Fig. 1.

Immunohistochemical correlates of somatic mutations in pancreatic neoplasms. (A) Mutation in TP53 causes strong diffuse nuclear expression of the protein. (B) SMAD4 mutation causes loss of protein expression in malignant glands, while expression is retained in non-neoplastic stromal and endothelial cells. (C) Undifferentiated carcinomas often lose E-cadherin expression. (D) Solid-pseudopapillary neoplasms show aberrant nuclear accumulation of β-catenin. The adjacent non-neoplastic pancreas shows normal membranous staining.