Two cases of papillary and cystic neoplasm of the pancreas (PCN) occurring in 17 and 21 year old women are reported with ultrastructural and immunohistochemical findings. A review of the English literature shows that although potentially malignant, PCN, which occurs mainly in young women, is amenable to surgical cure. The significance of large PAS positive and alpha-1-antitrypsin positive tumour granules; the lack of specificity of alpha-1-antitrypsin for pancreatic acinar cells; the possibility of acinar differentiation of PCN; and its separation from pancreaticoblastoma are discussed.