Supplementary Data SUPPLEMENTARY FIG. S1. Teratoma. The tumor is composed predominantly of keratinizing squamous epithelium (Sq), which forms cysts filled with keratin (arrows). The tumor also contains smooth muscle (Sm) tissue. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S2. Teratoma. Portion of a teratoma composed of neural tissue. The large cells in the central part correspond to ganglion cells. The cystic structures on the right side of the figure are lined by a nondescript flat epithelium. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S3. Teratoma. Portion of a teratoma composed of glial cell-rich neural tissue and small ganglion cells. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S4. Teratoma. Portion of the tumor composed of retinoblastic cells (R) and lentoids (L). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S5. Teratoma. The tumor contains a centrally located structure composed of immature retinal epithelium (R), some ducts (D), squamous cysts (Sq), and fat tissue (F). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S6. Teratoma. This tumor contains a centrally located retinoblastic tube (R), composed of hyperchromatic small blue cells with scant cytoplasm. On the left side, these cells differentiate into loosely arranged neural/retinal cells. On the upper part of this tube, there are pigmented cells (P). The tumor also contains immature neural cells arranged into a neural tube (NT). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S7. Teratoma. The tumor consists of neural tissue (N), NT (arrows), immature retinal tubes (R), and some pigmented cells (P). The centrally located duct (D) is lined by several types of epithelia, which are mostly cuboidal and columnar. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S8. Teratoma. Portion of a tumor composed of a retinoblastic tube (R) and thyroid follicles filled with colloid (T). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S9. Teratoma. The tumor contains several elongated ducts (D) lined by cuboidal or columnar epithelium. Smaller ducts are lined by a flat nondescript epithelium. In the right lower corner, the tumor consists of neural tissue (N). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S10. Teratoma. The tumor is composed predominantly of glands (G, arrows) and ciliated ducts (asterisk). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S11. Teratoma. The central part of this tumor contains glands resembling the acini of the pancreas (G) adjacent to a duct (D). There are also bundles of striated muscle (M), neural tissue (N), and NT (arrows). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S12. The tumor contains large amounts of bone with bone marrow cells and stroma (B), nests of cartilage (C), ducts (D), muscle (M), and fat tissue (F). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S13. Teratocarcinoma. Centrally located confluent nests of embryonal carcinoma (EC). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S14. Teratocarcinoma. Nests of EC (arrows) and mesenchymal tissue (M). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S15. Teratocarcinoma. Nests of EC surrounded by loose mesenchymal tissue. A nest of cartilage is seen in the right upper corner. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S16. Teratocarcinoma. Nests of EC (*) surrounded by dense mesenchymal ( Me) stroma. In the left upper corner, a neural medullary tube (M) with centrally located eosinophilic neural support cells has formed. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S17. Teratocarcinoma. NTs in early stages of development. The cells in the right lower corner above the scale bar are most likely EC cells, but without additional staining these cells cannot be positively identified. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S18. Teratocarcinoma. Nests of EC undergoing differentiation into embryonic mesenchyme (Me), and possibly into a NT (arrow). The section illustrates the similarities between the EC and early neural cells, which cannot be distinguished one from another with certainty. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S19. Teratocarcinoma. EC cells form a nest surrounded by mesenchymal cells, which are more loosely textured. A nest of EC shows prominent apoptosis. Apoptotic cells are also seen in the NT in the right lower corner as well. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S20. Teratocarcinoma. EC cells with apoptosis and an NT. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S21. Teratocarcinoma. EC may form compact nests, as seen on the left side of the figure, or appear more dispersed, forming broad sheets indistinctly separated from the mesenchymal cells, as seen on the right side of the figure. Apoptosis is the most prominent in the right upper corner. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S22. Teratocarcinoma. Two embryoid bodies (EBs) protrude into a cavity. The smaller EB (upper arrow) consists of a central mass of EC and an outer layer corresponding to the endoderm. The larger EB (side arrow) has an endodermal layer only on its top part. It forms a cavity with a few cells floating in it. There is ECmesenchymal transition (Me) in the right part of the EB. The surrounding stroma contain striated muscle cells ( M). Scale bar = 5 mm.
SUPPLEMENTARY FIG. S23. Higher power view of the EB shown in Supplementary Fig. S22. The solid central part of the EB is formed of EC cells, which are surrounded externally by a layer of cuboidal endoderm (arrow).
SUPPLEMENTARY FIG. S24. Teratocarcinoma. Floating EB vary in size and shape. The cavity of the largest EB is apparently subdivided into several smaller cavities. Scale bar = 5 mm.
SUPPLEMENTARY FIG. S25. Teratocarcinoma. Part of the tumor composed of yolk sac cells forming duct-like structures in a basement membrane-rich extracellular matrix. Scale bar = 5 mm.