Peer-reviewed veterinary case report
Bilateral testicle teratoma in an equine fetus: A rare case.
- Journal:
- Journal of equine veterinary science
- Year:
- 2025
- Authors:
- Nieman, R T et al.
- Affiliation:
- Department of Veterinary Medicine at Metodista University and Sã · Brazil
- Species:
- horse
Plain-English summary
In this unusual case, a pregnant mare that was 310 days along lost her fetus due to a rare condition called bilateral testicular teratoma, which means there were abnormal growths in both testicles of the fetus. This condition led to complications during birth because the fetus's abdomen was swollen. The diagnosis was made by examining the tissues, which showed a mix of different types of cells, including bone, cartilage, and skin with hair follicles. This case highlights a very rare occurrence in horses, and unfortunately, it resulted in the loss of the fetus.
Abstract
Fetal loss in mares can result from a range of causes, including infectious agents or noninfectious conditions such as neoplasia, which may originate from either the fetus or the dam. Among neoplastic conditions, teratomas are rarely reported and, to date, have not been described in the equine fetal testis. Teratomas arise from the partial differentiation of pluripotent germ cells and may occur in young and adult horses, typically in cryptorchid testes. Their gross and histopathological features vary widely between cases. This report describes a rare case of bilateral fetal testicular teratoma in a 310-day pregnant mare, which resulted in dystocia due to fetal abdominal distension. The diagnosis was based on gross and histopathological findings, which revealed small-caliber blood vessels, cystic structures, and a variety of differentiated tissues in both testes, including bone, cartilage, and skin with hair follicles, connective tissue, and adipose tissue.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/40562086/