RESUMO
INTRODUCTION: Primary malignant cardiac mesenchymoma tumors are rarely described in the medical literature, with only a few published cases. CASE PRESENTATION: We present a case of a primary malignant mesenchymoma in the left atrium extending to the left and right inferior pulmonary vein orifices, accompanied by mechanical obstruction of the mitral valve. The patient underwent surgical removal and radiotherapy. DISCUSSION: Cardiac tumors are categorized as primary and secondary tumors. Primary cardiac tumors are extremely rare, with a low incidence rate of 0.001-0.28 %. Primary malignant tumors constitute less than 25 % of them. Malignant mesenchymoma is considered the rarest of them. These tumors proliferate and may cause metastases, making them highly malignant with a poor prognosis, especially if accompanied by metastases or invasion of nearby tissues. CONCLUSION: The poor prognosis of cardiac mesenchymoma comes from the fact that it is aggressive and rapidly growing, which causes a rapid progression of mechanical symptoms and metastasis to nearby tissues, which makes it classified as a highly malignant tumor with a low survival rate. Surgical resection remains the mainstay of treatment, in addition to follow-up with chemotherapy or radiotherapy according to the grade of the disease, which was the case with our patient and the same as reported in previous literature. However, further research and case reports are needed better to understand the optimal management of this aggressive tumor.