Histologic appearance of microcystic serous adenoma

(A) Microcystic serous adenoma of the pancreas. Numerous small spaces are lined by cuboidal epithelium. Hematoxylin and eosin-stained section.
(B) Periodic Acid Schiff (PAS) staining of serous pancreatic cystadenoma. Note positive staining (arrows) identifying glycogen-rich cells lining cystic spaces.