Thrombotic cardiac apex hydatid cyst.

Hydatid cyst (HC) is an endemic infestation in the cattle-breading countries such as in Iran. The involvement of heart by HC is rare; however, nesting of larva in the left ventricular apex with subsequent rupture to the systemic circulation and thrombus formation in the remaining cyst cavity is an exceedingly rare phenomenon. A 45-year-old man referred to our emergency cardiac room with chest pain and a transthoracic echocardiography (TTE) that showed a cardiac apex cystic lesion. The differential diagnosis of a cystic tumor, a HC, or aneurysm in the apex of the left ventricular walls was considered and evaluated by TTE and magnetic resonance imaging. However, the thrombotic HC was confirmed at the surgery. The cyst with its thrombotic component was excised surgically by on-pump cardiac surgery. The postoperative period was uneventful and the patient was discharged to home and treated with a full course of Albendazole therapy for 4 weeks. Six-month follow-up with TTE revealed complete healing of the apex defect without recurrence of the cyst.