From January 1978 to February 1999, 120 patients (42 males and 78 females) with cardiac
myxoma (115) or
myxosarcoma (5) underwent surgical excision or biopsy. There were 5 early postoperative deaths (mortality, 4.2%). Seventy-three survivors were followed up for 0.75 to 20.25 years (mean, 9.42 years); they comprised 4
myxosarcoma patients who all had recurrence or
metastasis, and 69
myxoma patients who had no evidence of recurrence or
metastasis. Neither familial
myxoma nor
Carney complex was found. The 5 cases of
myxosarcoma and 18 randomly selected cases of
myxoma were evaluated for proliferative activity, metastatic potential, and
oncogene products by immunohistochemistry. The expression of p53 and Bcl-2 was similar in both groups. Overexpression of
proliferating cell nuclear antigen and low expression of nm23 in
myxosarcoma are consistent with the high rate of recurrence and
metastasis of this
tumor. Surgical resection of sporadic
myxoma is a safe and effective treatment with satisfactory early and long-term results. However, the prognosis of
myxosarcoma is still disappointing. Regular echocardiography and chest radiography or computed tomography are necessary for early detection of recurrence or
metastasis of
myxosarcoma.