Sudden death of a crossbred calf associated with a myocardial adenomatoid tumour

The only lesion found in a crossbred calf that died suddenly was a rare tumour in the myocardium of the left ventricle. The mass appeared similar to tumours discovered incidentally in the hearts of abattoir specimens in Italy, described as adenomatoid tumours. These are bimorphic tumours presumed to have a mesothelial origin. Although in a published study from Italy these tumours were considered incidental and clinically unimportant, I suggest that in this case the mass may have interfered with cardiac conduction, causing sudden death of the calf.

A Comparative Review of Canine and Human Rhabdomyosarcoma With Emphasis on Classification and Pathogenesis

Rhabdomyosarcomas are a diverse group of malignant mesenchymal neoplasms exhibiting variable levels of differentiation toward skeletal myocytes. Neoplastic cells may resemble relatively undifferentiated myoblasts, satellite cells, or more differentiated elongated spindle cells and multicellular myotubes. In veterinary medicine, classification into subtypes and variants is based on an outdated system derived from human pathology and is solely based on histologic characteristics. In contrast, classification of human rhabdomyosarcoma is based on histologic, immunohistochemical, and molecular diagnostic techniques, and subclassification has clinical and prognostic relevance. Relevance of tumor subtyping has not been established in veterinary medicine. Recent discoveries of components of the molecular pathogenesis and genomes of human rhabdomyosarcomas have led to new diagnostic techniques and revisions of the human classification system. The current classification system in veterinary medicine is reviewed in light of these changes. Diagnosis of rhabdomyosarcoma using histopathology, electron microscopy, and the clinical aspects of human and canine rhabdomyosarcomas is compared. The clinical features and biologic behavior of canine rhabdomyosarcomas are compared with canine soft tissue sarcomas.

Cardiac Angioleiomyoma in 44 Cattle in Japan (1982–2009)

A retrospective study was performed on primary cardiac tumors found in 44 cattle during meat inspection in Japan, using histology, immunohistochemistry, and electron microscopy. The age of affected cattle ranged from 10 to 129 months; 82% were less than 3 years old. In 38 hearts, the tumor was solitary; the remaining 6 hearts had multiple masses. All tumors were subendocardial and involved the papillary muscles and/or cardiac valves. Two histologic patterns were recognized; both included giant cells. Pattern 1 was characterized by interlacing fascicles of spindle-shaped cells; pattern 2 resembled cavernous hemangioma. The 2 patterns coexisted and were linked by transitional zones. Given the immunohistochemical reactivity and ultrastructure, the spindle-shaped cells were identified as smooth muscle cells and the giant cells as endothelial cells. Single cell and multicellular angiogenesis by giant cells was observed. The tumors were classified as cardiac angioleiomyoma. Subendocardial multipotential mesenchymal cells, persistent tissue of the endocardial cushion, or valvular interstitial cells were suspected as the origin.