Veterinary Medicine - June 2008 - (Page 314)

A challenging case PEER-REVIEWED tarsorrhaphy was performed by using 4-0 Dermalon (Syneture), and a No. 15 scalpel blade was used to incise the skin 5 mm from the eyelid edge in an elliptical fashion to allow for smooth skin apposition at closure. The orbital contents were removed by dissection with tenotomy scissors, which were kept as close to the bones of the orbit as possible. The medial and lateral orbital ligaments were transected, and the nictitating membrane was completely removed. The dissection was continued around the eye and mass until the optic nerve was encountered. The nerve was then transected, and the tissue was completely removed. Meticulous hemostasis was maintained to minimize any additional blood loss. To prevent excess indentation of the orbit and to optimize the cat’s appearance after surgery, sutures were placed across the orbital rim (from rim to rim) using 4-0 Dermalon in a continuous pattern. The subcutaneous tissue was closed with 4-0 Dexon S (Syneture) in a simple continuous pattern, and the skin was closed with 4-0 Dermalon in a simple interrupted pattern (Figure 4). Another unit of whole blood was given during the surgery, and at surgical completion, the cat’s PCV was 17%. The cat’s recovery from anesthesia was uneventful, and it was released to the owner that day. For pain management, the cat was given oral buprenorphine (0.12 mg/kg sublingually b.i.d. for three days). A two-week postoperative reevaluation with suture removal was scheduled. globe displacement.1 The mass was composed of neoplastic lymphocytes, completely obscuring the periorbital tissue and extraocular muscles. These cells also invaded the conjunctiva and eyelids and completely lled the shrunken globe. The cells had scant cytoplasm and round nuclei with densely stippled chromatin and a single prominent nucleolus and were arranged as diffuse sheets among a brovascular stroma. The conjunctiva was also in ltrated by lymphocytes, plasma cells, and neutrophils, and there were areas of necrosis and hemorrhage. The orbital tissue was completely invaded by neoplastic lymphocytes. No ReedSternberg cells—large abnormal lymphocytes that may contain more than one large pale nucleus with a prominent nucleolus and that indicate Hodgkinlike lymphoma—were seen. Immunohistochemical staining demonstrated that the cells were negative for CD3 T lymphocyte receptor and positive for CD79a B lymphocyte receptor, con rming the mass was a B-cell lymphoma. The diagnosis was non-Hodgkinlike, apparent primary conjunctival lymphoma. The histologic examination results indicated that neoplastic cells remained in the orbit, so the chance of mass recurrence was high. TWO- AND FOUR-WEEK POSTOPERATIVE RECHECKS At a recheck examination two weeks after surgery, the owner reported that the cat was eating and was alert and playful. Repeat blood tests revealed normal serum chemistry values and a normal PCV (32%). The cat still had reticulocytosis (reticulocytes = 22,620/µl) and increased nucleated red blood cells (0.1 x 103/µl), suggesting that the anemia had been due to blood loss and that erythrocyte production was suf cient. Since the tumor had been removed and the cat was doing well, treatment options for the lymphoma were discussed with the owner. It was recommended that a thorough check for metastases HISTOLOGIC EVALUATION Histologic evaluation of the orbital contents con rmed a diagnosis of conjunctival lymphoma (Figures 5 & 6). Since the tumor was extensive, it was dif cult to determine whether it originated in the orbit or the conjunctiva. The initial clinical presentation was consistent with a conjunctival tumor: a relatively slow progression and protrusion of the nictitating membrane and no forward 314 June 2008 VETERINARY MEDICINE

Table of Contents Feed for the Digital Edition of Veterinary Medicine - June 2008

Veterinary Medicine - June 2008 Contents Leading Off Clinical Exposures Idea Exchange A Challenging Case: Conjunctival Lymphoma in a Cat Updates on Canine Hypoadrenocorticism Product Preview CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller Clinical Edge - June 2008 Table of Contents Managing Diabetes Mellitus in Cats: What Makes it Work? Porcine Insulin Zinc Suspension in the Management of Feline Diabetes Mellitus Monitoring Diabetes Mellitus in Diabetic Cats Feline Diabetes Mellitus: Important Client Communication Points

Veterinary Medicine - June 2008

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