In such situations, EUS, EUS-FNA, EUS-TTNB can be helpful diagnostic tools: cytology, cyst fluid analyses of carcinoembryonic antigen (CEA), amylase and molecular biomarkers as well as cyst wall biopsy, allow distinction of mucinous vs non-mucinous cystic neoplasms and permit identification of the specific histological types [9, 63]. Here, CEACAM5 is linked to cyst.