High-Grade Canine T-cell Lymphoma/Leukemia with Plasmacytoid Morphology: A Clinical Pathological Study of Nine Cases

• Published in: Journal of veterinary diagnostic investigation Vol. 15; no. 4; pp. 330 - 337
• Main Authors: Ponce, F, Magnol, J.P, Marchal, T, Chabanne, T, Ledieu, D, Bonnefont, C, Felman, P, Fournel-Fleury, C
• Format: Journal Article
• Language: English
• Published: United States 01.07.2003
• Subjects: Animals; bone marrow; chemotherapy; cytoplasm; disease course; Disease-Free Survival; Dog Diseases - pathology; Dogs; Female; hypercalcemia; Immunophenotyping - veterinary; leukemia; Leukemia, T-Cell - pathology; Leukemia, T-Cell - veterinary; lymphoma; Lymphoma, T-Cell - pathology; Lymphoma, T-Cell - veterinary; Male; phenotype; Prognosis; Sex Ratio
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063870301500405

The aim of this study is to determine the clinical, morphological, and immunophenotypical presentation of 9 cases of a particular type of canine T-cell lymphoma/leukemia. The morphological presentation was a diffuse infiltration of small, medium-sized, or large blast cells with eccentric nuclei, hyperbasophilic cytoplasm, and a juxtanuclear, pale cytoplasmic area, giving a plasmacytoid appearance and suggesting a B-cell morphology. Surprisingly, all 9 cases were of T-cell phenotype (CD3(+)). Among the 7 immunophenotyped cases, 4 were CD4(–)/CD8(+), 2 CD8(+)/CD4(+), and 1 CD4(+)/CD8(–). The median Ki-67 index was 65.7%, which placed this lymphoma in the high-grade group. This type of lymphoma/leukemia was found in dogs between 1 and 11 years of age, with a median age of 5.8. The male-female ratio was 0.8 for a reference population of 1.04. The most significant clinical findings were lymphadenopathy either generalized or localized in all cases, a mediastinal mass in 4 cases, bone marrow involvement in 7 cases, hypercalcemia in 4 cases, along with an aggressive clinical course and a poor response to chemotherapy in all cases, with a median disease-free survival time of 3 months.