Myocardial hamartoma of the right atrium in a dog.
A myocardial hamartoma of the right atrium is described in an 8-year-old dog that died from pneumonia. At necropsy, a firm, mottled, dark-brown right atrial appendage, of normal shape but slightly enlarged, was found incidentally. On section, the right atrial appendage was composed of a grey-tan, solid mass. Histological features of the mass were as follows: the component cells were mature cardiac muscle cells; the mass contained all of the components of the normal heart wall (i.e., epicardium, myocardium and endocardium), but the arrangement of the component tissues was disorganized; growth of the mass was non-invasive, and continuity of the component cells with adjacent normal myocardial cells was evident, suggesting a congenital origin. This appears to be the first report of congenital myocardial hamartoma in any animal other than man.
Machida
N
N
Department of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
Katsuda
S
S
Yamamura
H
H
Kashida
Y
Y
Mitsumori
K
K
D000818:Animals; D009202:Cardiomyopathies / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D017809:Fatal Outcome; D005260:Female; D006222:Hamartoma / Q000473:pathology / Q000662:veterinary*; D006325:Heart Atria / Q000473:pathology; D009206:Myocardium / Q000473:pathology*