A case of umbilical cord teratoma in an aborted foal.

This study reports a rare case of an umbilical cord teratoma in a foal that was aborted by a 16-year-old mare. The multi-layered teratoma was attached to the fetus’s umbilical cord and had a variety of tissue types within it.

Background

• The study focuses on a rare termination in a 16-year-old primiparous mare – meaning this was her first pregnancy – that resulted in the expulsion of a normally developed fetus with an umbilical cord teratoma.
• This case is notably rare, especially in the field of veterinary science as such an occurrence of an umbilical cord teratoma has only been reported once before in animal literature.

The Teratoma

• The teratoma, a tumour usually composed of different types of tissues, was a large oval mass measuring approximately 20 cm × 30 cm × 20 cm. It was attached to the umbilical cord of the fetus.
• Upon examination, the teratoma showcased a variety of complex structures. It had multifocal cystic structures (abnormal sacs filled with fluid), foci of mineralization (areas where tissues became hardened due to deposit of minerals), and diffuse hemorrhages (widespread bleeding).

Histological Examination

• The histological (microscopic) examination of the mass revealed it to be composed of a mix of varying tissue types, which are characteristic of teratomas.
• This included cartilage, bone, mesenchymal stroma (connective tissue), adipose tissue (fat), vascular structures (blood vessels), smooth muscle, ciliated epithelium (the surface layer of cells), squamous cornifying epithelium (type of skin surface cells), and undifferentiated germ cells – the type that can give rise to various other types of cells.
• There were also areas of necrosis (tissue death) and further mineralization observed in the composition of the teratoma.

Diagnosis

• After rigorous examination, the mass was officially diagnosed as an umbilical cord teratoma.
• This discovery is significant as it contributes to a rare set of veterinary findings and deepens understanding of related conditions in animals, especially in horses.