Abstract
Background
Intracardiac blood cysts rarely persist into adulthood and may lose their typical echolucent appearance when chronically hemorrhagic and organized.
Case Summary
A 54-year-old woman presented with exertional dyspnea. Transthoracic echocardiography revealed a mobile left ventricular outflow tract (LVOT) mass (19 × 16 mm) causing severe dynamic obstruction (peak gradient 85 mm Hg) without a classic anechoic cavity. Three-dimensional transesophageal echocardiography demonstrated subvalvular chordal attachment. Multimodality imaging, including myocardial contrast echocardiography, cardiac computed tomography, and cardiac magnetic resonance, showed no enhancement, supporting an avascular benign cyst. Valve-sparing excision with mitral valve repair was performed. Histopathology confirmed a chronically organized blood cyst, with resolution of LVOT obstruction and symptoms.
Discussion
Atypical adult LVOT blood cysts may mimic tumors or vegetations; multimodality imaging can establish benignity and guide valve-preserving surgery.
Take-Home Message
Integrated multimodality imaging can establish benignity and support safe valve-sparing surgery in atypical LVOT cysts.
Key Words: blood cyst, cardiac magnetic resonance, left ventricular outflow tract obstruction, mitral valve repair, multimodality imaging, three-dimensional transesophageal echocardiography
Visual Summary
Intracardiac blood cysts rarely persist into adulthood. When located near the left ventricular outflow tract (LVOT), they may cause clinically significant dynamic obstruction requiring intervention. We report an adult patient with an atypical LVOT mass in whom multimodality imaging established subvalvular chordal attachment and avascularity, enabling valve-sparing excision with complete hemodynamic and symptomatic resolution.
History of Presentation
A 54-year-old woman presented with progressive exertional dyspnea for 3 months, worsening from NYHA functional class II to class III. She denied syncope, presyncope, palpitations, chest pain, or embolic symptoms. Physical examination revealed a grade 3/6 systolic murmur at the left sternal border. Laboratory testing was unremarkable. Electrocardiography demonstrated left ventricular hypertrophy.
Take-Home Messages
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Adult left ventricular outflow tract blood cysts may become heterogeneous and nonecholucent due to chronic hemorrhage and organization, mimicking solid tumors or vegetations.
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Multimodality imaging confirming attachment and avascularity can justify valve-sparing excision and help avoid unnecessary valve replacement.
Past Medical History
She had no history of hypertension, diabetes, or prior cardiac disease.
Differential Diagnosis
Differential diagnoses for a mobile LVOT mass included cardiac tumors, organized thrombus, vegetations, and rare congenital or cystic lesions. The absence of perfusion on multimodality imaging favored an avascular cyst and supported a valve-preserving strategy.
Investigations
Step 1: hemodynamic assessment
Transthoracic echocardiography (TTE) revealed a well-defined LVOT mass measuring approximately 19 × 16 mm, with systolic excursion causing severe dynamic obstruction (peak velocity 4.6 m/s; peak gradient 85 mm Hg) and moderate eccentric mitral regurgitation due to leaflet tethering (Figure 1, Video 1).
Figure 1.
Transthoracic Echocardiography
Parasternal and apical views demonstrate a mobile LVOT mass (A, B). Continuous-wave Doppler shows severe LVOT obstruction (C). Color Doppler reveals eccentric mitral regurgitation (D). LVOT = left ventricular outflow tract.
Step 2: anatomic definition
Three-dimensional transesophageal echocardiography (3D-TEE) demonstrated a well-encapsulated lesion attached to the subvalvular chordae of the anterior mitral leaflet and protruding into the LVOT. The capsule appeared intact, and internal echogenicity ranged from hypoechoic to anechoic with focal calcifications. The detailed anatomic definition of the subvalvular attachment was central to anticipating that valve-sparing excision was feasible (Figure 2, Videos 2 and 3).
Figure 2.
Transesophageal Echocardiography
Multiplanar and 3D-TEE demonstrate subvalvular chordal attachment with heterogeneous internal echogenicity and focal calcifications (A to D). 3D-TEE = three-dimensional transesophageal echocardiography.
Step 3: tissue characterization and vascular assessment
Multimodality imaging demonstrated no contrast enhancement, supporting an avascular benign cyst. Myocardial contrast echocardiography showed no perfusion (Figure 3). Cardiac computed tomography (CT) demonstrated a low-density LVOT mass with focal calcification and no enhancement (Figure 4).
Figure 3.
Myocardial Contrast Echocardiography
No contrast enhancement within the LVOT lesion (A, B). LVOT = left ventricular outflow tract.
Figure 4.
Cardiac Computed Tomography
Low-density LVOT filling defect with focal calcification and no enhancement (A, B). LVOT = left ventricular outflow tract.
Cardiac magnetic resonance (CMR) cine imaging confirmed a smooth, mobile mass oscillating with diastolic inflow. The lesion was not well visualized on T1-weighted sequences, appeared slightly hypointense on T2-weighted imaging, and showed no late gadolinium enhancement—findings consistent with a benign, nonvascularized cystic structure (Figure 5).
Figure 5.
Cardiac Magnetic Resonance
The mass is visualized along the LVOT (B, C). It is not well seen on T1-weighted imaging (A), appears slightly hypointense relative to myocardium on T2-weighted imaging (B), and demonstrates no late gadolinium enhancement (C), findings consistent with a benign, avascular cystic lesion. LVOT = left ventricular outflow tract.
Management
Valve-sparing excision with mitral valve repair was performed via median sternotomy with cardiopulmonary bypass (bypass time 81 minutes; aortic cross-clamp time 40 minutes). Intraoperatively, a thin-walled cyst attached to the subvalvular mitral chordae was excised en bloc with involved chordal tissue. Mitral valve repair was performed without leaflet resection using artificial chordae - 5-0 Gore-Tex suture (W.L. Gore & Associates, Flagstaff) anchored to the papillary muscle and the A2 free edge, followed by limited anterior leaflet repair with - 5-0 Prolene suture (Ethicon, Inc., Johnson & Johnson, Somerville). Saline testing confirmed competent valve function. No prosthetic valve replacement was required.
Pathology demonstrated a 2.0 × 2.0 cm endothelial-lined cyst with layered fibrin, red blood cells, and focal calcified debris consistent with a chronically organized intracardiac blood cyst (Figure 6). The postoperative course was uneventful, and the patient was discharged on postoperative day 11.
Figure 6.
Surgical and Histopathologic Findings
Gross examination reveals a thin-walled cyst measuring 2.0 × 2.0 cm containing dark blood with areas of organization and focal calcified plaques within the cyst contents (A, B). Low-power hematoxylin and eosin (H&E) staining shows a fibrous cyst wall lined by flattened endothelial cells (C). High-power H&E demonstrates layered fibrin and red blood cells within the cyst lumen, consistent with a chronically organized intracardiac blood cyst (D).
Outcome and Follow-Up
Early postoperative TTE on postoperative day 7 demonstrated normal mitral valve motion, complete resolution of LVOT obstruction, and no residual mass (Figure 7, Videos 4 and 5). At 1-, 3-, and 6-month follow-up visits, the patient remained asymptomatic (NYHA functional class I). Repeat TTE confirmed preserved mitral valve function and sustained relief of LVOT obstruction without recurrence.
Figure 7.
Early Postoperative Transthoracic Echocardiography (Postoperative Day 7)
Two-dimensional imaging shows a patent LVOT without residual mass (A). Color Doppler demonstrates no mitral regurgitation (B). Continuous-wave Doppler confirms normalized LVOT gradients (C). LVOT = left ventricular outflow tract.
Discussion
Intracardiac blood cysts are typically benign congenital lesions that regress during infancy; persistence into adulthood is uncommon.1,2 When located near the LVOT, even benign lesions can produce clinically significant dynamic obstruction.1,3 In chronic stages, repeated intracystic hemorrhage and organization may lead to heterogeneous internal echogenicity, focal calcification, and altered magnetic resonance imaging signal characteristics. As a result, the classic echolucent appearance may be obscured, and the lesion may mimic a solid tumor or vegetation.
Evaluation of cardiac masses remains diagnostically challenging and often requires a multiparametric, multimodality approach integrating echocardiography, CT, and CMR.4, 5, 6 In the present case, each modality provided complementary information that informed management. TTE established the hemodynamic urgency by demonstrating severe dynamic LVOT obstruction and associated mitral regurgitation due to subvalvular tethering. Three-dimensional TEE then defined the lesion's subvalvular chordal attachment and preserved valvular apparatus—information essential for anticipating that valve-sparing excision was feasible—while also revealing markedly heterogeneous internal architecture consistent with chronic hemorrhage and organization. Cardiac CT and myocardial contrast echocardiography demonstrated no internal contrast enhancement, supporting absent vascularity; CMR showed no late gadolinium enhancement, further favoring a benign, nonvascularized cystic lesion. The focal calcifications observed on CT and 3D-TEE corresponded to calcified debris identified on histopathology, linking imaging heterogeneity to chronic intracystic hemorrhage and organization.
Hemodynamically significant LVOT obstruction warrants surgical excision irrespective of benign histology.1 Valve-sparing removal is feasible when the point of attachment is clearly defined preoperatively, and the valve apparatus is structurally intact.7, 8, 9 This case highlights an imaging-to-surgery pathway in which multimodality imaging established morphology, attachment, and avascularity, enabling a valve-preserving operative strategy with durable clinical improvement and avoidance of unnecessary valve replacement.
Conclusions
Atypical LVOT blood cysts may mimic solid cardiac masses. Multimodality imaging that defines attachment and avascularity can enable confident diagnosis and safe valve-sparing excision with resolution of obstruction and symptoms.
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
Appendix
Visual Summary.
| Timeline | Events |
|---|---|
| Day 1 | A 54-year-old woman presented with newly progressive exertional dyspnea (NYHA functional class III). Physical examination: grade 3/6 systolic murmur at the left sternal border. Laboratory test results, including inflammatory markers and cardiac biomarkers, were unremarkable. ECG: left ventricular hypertrophy. |
| Day 2 | TTE: well-defined, encapsulated LVOT mass 19 × 16 mm with predominantly isoechoic echogenicity and focal anechoic areas. Severe dynamic LVOT obstruction (Vmax 4.6 m/s; peak gradient 85 mm Hg). Moderate eccentric MR due to subvalvular tethering. |
| Day 3 | Three-dimensional TEE: encapsulated lesion attached to subvalvular chordae of the anterior mitral leaflet, intermittently protruding into the LVOT; heterogeneous contents with focal calcifications → valve-sparing excision considered feasible. |
| Day 3-10 | MCE/CT/CMR: MCE showed no contrast enhancement within the lesion; CT showed a low-density lesion without contrast enhancement; CMR demonstrated no late gadolinium enhancement → benign avascular cyst favored. Multidisciplinary heart team recommended surgical excision given severe LVOT obstruction. |
| Day 11 (surgery) | Underwent median sternotomy with cardiopulmonary bypass. Intraoperative findings: thin-walled, pedunculated cyst attached to subvalvular mitral chordae near papillary muscle. En bloc excision performed with concomitant mitral valve repair (valve-sparing strategy; no prosthetic material). |
| Day 22 (postoperative day 11) | Postoperative course uneventful; discharged home on POD 11. Pathology: 2.0 × 2.0 cm thin-walled cyst containing dark blood with organization and focal calcified debris; endothelial-lined fibrous wall with layered fibrin/RBCs → chronically organized intracardiac blood cyst. |
| 1, 3, and 6 months | Follow-up: asymptomatic (NYHA functional class I). Repeat TTE: resolved LVOT obstruction, normal mitral valve function, and no recurrence. |
Appendix
Transthoracic Echocardiography Demonstrating a Left Ventricular Outflow Tract Mass Causing Severe Dynamic Obstruction
Two-Plane Transesophageal Echocardiography Showing a Cystic Mass Attached to the Subvalvular Chordae and Protruding Into the Left Ventricular Outflow Tract
Three-Dimensional Transesophageal Echocardiography With Color Doppler Demonstrating a Pedunculated Subvalvular Cyst and Systolic Flow Acceleration in the Left Ventricular Outflow Tract
Early Postoperative Transthoracic Echocardiography Showing a Patent Left Ventricular Outflow Tract Without Residual Obstruction
Postoperative Transthoracic Echocardiography With Color Doppler Demonstrating no Residual Mitral Regurgitation After Valve-Sparing Excision and Repair
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Associated Data
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Supplementary Materials
Transthoracic Echocardiography Demonstrating a Left Ventricular Outflow Tract Mass Causing Severe Dynamic Obstruction
Two-Plane Transesophageal Echocardiography Showing a Cystic Mass Attached to the Subvalvular Chordae and Protruding Into the Left Ventricular Outflow Tract
Three-Dimensional Transesophageal Echocardiography With Color Doppler Demonstrating a Pedunculated Subvalvular Cyst and Systolic Flow Acceleration in the Left Ventricular Outflow Tract
Early Postoperative Transthoracic Echocardiography Showing a Patent Left Ventricular Outflow Tract Without Residual Obstruction
Postoperative Transthoracic Echocardiography With Color Doppler Demonstrating no Residual Mitral Regurgitation After Valve-Sparing Excision and Repair