Canine lymphomas diagnosed in southern Brazil from 2000 to 2017: epidemiology and immunophenotype

ABSTRACT: Lymphoma is a neoplasm that originates from solid hematopoietic tissues and is one of the most common tumors in dogs. The goal of the present study was to perform a retrospective study of canine lymphomas diagnosed at the “Laboratório Regional de Diagnóstico”, at the “Faculdade de Veterinária” of the “Universidade Federal de Pelotas” (LRD-UFPel) from 2000 to 2017, to determine the epidemiology and anatomical distribution, and to evaluate the histopathological and immunohistochemical aspects of each case according to the adapted Kiel classification. The protocols for necropsies and biopsies in the laboratory were reviewed. Lymphoma was diagnosed in 77 dogs. Approximately 37.7% (29/77) of affected dogs had no defined breed, while dogs with defined breeds accounted for 58.4% (45/77) of the diagnoses. The occurrence in males (40/77) was slightly higher than that in females (36/77), and the mean age was 8.1 years (1.4-17 years). The most affected age group was between six and 10 years of age with 31 cases (40.2%). Regarding the anatomical classification, the multicentric form was the most prevalent, accounting for 71.4% (55/77) of the diagnoses. In 40 cases that immunophenotyping was performed, B-cell lymphomas represented 62.5% of the diagnoses (25/40), while T-cell lymphomas corresponded to 37.5% of the diagnoses (15/40). The degree of malignancy according to the modified Kiel classification was low in 35% of lymphomas (14/40) and high in 65% of cases (26/40). The multicentric form was more frequent in the region of influence of the LRD-UFPel. Identification of the immunophenotype can improve the quality of life and survival in affected dogs since it allows the most appropriate treatment for each patient.

Epidemiology, clinical and cytological features of lymphoma in Boxer dogs

The aim of this study was to evaluate the epidemiology, clinical and laboratory characteristics of canine lymphomas as well as some aspects of treatment outcomes. The study was conducted on Boxer dogs with lymphoma diagnosed by cytology and immunocytochemistry (CD3 and CD79 alpha). During the study period, lymphoma was diagnosed in 63 Boxers; 86.8% were T-cell (based on the Kiel classification: small clear cell lymphoma, pleomorphic small cell lymphoma, pleomorphic mixed T-cell lymphoma, pleomorphic large T-cell lymphoma, lymphoblastic lymphoma/acute lymphoblastic leukaemia) and 13.2% were B-cell lymphomas (according to the Kiel classification: B-cell chronic lymphocytic leukaemia, centroblastic/centroblastic polymorphic lymphoma). Overall survival (OS) was significantly longer in dogs with low-grade than with high-grade lymphoma (median OS of 6.8 and 4.7 months, respectively; P = 0.024). OS was not influenced by WHO clinical stage, WHO clinical substage, presence of splenomegaly, early administration of glucocorticoids or the time from the first presentation to the beginning of chemotherapy. There are no significant differences in clinical and laboratory parameters between low-grade and high-grade lymphomas. Boxer dogs are predisposed to T-cell lymphoma, with a predominance of high-grade tumour, especially pleomorphic, mixed small and large T-cell subtype. It is possible that Boxer dogs may respond less favourably to chemotherapy than patients of other breeds.

Immunocytoma: A Retrospective Analysis From St Bartholomew's Hospital—1972 to 1996

PURPOSE: To analyze the presentation features and outcome for patients with immunocytoma (IMC) managed at St Bartholomew's Hospital (SBH), London, United Kingdom, between 1972 and 1996. Outcome was compared with that of patients with small lymphocytic lymphoma (SLL)/B-cell chronic lymphocytic leukemia (B-CLL) treated at SBH during the same period. PATIENTS AND METHODS: One hundred twenty-six patients with newly diagnosed IMC were identified. Patients were subclassified (using the Kiel classification) as having lymphoplasmacytoid (n =92), lymphoplasmacytic (n = 24), polymorphous (n = 9), or undetermined (n = 1) IMC. Six patients (5%) had stage I to IIE disease; the rest had advanced disease. Treatment was given according to disease stage. Seven patients were managed expectantly. RESULTS: Eighty-two (69%) of 119 patients responded to treatment, but complete remission was seen in only 15 (13%) of 119. Treatment failed in 29 (24%) of 119 patients. There were three treatment-related deaths; five patients were not assessable for response. When survival of patients with IMC was compared with that of patients with B-CLL/SLL, a significant difference was found (P < .01); this difference was maintained when only patients in whom the diagnosis was based on lymph node biopsy were considered (P = .01). A comparison of the three IMC subgroups showed that there was a trend (P = .06) toward a difference between B-CLL/SLL and the lymphoplasmacytoid subtype. CONCLUSION: Patients diagnosed with IMC are generally older and present with advanced disease. Conventional therapies usually result in incomplete responses of short duration. Overall, these results support the proposed World Health Organization reclassification of IMC to include lymphoplasmacytoid lymphoma (Kiel classification) as a variant of B-CLL/SLL.