Epibulbar melanoma in a foal

Area of Science:

• Veterinary Ophthalmology
• Equine Pathology
• Ophthalmology

Background:

• Epibulbar melanomas are rare in foals.
• Early diagnosis and treatment are crucial for ocular tumors.

Observation:

• A 6-month-old foal presented with an epibulbar mass, initially suspected as staphyloma or congenital anomaly.
• Surgical excision was attempted but the tumor's infiltrative nature required enucleation.
• Histopathology confirmed a heavily pigmented, infiltrative melanocytic neoplasm with choroidal invasion.

Findings:

• The epibulbar melanoma exhibited characteristics of a low-grade malignant neoplasm.
• Infiltration into the cornea, sclera, and choroid was confirmed histopathologically.
• Despite invasion, no recurrence was observed 14 months after initial surgical debulking and subsequent enucleation.

Implications:

• This case highlights the importance of considering melanoma in equine ocular masses.
• Understanding the infiltrative potential of epibulbar melanomas is critical for surgical planning.
• Further research into equine ocular tumor biology may improve diagnostic and therapeutic strategies.