Figure 1.

Immunohistochemical staining of ampullary adenocarcinoma. (A) strong immunostaining for hENT1 in intestinal type carcinoma. (B) Details of (A). (C) Negative expression for hENT1 in pancreaticobiliary type carcinoma whereas adjacent lymphocytes (arrows) demonstrate staining and provide a positive internal control. (D) Details of (C). (E) Only distinctly Ki67 (MIB-1) immunoreactive tumour cell nuclei were valued as positive. (F) Strict criteria were used to define a cell as apoptotic: only positive TUNEL stained with the presence of a condensed and often fragmented nucleus together with a surrounding halo (arrowheads). Scale bars: A, C = 50 µm; B, D, E, F = 10 µm.