Pleomorphic corneal sarcoma resembling malignant peripheral nerve sheath tumor in a horse.

The research discusses a rare case of pleomorphic corneal sarcoma that resembles a malignant peripheral nerve sheath tumor in a 14-year-old Haflinger gelding.

Case Presentation

• A 14-year-old Haflinger gelding horse was seen with a protruding mass in its right eye, particularly in the cornea.
• The mass was surgically removed and sent for further testing and examination specifically, histopathologic and immunohistochemical study.

Primary Diagnosis

• Based on the early findings, the preliminary diagnosis was that the mass was a corneal sarcoma, most likely a fibrosarcoma. Fibrosarcoma is a type of malignant tumor composed of fibrous or connective tissue.
• However, further immunohistochemical results indicated a different conclusion.

Immunohistochemical Findings

• The immunohistochemical examinations disclosed the mesenchymal origin of the cancerous cells. Mesenchymal cells can develop into many different types of cells in the body, including those found in the muscles, lungs, and bones.
• These outcomes suggested a type of cancer called malignant peripheral nerve sheath tumor (MPNST) – these are tumors that develop in the cells surrounding the peripheral nerves.

Uncommon Occurrence

• Corneal mesenchymal neoplasms, which this case appears to be, are notably rare in humans and domestic animals.
• The cause for this particular tumor was not established. The possibility of infection with the bovine papillomavirus was tested for, but was not detected.