Benign Mesenchymoma of the Heart in the Guinea Pig

Abstract

Thirty-six hundred ninety-eight guinea pigs of the Dunkin-Hartley strain from the breeding colony at Fort Detrick were necropsied. Four females had mesenchymomas of the heart. The tumors were similar histologically and were composed of multiple benign mesenchymal tissues which were amalgamated into a single mass. One tumor was composed of fibrous, angiomatous, adipose, cartilagenous, osscous, hematopoietic, myxomatous, and possibly smooth muscle tissues. Smooth muscle and myxomatous tissues were not found in the other tumors. All were benign and probably originated from the primitive mesenchyme of the heart.

Primary Leiomyosarcoma in the Heart of a Guinea Pig

“…Cardiac leiomyosarcomas are rare (B€ ultmann et al, 2001) and the prevalence of tumours of the cardiovascular system in guinea pigs is also very low (Manning, 1976). Single cases of a round cell sarcoma (Bender, 1925) and a fibrosarcoma (Athias, 1937) have been described and in four cases benign mesenchymomas were detected in the heart of a guinea pig (McConnell and Ediger, 1968). To our knowledge, the present case represents the first report of cardiac leiomyosarcoma in a guinea pig.…”