Hydatid Cyst of the Right Atrium With Hepatic and Pulmonary Involvement and Concomitant Pulmonary Embolism, Presenting With Massive Haemoptysis: A Case Report.

Hydatid cyst disease, caused by Echinococcus granulosus, primarily affects the liver and lungs, while cardiac involvement, especially the right atrium (RA), is extremely rare. We report the case of a 21-year-old woman who presented with massive haemoptysis and hypoxemia. Transthoracic echocardiography demonstrated a large multicystic mass occupying the RA cavity, adherent to the atrial wall and interatrial septum, strongly suggestive of a hydatid cyst. Chest computed tomography angiography confirmed multiple pulmonary cystic lesions, intravascular filling defects consistent with pulmonary embolism, and a large hepatic hydatid cyst (5 × 4 cm). Serological testing for echinococcosis was positive. The patient underwent successful surgical excision of the RA cyst and pulmonary embolectomy under cardiopulmonary bypass. This case illustrates the rare presentation of an RA hydatid cyst with multiorgan involvement and associated pulmonary embolism, emphasizing the critical role of comprehensive imaging and timely surgical intervention in the management of complex echinococcosis.