Morphological and immunohistochemical features of a diffuse pneumatosis cystoides intestinalis case was described in an adult pig. Gas filled cysts were present in large and small intestinal serosa and the wall of cysts were immunopositive to podoplanin antibody indicating the cysts were actually gas filled lymph vessels. As a result, the present case report clearly demonstrated that cystic structures proved to be dilated lymphatic vessels.