Supposed primary conjunctival lymphoma in a dog.

Area of Science:

• Veterinary Oncology
• Ophthalmology
• Immunohistochemistry

Background:

• Primary ocular and adnexal lymphomas are infrequently documented in canine medicine.
• The clinical behavior and characteristics of these tumors remain poorly understood.

Observation:

• A 7-year-old dog presented with a conjunctival mass on the lower eyelid and lateral canthus.
• The mass was histologically identified as a B-cell neoplasm, immunohistochemically positive for CD20 and CD79a, and negative for CD3.
• The dog had a prior surgical history of a similar tumor in the same eye three years earlier.

Findings:

• A diagnosis of presumed primary B-cell conjunctival lymphoma was established based on microscopic and immunohistochemical analysis.
• No evidence of metastasis was detected during either presentation.
• The tumor did not recur within one year following surgical excision.

Implications:

• This case underscores the rarity of conjunctival involvement in canine ocular lymphoma.
• The three-year recurrence interval following surgery suggests a potentially indolent or unique clinical course for this specific tumor.
• Further research into canine ocular lymphomas is warranted to better characterize their behavior and optimize treatment strategies.