Fig. 2

Microscopic findings: H&E sections at low (40×, a) and high (200×, b) magnification showed mucinous differentiation with major elements of solid and cribriform growth patterns. The immunohistochemical phenotype was characterised by positivity for CDX2 (c), and negativity for PAX8 (d). Correspondingly, the expression of CK20 (e) followed the CDX2 postive areas. However, CK7 (f) was also present. MLH1 staining (g) showed a protein loss, whereas MSH2 remained positive (h). Of note, stromal cells served as positive internal controls for MLH1 and MSH2 (g, h)