[Two cases of malignant cardiac tumors attached on the anterior mitral valve]

Two cases were reported in which malignant cardiac tumors attached to the mitral valve were diagnosed during their lifetimes using two-dimensional echocardiography. Case 1 was a 29-year-old man with speech disturbance and left hemiparesis. Histological examination of the specimen excised from the cardiac tumor during the operation revealed mesenchymal chondrosarcoma, which is extremely rare etiologically and has never been reported so far. Case 2 was a 62-year-old woman complaining of paroxysmal nocturnal dyspnea and chest pain. The diagnosis of malignant histiocytosis was made from the pathological examination of biopsy specimen taken from the rib metastasis. Using two-dimensional echocardiography, characteristic findings for the cardiac tumor were obtained. The tumor echo in Case 1 showed, unlike to that reported for myxoma, two different echogenic layers; the outer dense and the inner light in the echo density. On surgery, tumor echo was revealed to reflect the cystic lesion. In Case 2, two-dimensional echocardiography on admission revealed two separate tumor echoes which attached to the mitral valve and left atrial wall region, respectively. Within two months, they grew rapidly and finally fused into one mass resulting in so-called ball valve syndrome. Phonocardiographically, the tumor plop in Case 1 was high-pitched in quality, and was extinguished completely after the tumor was resected. The tumor plop in Case 2 was not audible on admission, but became evident after fusion of the tumor echoes and was associated with a presystolic murmur.