Blindness associated with nasal/paranasal lymphoma in a stallion.

This study documents the case of a 29-year-old stallion that went blind due to a large tumor identified as diffuse large B-cell lymphoma located in the nasal and paranasal cavities. The growth and expansion of this tumor led to significant damage to the optic nerves, resulting in blindness.

Case Presentation

• This research focuses on a 29-year-old stallion that developed blindness in both eyes. The stallion had suffered from chronic purulent nasal discharge prior to this development.
• On examination, it was discovered that a mass was occupying regions in the stallion’s right caudal nasal cavity and right paranasal sinuses, inclusive of the maxillary, palatine and sphenoidal sinuses.
• The destructive growth of this mass resulted in the displacement of the right-side turbinal and paranasal septal bones, along with the cribriform plate of the ethmoid bone.

Progression and Impact of the Lymphoma

• The tumor grew to the extent of invading and implicating the right optic nerve.
• Furthermore, the mass extended to compress the left optic nerve and optic chiasm, intensifying its invasion to the base of the skull.
• Both the optic nerves and optic chiasm showed signs of degeneration under histological examination.

Diagnosis and Classification

• The mass was identified as a lymphoma, which is a type of cancer developing from lymphocytes, a kind of white blood cell.
• Both morphological and immunohistochemical classification recognized the lymphoma as a diffuse large B-cell lymphoma, one of the most common subtypes of non-Hodgkin’s lymphoma in adults.

Conclusion and Significance of the Case

• This case established that the cause of the stallion’s blindness was the degeneration of the optic nerves and chiasm. These degenerations were consequences of the lymphoma in the nasal and paranasal cavities.
• According to researchers, this is the first reported occurrence of equine blindness due to optic nerve degeneration in the presence of lymphoma.