Myxome de la petite valve mitrale: à propos d’un cas

Cardiac myxomas are the most common type of primary cardiac tumors. They mainly affect the interatrial septum and exceptionally the heart valves. Surgical excision remains the only therapeutic alternative. We here report the case of a 69-year old patient with no significant pathological history suffering from NYHA class II-III dyspnea associated with lipothymia. Transthoracic echocardiography showed a tight calcified aortic narrowing with aortic valve gradient of 58 mmHg. A sessile mass of 15mm diameter inserted into the posterolateral leaflet, without stenosis or mitral regurgitation evoking an atypical localization of myxomaor or fibroelastoma was detected at the level of the mitral valve. The examination was supplemented by ETO which confirmed the diagnosis of a mass involving the posterolateral leaflet. The patient underwent surgery via median sternotomy, under conventional extracorporeal circulation. Left atriotomy allowed to objectify a sessile mass of 15mm of diameter involving the auricular wall of the friable and easily cleavable posterolateral leaflet. Cauterization of the implant base via electric scalpel was then performed without any additional gesture on the posterolateral leaflet. Anatomopathologic analysis of the surgical specimen confirmed the diagnosis of myxoma. The patient also underwent aortic valve replacement with mechanical prosthesis. The postoperative course was uneventful. The patient was discharged on postoperative day 8. Cardiac myxoma involving the mitral leaflet is very rare. Surgical procedure attempting to resect the widest possible surgical margins remains the only therapeutic option to avoid the risk of recurrence.