Machida N, Hoshi K, Kobayashi M, Katsuda S, Yamane Y
Department of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
J Comp Pathol. 2003 Nov;129(4):320-4. doi: 10.1016/s0021-9975(03)00049-5.
A case of cardiac myxoma arising from the tricuspid valve is described in an 8-year-old dog that had suffered intermittent episodes of syncope. At surgical operation, a large, irregular, gelatinous mass was found attached to the septal leaflet of the tricuspid valve. The excised tumour, measuring 5x4x3.5 cm, had a grey-to-yellow, friable, mucoid, multilobulated and polypoid appearance, with focal haemorrhage. Histologically, the tumour consisted of a hypocellular mass of a myxoid matrix, rich in acid mucopolysaccharides, with a supporting structure of spindle-like, elongated or stellate cells scattered in an abundant stroma. The surface of the mass was covered by a single layer of endothelial-like cells. Immunohistochemistry revealed that the surface cells of the mass were positive for the endothelial marker CD34 and the constituent cells within the mass reacted positively and uniformly with antibodies to vimentin and alpha-smooth muscle actin. The dog died 36 h after the operation and, at necropsy, wide dissemination of myxomatous embolization to the intrapulmonary arteries was found.
本文描述了一例8岁患有间歇性晕厥的犬只，其三尖瓣发生心脏黏液瘤。手术时，发现一个大的、不规则的、凝胶状肿物附着于三尖瓣隔叶。切除的肿瘤大小为5×4×3.5厘米，呈灰黄色、质脆、黏液样、多叶状及息肉样外观，伴有局灶性出血。组织学上，肿瘤由黏液样基质的低细胞性肿块组成，富含酸性黏多糖，有梭形、细长或星状细胞的支持结构散在于丰富的间质中。肿物表面覆盖单层内皮样细胞。免疫组化显示，肿物表面细胞内皮标志物CD34呈阳性，肿物内的组成细胞对波形蛋白和α-平滑肌肌动蛋白抗体呈阳性且均匀反应。该犬术后36小时死亡，尸检时发现肺内动脉广泛存在黏液瘤性栓塞。
