Retrobulbar dermoid cyst in a horse: a case report.

The research article focuses on a unique case of a retrobulbar dermoid cyst found in a 4-year-old Andalusian horse. This unusual find, characterized by exophthalmos (abnormal protrusion) of the right eye and swelling of the right supraorbital fossa, was surgically removed and no recurrence has developed.

Case Presentation

• The 4-year-old Andalusian horse that was presented had a 3-month history of exophthalmos in the right eye. This abnormal condition of the eye, where it appears protruded or bulging out of the socket, was observed following an incident of blunt head trauma.
• Additionally, a soft swelling of the right supraorbital fossa (the hollow area above the orbit of the eye) was observed in the horse.

Diagnosis

• An ultrasonographic examination revealed an anecogenic (free of internal echoes) mass measuring 5 cm in diameter in the retrobulbar space, the area behind the eyeball.
• The scientists conducted a centesis of the mass through the supraorbital fossa; this process involved extracting a small sample of fluid from the mass for testing.
• The extracted fluid was found to be serous with a total protein of 7.2 g/dL, and density of 1040. The absence of cells in the sample led to a provisional diagnosis of a cyst.

Surgical Treatment and Outcome

• The suspected cyst was surgically removed, and subsequent histologic analysis confirmed the diagnosis of a retrobulbar dermoid cyst.
• The surgery appeared to be successful as no recurrence of the cyst was observed 18 months following the procedure.
• This case is significant as, according to the authors, there are no known previous reports of retrobulbar dermoid cysts in horses.

Discussion

• The authors discuss the possible causes, placement, and success rate of surgical removal of dermoid cysts.