Extranodal Lymphoma With Adnexal and Suspected Intracranial Involvement in a Dog.

Abstract

Objective: To describe the clinical and pathological characteristics of an unusual presentation of extranodal lymphoma in a dog.

Animal studied: An eleven-year-old female spayed mixed breed dog presented to the UGA Ophthalmology Service for evaluation of a large, rapidly growing, right upper eyelid and medial canthal mass. The mass measured 2.2 cm in diameter and compressed the anterior chamber. The remainder of the right eye and the left eyelids and eye were normal. Approximately 1 month prior, the patient underwent radiation therapy for treatment of a brain mass in the piriform lobe, suspected to be a glioma.

Treatment and progression: Biopsy of the adnexal mass revealed large B-cell lymphoma. A repeat brain MRI revealed resolution of the previously diagnosed mass. Enucleation (with wide upper eyelid margins) for comfort and definitive diagnosis was originally planned. However, a new left lower eyelid mass developed, and the right eyelid mass continued to grow. Treatment assuming large B-cell nonepitheliotropic adnexal lymphoma with potential intracranial involvement was initiated via a modified CHOP-15 chemotherapy protocol. The eyelid masses decreased in size within the first week and resolved within 3 weeks of treatment. Despite an initial positive response to chemotherapy, new cutaneous masses developed 3 months after initial diagnosis; the patient's quality of life declined, and euthanasia without necropsy was elected.

Conclusion: Diagnosis of adnexal lymphoma in this patient prompted reevaluation of previously diagnosed intracranial disease and directed alternative systemic treatment.