Recurrent cardiac hydatid cyst: a rare case of initial misdiagnosis and successful surgical management.

BACKGROUND

Cardiac hydatid cyst (CHC), caused by Echinococcus granulosus, is a rare condition, comprising approximately 0.5-2% of hydatid cases. Despite its rarity, CHC presents significant clinical challenges, including mechanical obstruction, valvular dysfunction, arrhythmias, and the risk of anaphylactic shock due to cyst rupture. Surgical resection remains the standard treatment, but non-adherence to post-operative albendazole therapy is a major cause of recurrence.

CASE PRESENTATION: We report a 43-year-old man from an endemic rural region with a history of pulmonary hydatid cyst surgery five years earlier, who had prematurely discontinued albendazole and was lost to follow-up. He presented with progressive exertional dyspnea and signs of right-sided heart failure, including peripheral edema and ascites. Transthoracic and transesophageal echocardiography demonstrated a mass-like structure in the right ventricle causing outflow obstruction, and the working preoperative diagnosis was double-chambered right ventricle (DCRV) due to prominent hypertrophied muscle bundles. No dedicated hydatid serology or advanced cross-sectional cardiac imaging (CT or MRI) was obtained before surgery, and the patient was referred for correction of presumed structural heart disease. Intraoperatively, a large, partially perforated cystic lesion arising from the interventricular septum and infundibulum of right ventricle extending toward the tricuspid annulus was unexpectedly encountered and identified as a hydatid cyst; the diagnosis was subsequently confirmed by histopathological examination of the excised specimen. The cyst was completely removed, tricuspid valve competence was restored, and the patient experienced marked clinical improvement, with re-initiation of albendazole therapy at discharge.

DISCUSSION: This case demonstrates how intracardiac hydatid cysts can masquerade as structural heart diseases such as DCRV, leading to initial diagnostic misinterpretation. In endemic areas, clinicians should maintain a high index of suspicion for parasitic etiology, particularly in patients with previous hydatid disease. Integration of clinical, laboratory, and multimodal imaging data is essential for accurate diagnosis and timely surgical management.

CONCLUSION

Our case emphasizes the need for strict adherence to anti-parasitic therapy to prevent recurrence and highlights the complexities of diagnosing and managing CHCs. The challenges of echocardiographic diagnosis further reinforce the necessity of comprehensive imaging approaches and multidisciplinary management for optimal patient outcomes.