Clinical and histopathological classification of feline intraocular lymphoma.

This retrospective study aimed to describe and classify cats with intraocular lymphoma, determine the proportion of cases with presumed solitary ocular lymphoma (PSOL) compared with ocular manifestations of multicentric disease and assess the clinical outcomes of these patients. One hundred seventy-two cases identified through biopsy submissions were reviewed histologically; 163 of these cases were subtyped according to the WHO classification system. Cases were categorized as having PSOL or ocular lymphoma with suspected systemic involvement (SSI) based on submission forms and follow-up data. The majority of cases exhibited concurrent uveitis (75%) and secondary glaucoma (58%). Diffuse large B-cell lymphoma was the most common subtype (n = 86; 53%), followed by peripheral T-cell lymphoma (n = 44; 27%). Other subtypes included anaplastic large T- (n = 8; 5%) and B-cell (n = 4; 2.5%) lymphomas, and 15 cases (9%) were negative for all immunohistochemical markers. In sixty-nine cases (40%), adequate clinical data and sufficient survival data were obtained to distinguish PSOL from SSI. PSOL comprised the majority of cases (64%), while 36% had SSI. When covarying for age at diagnosis, the median survival time was significantly higher (P = 0.003) for cases of PSOL (154 days) versus those with SSI (69 days); hazards ratio of 0.47 for PSOL (95% CI: 0.241-0.937). The subtype of lymphoma did not affect survival time. Cats with PSOL represent a greater proportion of the disease population, and this subset of cats with intraocular lymphoma has a better clinical outcome.

Clinical and pathological classification of canine intraocular lymphoma.

The objectives of this retrospective study of 100 dogs with intraocular lymphoma were to describe the histomorphologic and immunohistochemical features of canine intraocular lymphoma, determine the proportion of cases with presumed solitary ocular lymphoma (PSOL) compared to multicentric disease, and assess the clinical outcomes of these patients. Selected cases from Penn Vet Diagnostic Laboratory and Comparative Ocular Pathology Lab of Wisconsin (2004-2015) were evaluated and subtyped using the WHO classification system. Peripheral T-cell lymphoma and diffuse large B-cell lymphoma were the two most common subtypes. Questionnaires were distributed to the referring veterinarians and veterinary ophthalmologists inquiring about clinical signs at time of enucleation, staging, patient outcome, treatment, and disease progression. Cases were categorized as PSOL if only ocular involvement was noted at the time of diagnosis based on the clinical staging criteria. The majority of cases (61%) did not have systemic involvement at the time of diagnosis, and these cases did not progress postoperatively. Median survival time (MST) was significantly higher for the presumed solitary intraocular cases: 769 vs. 103 days, hazard ratio of 0.23 (95% CI: 0.077-0.68). The subtype of lymphoma did not affect survival time. The results of this study suggest two significant points of clinical interest: the majority of dogs (61%) presented without signs of systemic involvement of lymphoma at the time of enucleation, and dogs with only ocular involvement showed no disease progression postenucleation.