performed in 13, all of whom had negative results.All 51 patients underwent contrast-enhanced computed tomography (CT), with six (11.8%, 6/51) receiving supplemental contrast-enhanced magnetic resonance imaging (MRI). Here, VIP is linked to neoplasm.