Fig. 2

Muscovy duck (case 2) with a metastasising teratocarcinoma. a X-ray of the duck with a coelomic mass (arrows) compressing internal organs. b Coelomic mass (10 × 12 × 3 cm) with coarse nodular surface. c Epithelial proliferation with squamous differentiation and keratin pearls (H) and epithelial nests (arrows). H&E. Bar: 200 μm. d Formation of cartilage (C) and bone tissue (B). H&E. Bar: 200 μm. e Small intestine with numerous embolised tumour cell aggregates in ectatic lymphatics of the serosa (lymphangiosis carcinomatosa); S = smooth muscle layer of the intestine; H&E, Bar:100 μm f Cytokeratin (CK) 20 positive keratin pearl. g Desmin expressing spindeloid cells with partially visible cross-striation. h Smooth muscle actin (SMA) positive fibers. i CD3 positive T-lymphocytes. j Glial fibrillary acidic protein (GFAP) positive astrocytes k Sox2 positive, columnar to cuboidal cells in tubular structures. f - k: Bars: 50 μm