[Cardiac myxoma. Ultrastructural and immunohistochemical study of two cases]. / Myxome cardiaque. Etude ultrastructurale et immunohistochimique de deux cas.

Two cases of cardiac myxoma studied by electron microscopy and by immunohistochemical methods are reported. In one case, the initial clinical manifestation was systemic embolization, and histological sections from the arterial deobstruction material set the diagnosis of an embolizing cardiac myxoma. In the second case, the investigations of a post-capillary pulmonary hypertension with echocardiography disclosed a left intraauricular tumor. Ultrastructural studies demonstrated mesenchymal tumor cells of various degrees of differentiation characterized by numerous cytoplasmic microfilaments and intermediate-sized filaments. The most differentiated cells were surrounded by a continuous basement membrane; there were intracellular junctions and microvilli. Furthermore these cells contained numerous micropinocytosis vesicles, several Weibel-Palade bodies and an abundant rough endoplasmic reticulum. Analysis of their cytoskeleton, using indirect immunofluorescnece techniques, showed that these cells were laden with actin and myosin microfilaments; the intermediate filaments were composed of vimentine. Staining with anti-desmin and anti-prekeratin sera remained negative. These results contribute to confirm that cardiac myxomas represent tumors originating from the primitive multipotential mesenchymal cells. An obvious tendency to differentiate into endothelial cells is noted in the two cases studied.

[Sarcoidosis and portal hypertension (author's transl)]. / L'hypertension portale dans la sarcoidose.

A new case of portal hypertension associated with hepatic sarcoïdosis is reported. The authors reviewed 23 other cases in the literature, they underline diagnostic difficulties of which the etiology remains unclear. Surgical treatment seems to be the best in comparison with corticotherapy. Postoperative encephalopathy may appear till 8 years postoperatively. Hepatic atrophy rather than sarcoïdosis must be responsible for it.