Fig. 3

Macroscopic and microscopic findings. a The cut surface of the excised solid-cystic mass showing light tan glistening tissue. The arrow indicates the tumor. b A lower power view shows that the tumor cells (asterisk) originated from the gastric wall and attached to the pancreatic parenchyma without invasion (hematoxylin and eosin staining; original magnification × 40). c Histopathological findings show uniform cord-like proliferation of spindle-shaped cells with minimal atypia, and the intercellular spaces are filled with thick bundles of collagen fibers (hematoxylin and eosin staining; original magnification × 100). d Immunohistochemically, the spindle cells are diffusely and strongly positive for nuclear β-catenin protein. (× 100)