Intramyocardial hydatid cyst: a case report.

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A 52-year-old female patient presented with complaints of increasing retrosternal chest discomfort and dyspnoea on exertion since 3 months. Her physical examination was unremarkable. On evaluation, the heart rate, rhythm, and jugular venous pressure were normal. Auscultation findings were also unremarkable. Haematological and biochemical parameters were within normal limits. Electrocardiography (ECG) revealed no abnormal findings. X-ray and echocardiography were advised for routine workup following which cardiac magnetic resonance imaging (MRI) was advised for detailed evaluation. The posteroanterior chest X-ray revealed a well-defined, lobulated, homogenous radiopaque lesion in left paracardiac mid-zone silhouetting with left heart border. Parasternal long-axis view on echocardiography showed multiseptated anechoic lesion adjacent to left ventricle causing luminal compromise suggestive of hydatid cyst likely within the interventricular septum and left ventricular wall (Figure , Supplementary material online, ). Short-axis view on echocardiography showed multiseptate anechoic lesion arising from left ventricular wall suggestive of intramyocardial hydatid cyst (Supplementary material online, ). Apical view on echocardiography of the four chambers of the heart showed hydatid cyst arising from interventricular septum, and left ventricular wall causing narrowing of left ventricular lumen (Supplementary material online, ). Two-dimensional echocardiography showed multiple echo free cystic spaces around pericardium compressing right and left ventricles. Pre-contrast T1- and T2-weighted black blood images on cardiac MRI showed large multivesicular and septated, cystic (T2 hyperintense) lesion with water content (low signal on T1; high signal on T2) in the interventricular septum extending into anterior wall (giving wheel like appearance) suggesting intramyocardial hydatid cyst (Figure, Supplementary material online, ). The patient was taken up for cardiac surgery and after successful excision is now following up on albendazole treatment. Pathology of the resected specimen (hydatid cyst) showed laminated membrane on 10× and 40× haematoxylin and eosin magnification (Supplementary material online and ). Post-operative chest X-ray showed resolution of lesion. The patient was asymptomatic in the 7-month follow-up period following surgery.

Figure 1

Parasternal long axis view on echocardiography showed multiseptated anechoic lesion adjacent to left ventricle causing luminal compromise suggestive of hydatid cyst likely within the interventricular septum and left ventricular wall.

Figure 2

Pre-contrast T1 and T2 weighted black blood images on cardiac MRI showed large multivesicular and septated, cystic (T2 hyperintense) lesion with water content (low signal on T1; high signal on T2) in the interventricular septum extending into anterior wall (giving wheel like appearance) suggesting intramyocardial hydatid cyst.

Discussion

The incidence of human cystic echinococcosis is 1.6 per 100 000 worldwide with hyperendemic areas registering up to 50 cases per 100 000. Symptoms may include pericardial pain, dyspnoea, and cardiac arrhythmia in rare instances or may even present as acute coronary syndrome. Conventional echocardiography is the diagnostic tool of choice because of high sensitivity for intracardiac hydatid cysts; however, it might appear sometimes as a tumour-like mass on echocardiography when multiseptate., Treatment includes complete excision of the cyst because of associated complications like cyst rupture and sudden death, even in asymptomatic patients., It is emphasized that hydatid cyst should be considered as a differential of all cystic masses in all anatomical locations including rare sites like myocardium, especially in endemic areas.

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