Cysts in the atrioventricular valves.

In a cow under 12 months old, an intravalvular cyst was observed in the atrioventricular valve of 0.5 cm in diameter, of white color, thin-walled and with semi liquid contents.

Histopathological analysis demonstratded a single valve cyst with a thin wall formed by spindle shaped stromal cells with abundant extracellular matrix and lined with endothelium. The liquid inside stained eosinophilic, typical of colloidal protein.

It is a congenital valve disorder, relatively frequent in cattle, with no pathological relevance. Its originIt is believed to be an ectasia of lymphatic or blood vessels.

Atrioventricular intravalvular cyst.

Intraparenchymal cyst in the atrioventricular valve, viewed from the opposite side of Figure 1.