Abstract: Acinar cell cystadenoma (ACA), also referred to as “acinar cystic transformation”, is a rare and newly recognized cystic lesion of the pancreas. This cystic lesion displaying apparent acinar cell differentiation and lacking of distinct cellular atypia was accepted as the benign counterpart of acinar cystadenocarcinoma. However, the exact etiopathogenesis of ACA is still not clear.