Serous cystadenoma in a normally cyclic mare with high plasma testosterone values.

This research paper reveals the discovery of a Serous cystadenoma in a 16-year-old Thoroughbred mare with typical estrous cycles via histological examination. It investigates how the removal of this cystadenoma led to a decrease in high plasma testosterone levels.

Background

• The study revolves around a 16-year-old Thoroughbred mare which was diagnosed with Serous cystadenoma, a type of tumor, in one of her ovaries.
• The mare, interestingly, had normal estrous cycles despite the presence of the tumor. The estrous cycle is the reproductive cycle in most female mammals, similar to the menstrual cycle in humans.

Diagnosis

• The tumor was diagnosed through histologic examination. Histology is the study of microscopic anatomy of cells and tissues, typically carried out with a microscope.
• Anomalies in the mare’s right ovary were detected through palpation and ultrasound examination per rectum which revealed an excessive number of follicles.
• Notably, the ovulation fossa, a unique structure to the equine ovary where ovulation occurs, was palpable in the affected ovary, suggesting typical reproductive activity.
• The mare’s left ovary appeared to be functioning normally.

Plasma Testosterone Values

• Before the removal of the cystadenoma, the mare had high plasma testosterone values ((0.15 ng/ml)). Testosterone is predominantly a male hormone, but female bodies also produce it in smaller amounts. Unusually high levels could indicate health problems.

Post-Removal Findings

• After the removal of the ovarian tumor, the mare’s plasma testosterone levels decreased considerably to normal levels ((0.09 ng/ml)), signifying that the presence of the Serous cystadenoma might have been causing the increased testosterone production.