Fig. 1

Mulard duck (case 1) with a teratoma in the cranial coelomic cavity. a Coelomic mass (11 × 13 × 3.5 cm) attached to the heart (H) and lung (L). b Multiple epithelial cysts containing desquamated, orthokeratotic epithelial cells, blood-filled cysts (asterisk) and glandular structures (arrows), H&E. Bar: 100 μm. c Islands of trabecular bone tissue (B) containing haematopoietically active bone marrow as well as cartilage clusters (C) surrounded by adipose tissue (A), H&E. Bar: 200 μm. d Pan-Neurofilament (NF) positive axonal structures. e Multifocal weakly Olig2 positive cells in a tissue with a honeycomb-like appearance. f Glial fibrillary acidic protein (GFAP) positive astrocytes. g CD3 positive T-lymphocytes. h Desmin expression in a bundle of spindeloid cells. i Sox2 positive, columnar to cuboidal cells in tubular structures. d - i: Bars: 50 μm