Multiparametric CMR Characterization of a Right Ventricular Apical Mass with an Incidental Paravertebral Lesion

Walid Zenini MD, Naziha Soltani MD, Thomas Hovasse MD, Jérôme Garot MD PhD 

Institut Cardiovasculaire Paris Sud, Department of Cardiovascular Imaging, Hôpital Privé Jacques Cartier, Ramsay Santé, Massy, France

Clinical History

A 70-year-old woman with a history of breast adenocarcinoma, receiving anthracycline-based cytotoxic chemotherapy, was referred for cardiovascular magnetic resonance (CMR) characterization of a cardiac mass. She was asymptomatic from a cardiovascular standpoint and had no clinical signs of heart failure. During routine transthoracic echocardiography (TTE) performed before the next chemotherapy cycle, a mass was incidentally identified at the right ventricular (RV) apex. In the setting of active malignancy, distinguishing thrombus from metastatic disease was clinically important because the two diagnoses would lead to different management. Comprehensive CMR was therefore performed for anatomic assessment and tissue characterization.

CMR Findings

CMR was performed on a 1.5-T MAGNETOM Sola scanner (Siemens Healthineers, Erlangen, Germany). The protocol included balanced steady-state free precession (bSSFP) cine imaging, T1 weighted (T1w) spin-echo imaging, T2 weighted (T2w) short-tau inversion recovery (STIR), first-pass gadolinium perfusion, and late gadolinium enhancement (LGE). T2 mapping and a dedicated post-contrast high-inversion-time sequence at approximately 600ms were not acquired.

CMR demonstrated an irregular, ill-defined solid mass measuring 42 × 23 mm, obliterating the RV apex and extending into the adjacent RV myocardium. Quantitative analysis showed a left ventricular ejection fraction (LVEF) of 56%, a right ventricular ejection fraction (RVEF) of 49%, a left ventricular end-diastolic volume index (LVEDVI) of 82 mL/m², and a right ventricular end-diastolic volume index (RVEDVI) of 72 mL/m². The index ventricular volumes were not reduced.

On four-chamber bSSFP cine imaging, the mass appeared as a fixed, irregular filling defect with lower signal than the blood pool, without a visible pedicle or independent mobility (Movie 1). The wide thoracic field of view also showed an incidental right paravertebral lesion in the background, which was more clearly delineated on an axial scout image (Figure 1). An RV three-chamber cine provided an additional view of the apical mass and its relationship to the RV myocardium (Movie 2).

Movie 1. Four-chamber bSSFP cine showing a fixed, ill-defined 42 × 23 mm mass obliterating the RV apex and extending into the RV myocardial wall (solid arrow). The incidental right paravertebral lesion is visible within the wider thoracic field of view (open arrow).

Figure 1. Axial scout/localizer image demonstrating the right paravertebral soft-tissue lesion adjacent to the thoracic vertebral column (open arrow).

Movie 2. RV three-chamber bSSFP cine providing an additional view of the RV apical mass and its relationship to the adjacent myocardium (arrow).

On T1w spin-echo images, the RV lesion was isointense to the adjacent myocardium, without intrinsic T1w hyperintensity to suggest hemorrhagic content (Figure 2). On T2w STIR imaging, the RV mass was markedly and relatively homogeneously hyperintense, indicating increased tissue water content (Figure 3). The right paravertebral lesion was also hyperintense on the wide-field four-chamber image (Figure 3). Four-chamber first-pass perfusion demonstrated early internal gadolinium enhancement within both the RV mass and the right paravertebral lesion. Enhancement of the RV mass favored vascularized tissue over an avascular thrombus (Movie 3). LGE imaging demonstrated dense heterogeneous enhancement of the RV apical mass with central hypointense areas. The right paravertebral lesion also showed heterogeneous enhancement (Figure 4).

Figure 2. T1w spin-echo images in the RV long-axis/outflow tract (A) and four-chamber (B) views. The RV apical mass is isointense to the adjacent myocardium (solid arrows). The right paravertebral lesion is also isointense on the wide-field four-chamber image (open arrow).

Figure 3. T2w STIR images in the RV long-axis/outflow tract (A) and four-chamber (B) views. The RV apical mass is markedly hyperintense (solid arrows). A concomitant hyperintense right paravertebral lesion is visible on the wide-field four-chamber image (open arrow).

Movie 3. Four-chamber first-pass gadolinium perfusion showing early internal enhancement of the RV apical mass (solid arrow) and the right paravertebral lesion (open arrow).

Figure 4. Four-chamber LGE image demonstrating dense heterogeneous enhancement of the RV apical mass (solid arrow), with central hypointense areas. The right paravertebral lesion also shows heterogeneous enhancement (open arrow).

Conclusion

The multiparametric CMR appearance was most consistent with a RV apical metastatic lesion rather than thrombus, based on the infiltrative morphology, marked T2w hyperintensity, early internal first-pass enhancement, and heterogeneous LGE. The examination also identified an incidental paravertebral lesion suspicious for metastatic disease, prompting further oncologic assessment. Histologic confirmation of the cardiac lesion was not available. Subsequent positron emission tomography (PET) imaging confirmed metastatic disease and supported the CMR interpretation. The oncology team modified the patient’s management; details of the revised systemic regimen and later imaging follow-up were not available to the authors.

Perspective

Secondary cardiac involvement is more common than primary cardiac malignancy, and breast cancer is among the recognized sources of cardiac metastases in women.[1,3] The RV apex can be difficult to assess fully with TTE because of acoustic and geometric limitations. CMR is particularly useful in this setting because it combines morphology, ventricular function, tissue signal, perfusion, and post-contrast characterization in a single examination.[2]

In a patient with active malignancy, the principal practical question is often whether an intracardiac mass represents thrombus or neoplastic tissue. Morphology alone is not sufficient. In this case, the fixed infiltrative appearance raised concern for tumor, while marked T2w hyperintensity indicated increased tissue water. Early internal first-pass enhancement demonstrated vascularized tissue and made an avascular thrombus unlikely. Heterogeneous LGE provided further support for neoplastic tissue, although neither perfusion nor LGE is independently pathognomonic. Organized thrombi may occasionally show peripheral enhancement, and dedicated high-inversion-time imaging can provide additional information when available.[2,4]

The study by Chan et al. demonstrated the clinical value of LGE-CMR tissue characterization for differentiating cardiac neoplasm from thrombus in patients with systemic cancer and linked CMR-defined mass phenotype with outcomes.[4] In the present case, the concordant findings across cine imaging, T2w STIR, first-pass perfusion, and LGE supported a non-invasive working diagnosis of metastatic involvement. The paravertebral lesion showed the same multiparametric pattern as the RV mass: T1w isointensity, marked T2w STIR hyperintensity, early internal enhancement on first-pass perfusion, and heterogeneous LGE. This concordant appearance raised suspicion for synchronous neoplastic involvement but did not establish extracardiac staging by CMR alone. The finding instead prompted further oncologic evaluation, with subsequent PET imaging confirming metastatic disease.

Table 1. Sequence-by-sequence appearance of the RV apical mass and the incidental right paravertebral lesion. The table reports only directly observed findings and separates imaging appearance from diagnostic interpretation.

Click here to view the Cardiac MRI images for the case on CloudCMR

References

1. Bussani R, De-Giorgio F, Abbate A, Silvestri F. Cardiac metastases. J Clin Pathol. 2007;60(1):27–34.
2. Motwani M, Kidambi A, Herzog BA, Uddin A, Greenwood JP, Plein S. MR imaging of cardiac tumors and masses: a review of methods and clinical applications. Radiology. 2013;268(1):26–43.
3. Maleszewski JJ, Anavekar NS, Moynihan TJ, Klarich KW. Pathology, imaging, and treatment of cardiac tumours. Nat Rev Cardiol. 2017;14(9):536–549.
4. Chan AT, Plodkowski AJ, Pun SC, et al. Prognostic utility of differential tissue characterization of cardiac neoplasm and thrombus via late gadolinium enhancement cardiovascular magnetic resonance among patients with advanced systemic cancer. J Cardiovasc Magn Reson. 2017;19:76. doi:10.1186/s12968-017-0390-2.

Case prepared by:
Erin Romberg, MD
Cases of SCMR, Editorial Board Member
Seattle Children’s Hospital
University of Washington