This case report describes a Red Holstein heifer with a thymic lymphoma (ly
mphosarcoma; malignant lymphoma). The heifer was presented because of a sev
ere swelling at the throat and ventral neck region. Based on the clinical e
xamination the diagnosis of thymic neoplasia was made. Because of the poor
prognosis the heifer was euthanised and autopsied. Histopathological examin
ation revealed a thymic lymphoma.