Primary invasive ocular squamous cell carcinoma in a horse.

This research article speaks about a unique case where a 12-year-old Haflinger gelding horse was diagnosed with invasive ocular squamous cell carcinoma, a condition never observed before in horses. The cancer was initially localized to the eye’s surface but later progressed to infiltrate the cornea and deeper structures of the eye, leading to the surgical removal of the globe.

Introduction

• The research paper focuses on a unique veterinary medical case involving a 12-year-old Haflinger gelding horse admitted to the University of Zurich’s veterinary medical teaching hospital.
• The horse was diagnosed with squamous cell carcinoma, a type of skin cancer that commonly affects the outer layers of the skin but can occur in other tissues, including the eye.

Primary Diagnosis

• The horse was initially presented with a light-pink raised mass on the temporal limbus and conjunctiva (the outer edge and the lining of the eyeball) of the left eye.
• The detection of squamous cell carcinoma was confirmed histologically (microscope examination of tissue) following the procedures of keratectomy (removal of cornea) and cryotherapy (the use of extreme cold to destroy abnormal cells).

Follow-Up & Treatment

• Within seven months, a secondary mass was found, characterized by a smooth, progressively enlarging pink mass within the cornea of the left eye.
• This mass was not only infiltrating the dense fibrous, translucent corneal stroma but seemed to protrude into the anterior chamber (front part of the eye).
• Considering the advanced stage and the invasive nature of the tumor, the globe (the eyeball) was surgically removed and submitted for further pathological examination.

Final Diagnosis & Conclusion

• A final histologic diagnosis revealed that the squamous cell carcinoma had deeply invaded the corneal stroma, infiltrated the uveoscleral meshwork and iridocorneal angle (parts of the eyeball), causing intraocular extension (growth within the eyeball).
• This research paper illustrates the first detailed description of a limbal squamous cell carcinoma with invasion into the cornea and uvea (the middle layer of the eye) in a horse, contributing to the existing literature on animal oncology and equine ophthalmology.