Involvement of the central nervous system is the most clinically important manifestation of cysticercosis, but encystment of larvae can occur in almost any tissue, including the eye, lung, skeletal muscle, liver, kidney, subcutaneous tissue, and even the heart. We report a case of an incidental finding of isolated subendocardial cysticercosis in a young man native to Cameroon. The published literature on cardiac cysticercosis is reviewed.
A 17-year-old male with a 2-year history of hypertension medically managed with hydrochlorothiazide and felodipine was referred to a cardiologist for possible left ventricular hypertrophy. The cardiac examination and electrocardiogram were normal, but during screening transthoracic echocardiography a nonobstructing cyst adhering to the interventricular septum in the left ventricular outflow tract was noted. The echocardiogram was otherwise normal.
An initial review of the literature revealed hundreds of similar appearing cases of intracardiac echinococcal hydatid cysts. Although the patient's family had lived in a rural West African village and depended on subsistence crops, he denied exposure to canines, cattle, sheep, horses, and pigs, but admitted to eating undercooked pork on multiple occasions during the 15 years he spent near Buea, Cameroon. Additional travel history included the 2 years he spent in rural southern Germany while accompanying his older brother during a U.S. military assignment.
At time of presentation to our clinic, the patient denied fever, headache, chronic cough, chest pain, dyspnea, abdominal pain, visual disturbances, jaundice, night sweats, or weight loss. Laboratory studies to include complete blood count, liver function tests, creatinine kinase, and serology for Echinococcus and Cysticercus by both enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunoelectrotransfer blot (EITB) were unremarkable and/or negative. Peripheral eosinophilia was absent. Cardiac magnetic resonance imaging (MRI) with contrast was performed to further evaluate the cystic lesion (Fig. 1). The MRI showed a solitary, well-circumscribed, oval, fluid-filled mass measuring 10 × 15 mm attached to the endocardial surface of the anteroseptal wall within the left ventricular outflow tract. The mass itself did not move significantly within the left ventricle during the cardiac cycle. Cine MR demonstrated normal left ventricle wall motion with a normal fractional shortening of 47%. Further imaging, including plain radiographs of the extremities and computed tomography (CT) of the head, chest, abdomen, and pelvis, did not demonstrate any additional cysts.
Although the dimensions were relatively small for a hydatid cyst, it was speculated that it was recently acquired and discovered before development of symptoms. As the location of the cyst appeared favorable for safe removal, it was agreed that the mass should be surgically resected to avoid the grave sequelae of a possible cyst rupture or embolization. Within 4 weeks of the initial echocardiogram, the patient underwent surgery with cardiopulmonary bypass. The cystic mass, located 2 cm from the aortic annulus and embedded underneath a thin layer of endocardium, was approached through a transverse aortotomy and excised without disruption of the cyst wall.
The patient's postoperative course was uneventful and he completed a 1-month course of albendazole. A follow-up echocardiogram 1 month later was normal and his essential hypertension was well controlled with metoprolol. Examination of the multiloculated, serous fluid-containing cystic structure unexpectedly revealed a larval cestode with surface microvilli, calcareous corpuscles, and a single scolex diagnostic of a T. solium cysticercus (Fig. 1).
Isolated cardiac cysticercosis is a rare finding and making the diagnosis proved to be challenging in the face of negative serology. Although previous neurocysticercosis epidemiologic studies report the immunoblot's (EITB) sensitivity to be greater than 90%, it has also been shown that sensitivity may decrease to 28–83% when only a single parenchymal cyst is involved.1 Identifying a scolex on MRI as in this case may thus serve as a useful tool in differentiating cysticercosis from other cardiac masses.
We conducted a MEDLINE search and found 23 published cases of cardiac cysticercosis from 1962 through 2006. The mean age at time of diagnosis was 37 years (range, 5–75) and the majority of cases were male (57%). Affected individuals originated from India (6), Mexico (3), Brazil (3), Russia (3), China (2), Zimbabwe (2), Burkina Faso (1), Macedonia (1), Honduras (1), and Haiti (1). All but 6 cases involved multiple cardiac cysts, and all but 4 had concomitant neurocysticercosis.
Fourteen of the 23 cases were discovered as an incidental finding at autopsy or during unrelated cardiac surgery.2–13 Collectively, gross examination revealed single to numerous cysts 2–30 mm in diameter randomly distributed in the subpericardium, epicardium, subendocardium, or myocardium of the atria, ventricles, septum, or papillary muscles. One autopsy documented as many as 43 such cysts.4 On cut surface, the cysts had clear to milky-white fluid and contained a thin white 1–2 mm knob-like prominence. Microscopic examination of this nodule demonstrated an invaginated scolex. With 1 exception,11 the principle cause of death in these 14 cases was unrelated to the presence of cysticerci within the heart.
With the advent and availability of improved imaging modalities to include echocardiography, CT, and MRI, more cases of cardiac cysticercosis are being diagnosed antemortem.14–21 Findings on echocardiogram range from solitary to numerous cysts with varying degrees of calcification.14–17 Niakara et al14 were able to demonstrate on echocardiogram multiple cysts in different stages of evolution within the same patient: hypodense areas representing early viable cysts and those with rims of calcification signifying older degenerating cysts. These patterns were no longer visible 10 months after a course of albendazole. A scolex could also be visualized on the initial echocardiogram, appearing as a small hyperdensity in the center of a larger hypodensity. The echocardiogram from our patient had a similar appearance. Cheung et al18 demonstrated that MR could detect additional noncalcified lesions not present on CT in a case of disseminated cysticercosis. Although MR imaging of our patient's left femur, spine, and brain did not reveal tissue-embedded cysticerci, the scans were not performed until at least 8 weeks after completing treatment with albendazole.
Cardiac cysticercosis is predominantly a silent disease, yet we found 6 cases in whom heart function was adversely affected. Dediunina19 described a young woman with disseminated cysticercosis and symptomatic bradycardia who had evidence of complete atrioventricular block and atrial fibrillation on EKG. Sun et al22 reported a case of disseminated cysticercosis involving heart block in which the patient's heart rate of 32 bpm failed to improve despite treatment with praziquantel. Prabhakar et al11 concluded that cysticercosis-induced arrhythmia was the cause for sudden death in a previously healthy 45-year-old man with autopsy findings of numerous myocardial cysts. Recently there have been 2 case reports of patients with histories of neurocysticercosis who presented with progressive dyspnea and peripheral edema caused by congestive heart failure. In each instance, diffuse and widespread myocardial calcification secondary to numerous degenerating cysticerci resulted in either restrictive cardiomyopathy and/or conduction abnormalities.16,17 Both patients improved, including 1 medically managed without an antihelminthic agent. The most serious sequelae from cardiac cysticercosis, however, are described in a 33-year-old patient with pleural and pericardial effusions who was scheduled for heart surgery because of severe tricuspid stenosis and a large apical filling defect on cardiac catheterization. While on cardiopulmonary bypass, large cysts were removed from the left ventricle, inferior vena cava, from around the tricuspid valve, and from a near completely obstructed pulmonary artery.21
Although fewer than 25 cases have been described in the medical literature, cardiac cysticercosis is not as rare as what has been reported. As early as 1944, Dixon and Hargreaves23 found that 45 of 284 cases (15.8%) of human cysticercosis involved the heart at autopsy. More recent studies from Brazil that retrospectively reviewed autopsy reports reaffirmed that the intracardiac form of cysticercosis is not uncommon. Costa-Cruz et al24 reviewed 2862 reports and found 39 cases of cysticercosis, 9 (23.1%) of which involved the heart. Lino et al25 and Vianna et al26 reported rates of 22.6% and 8.0%, respectively. Even still, our case of cardiac cysticercosis was unusual in that the infection was limited to a single lesion. We could find only 4 other published cases documenting the heart as the sole involved organ, all of which were discovered at autopsy;6,8,9,11 and of those, only 1 describes the presence of a single cardiac cyst.8
The authors thank Dr. Patrick Malafronte for histology services, Drs. Matt Monson and Vincent Ho for radiographic interpretation, and Drs. Cade Nylund and Boris Gafurov for their assistance in translating selected case reports.
1. Garcia HH, Gonzalez AE, Evans CA, Gilman RH. Taenia solium
2. Khelimskii AM. Cysticercosis of the brain, heart and skeletal muscles. Med Parazitol (Mosk)
3. Reddy DJ, Raghavchar V, Saran BM, Vasantha VC. Cysticercosis in Guntur. J Indian Med Assoc
4. Goldsmid JM. Two unusual cases of cysticercosis in man in Rhodesia. J Helminthol
5. Ibarra-Perez C, Fernandez-Diez J, Rodriguez-Trujillo F. Myocardial cysticercosis: report of two cases with coexisting heart disease. South Med J
6. Saxena H, Samuel KC, Singh B. Cysticercosis of the heart. Indian Heart J
7. Miramedov GS, Mukhorin BP, Artemenko VV. Cysticercosis lesion of the brain, meninges, heart and diaphragm. Arkh Patol
8. Deshpande VL, Patil SD. Silent myocardial cysticercosis. Indian Heart J
9. Belagavi CS, Goravalingappa JP. Cysticercosis of the heart. A case report. Indian Heart J
10. Grozdev LJ, Kaftandziev D, Roganovic D, Colanceski V. Pathomorphologic and ultrastructural characteristics of endocardial Cysticercus cellulosae. Acta Chir Iugosl
11. Prabhakar BR, Manjari M, Vadehra PL. Cardiac cysticercosis. Indian J Pathol Microbiol
12. Rosha D, Panda BN. Disseminated cysticercosis. J Assoc Physicians India
13. Mauad T, Battlehner CN, Bedrikow CL, Capelozzi VL, Saldiva PH. Case report: massive cardiopulmonary cysticercosis in a leukemic patient. Pathol Res Pract
14. Niakara A, Cisse R, Traore A, Niamba PA, Barro F, Kabore J. Myocardial localization of a disseminated cysticercosis. Echocardiographic diagnosis of a case. Arch Mal Coeur Vaiss
15. Sousa Ade Q, Solon FR, da Costa Filho JE, Lima FH. Disseminated cysticercosis with asymptomatic involvement of the heart. Braz J Infect Dis
16. Blandon R, Leandro IM. Human cardiac cysticercosis. Rev Med Panama
17. Melo RM, Melo Neto AV, Correa LC, Melo Filho AV. Restrictive cardiomyopathy due to myocardial cysticercosis. Ar Qbras Cardiol.
18. Cheung YY, Steinbaum S, Yuh WT, Chiu L. MR findings in extracranial cysticercosis. J Comput Assist Tomogr
19. Dediunina RS. Case of cysticercosis of the skeletal muscles and internal organs. Klin Med (Mosk)
20. Cutrone JA, Georgiou D, Gil-Gomez K, Brundage BH. Myocardial cysticercosis detected by ultrafast CT. Chest
21. Robinson RJ, Truong DT, Mulder D, Digerness SB, Kirklin JK. Case 1989–3. A 33-year-old woman develops a “stone heart” and is successfully treated with magnesium. J Cardiothorac Anesth
22. Sun RL, Wang FZ, Hu SJ. Intra-hisian block associated with unusual etiologies. Pacing Clin Electrophysiol
23. Dixon HBF, Hargreaves WH. Cysticercosis: A further 10-year clinical study covering 284 cases. Q J Med
24. Costa-Cruz JM, Rocha A, Silva AM, et al. Occurrence of cysticercosis in autopsies performed in Uberlandia, Minas Gerais, Brazil. Ar Qneuropsiquiatr
25. Lino RS Jr, Reis MA, Teixeira VP. Occurrence of encephalic and cardiac cysticercosis (Cysticercus cellulosae) in necropsy. Rev Saude Publica
26. Vianna LG, Macedo V, Costa JM. Musculocutaneous and visceral cysticercosis: a rare disease? Rev Inst Med Trop Sao Paulo