Immature T cell neoplasms in three young cattle

Area of Science:

• Veterinary Pathology
• Oncology
• Immunology

Background:

• Immature T cell neoplasms can affect young cattle, impacting the thymus.
• Distinguishing between different types of T cell neoplasms is crucial for accurate diagnosis and understanding disease pathogenesis.

Observation:

• Three cases of immature T cell neoplasms in young Holstein cattle are presented.
• Case 1: An 86-day-old calf with precursor T lymphoblastic leukemia affecting bone marrow and spleen.
• Cases 2 & 3: A steer and heifer with thymic γδ T cell lymphomas, showing distinct histological and immunohistochemical profiles.

Findings:

• Precursor T lymphoblastic leukemia (calf leukosis) differs significantly from thymic γδ T cell lymphomas in histological presentation and organ involvement.
• Thymic γδ T cell lymphomas showed obliteration of thymic architecture and stromal fibrosis, with less severe splenic and hepatic involvement compared to leukemia.
• Immunohistochemical analysis revealed differential expression of WC1 and CD8 markers between the leukemia and lymphomas.

Implications:

• The findings support classifying precursor T lymphoblastic leukemia and thymic γδ T cell lymphomas as independent disease entities in cattle.
• This differentiation aids in understanding the distinct biological behavior and potential treatment strategies for these bovine neoplasms.
• Highlights the importance of detailed histological and immunohistochemical evaluation for accurate diagnosis of T cell neoplasms in veterinary oncology.