Diagnosis of intraocular lymphosarcoma in a dog by use of a polymerase chain reaction assay for antigen receptor rearrangement.

CASE DESCRIPTION: A 12-year-old castrated male mixed-breed dog was evaluated because of blepharospasm and blindness affecting both eyes.

CLINICAL FINDINGS: During examination and diagnostic testing of the dog, fine-needle aspirates of splenic nodules were examined microscopically and stage Vb multicentric large-cell lymphosarcoma was identified. Aqueocentesis was performed, and sample analysis revealed intraocular lymphosarcoma; B-cell neoplasia was confirmed by use of a PCR assay for antigen receptor rearrangement (PARR) performed on samples of aqueous humor. Secondary uveitis and glaucoma were detected bilaterally in addition to chronic superficial corneal ulcerations in the left eye.

TREATMENT AND OUTCOME: Treatment for abdominal and intraocular lymphosarcoma involving administration of vincristine, l-asparaginase, cyclophosphamide, doxorubicin, and prednisone was initiated. Secondary uveitis and glaucoma were controlled with topical treatment; however, the corneal ulceration did not resolve. Seven weeks following diagnosis, the dog died as a result of complications related to systemic neoplasia and chemotherapy.

CLINICAL RELEVANCE: In the dog of this report, intraocular lymphosarcoma was diagnosed via PARR performed on samples of aqueous humor. Moreover, the immunophenotype of the neoplastic cells was determined by use of that diagnostic technique. Because secondary uveitis is a common finding in dogs and cats with systemic lymphosarcoma, intraocular lymphosarcoma should be considered as a differential diagnosis; furthermore, investigation (eg, PARR performed on aqueous humor samples) to identify the presence of intraocular lymphosarcoma is warranted, thereby allowing targeted interventions to be considered in management of those patients.