Histology of zebrafish embryos transplanted with a human pancreatic tumour. Transversal sections of zebrafish embryos transplanted with a primary human pancreatic tumour show the presence of micrometastases in different tissues at 3 dpt in 5 day old zebrafish. (A) The transversal section is approximately 40 μm caudal to the anterior end of the liver. The liver is circled with a thin white line and contains many tumour cells and some micrometastases. The square in the liver contains several micrometastases, of which one is depicted in higher magnification in B (fluorescence), C (DIC) and D (overlay). The upper square shows tumour cells and micrometastases around the mesonephric tubule (msn. tubule) and the mesonephric duct (msn. duct). The enlargement of the square is shown in F and J (HE staining). In both, F (white arrow) and J (black arrow) micrometastasis is indicated (high magnifications in G and H). In (E) HE staining of a transversal section approximately 24 μm rostral to the anterior start of the liver is shown and overlayed with the fluorescent image. A larger cell mass is indicated by an arrow. The same cell mass is indicated in I in which also a liver metastasis is seen. The cell mass is shown in high magnification in K (fluorescent picture) and in L (HE staining). Scales shown are A and E 1 mm, B-D, F-H and J-L 10 μm and in I: 500 μm.