Cardiac myxoma and myxosarcoma: clinical experience and immunohistochemistry

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.