Figure 3

A high-grade serous carcinoma arises from a serous borderline tumor. A. A low-magnification view shows a focal high-grade serous carcinoma developing from the papillae (square) in a background of a typical serous borderline tumor. B. A higher magnification demonstrates enlarged and atypical high-grade serous carcinoma cells that organize in a papillary architecture. C and D. Immunohistochemistry of p53 shows that high-grade serous carcinoma cells are diffusely positive for p53, a pattern consistent with a missense TP53 mutation while the adjacent epithelial cells from the background serous borderline tumor are only focally and weakly positive, a pattern consistent with a wild-type TP53 sequence.