[Clinical incidence of primary cardiac tumors]

Recently, clinical diagnostic methods for heart disease, especially echocardiography, have remarkably progressed and the incidence of cardiac tumors increased. This study investigated the characteristics of tumors in 115 patients with primary cardiac tumor, diagnosed histologically in 1993-1994, in collaboration with 126 university hospitals in Japan. Histological diagnosis, location, initial clinical manifestations and prognosis of cardiac tumors are reported. Of the 115 patients, 98 (85%) had primary benign tumor. Myxoma was the most common histological group (91 cases). Primary malignant cardiac tumors occurred in 17 patients (15%) of which rhabdomyosarcoma was the most frequent (5 cases). Sixty percent of patients with myxoma were female, a similar ratio to the proportion of female patients with other primary cardiac tumors. Most patients with myxoma had the tumor in the left side of the heart [76 cases (84%) in left side, 12 (13%) in right side, 3 (3%) in both sides]. In contrast, the primary malignant cardiac tumors occurred more in the right side of the heart rather than in the left side (eight in right side, six in left side). Embolization was the characteristic initial clinical manifestation for myxoma. There were no patients with initial manifestation of embolization in the other histological groups. Reflecting the recent progress and spread of clinical diagnostic methods, 17% of all patients were discovered asymptomatically. All patients with myxoma who were asymptomatic underwent operation, and there were no surgical deaths. In contrast, only one patient with primary malignant cardiac tumor could survive longer than a year. In conclusion, the progress and the spread of cardiovascular imaging has contributed to the early diagnosis of primary cardiac tumors. These data demonstrate new clinical and pathological characteristics of primary cardiac tumors seen in recent cardiologic practice in Japan.