Although the immunohistochemical findings with CK-7, CK-20, CK-19, CA 19-9, CEA, MUC-1 and Ki-67 weren't explicit enough to differentiate the case, the presence of a transitional phase (from normal to dysplastic and to an in situ carcinoma) in the epithelium of the heterotopic pancreatic ducts leads to the conclusion that the carcinoma is a pancreatic one. The gene discussed is MUC1; the disease is in situ carcinoma.