The Role of Multimodality Imaging in the Diagnosis and Follow-Up of Malignant Primary Cardiac Tumors: Myxofibrosarcoma-A Case Report and Literature Review

Abstract

Cardiac tumors are a very rare but heterogenous group of diseases that may reveal themselves through a variety of nonspecific cardiac symptoms that may pose a challenge to the diagnostic process. Myxofibrosarcoma is a particularly rare type of cardiac tumor that carries a poor prognosis, thus making accurate and timely diagnosis essential. A 61-year-old woman presented with fatigue and shortness of breath during mild exercise, symptoms that have progressively worsened during the previous year. Multimodality imaging consisting of transthoracic and transesophageal echocardiography (TTE and TEE), cardiac magnetic resonance (CMR), cardiac computer tomography (CCT), and fluorodeoxyglucose positron emission computer tomography (18F-FDG PET-CT) was used for the diagnosis and postoperative follow-up of a myxofibrosarcoma.

Keywords: cardiac tumors; multimodality imaging; myxofibrosarcoma.

Figure 1

Transthoracic echocardiography (TTE) showing: (a) a round intracardiac mass attached to the right ventricle outflow tract (RVOT) wall by a pedunculus (white arrow); (b) turbulent flow on Color Doppler caused by the tumor’s severe obstruction of the RVOT (white arrow).

Figure 2

TTE Continuous Wave Doppler showing severe RVOT obstruction.

Figure 3

Transesophageal echocardiography (TEE) confirming the location, size, and shape of the tumor (white arrow).

Figure 4

Cardiac CT showing the mass localization 3 mm anterior of the pulmonary valve (white arrow), occupying 80% of the RVOT.

Figure 5

Cardiac CT reconstruction showing tumor (white arrow) correspondence to the neighboring anatomical structures: (a) two chambers reconstruction; (b) four chambers reconstruction.

Figure 6

Cardiac MRI (CMR) showing the mass’ (white arrow): (a) high signal intensity on the fat suppressed T2 weighted sequence; (b) late contrast enhancement.

Figure 7

(a) Hematoxylin-Eosin staining showing mesenchymal proliferation composed of fasciculate and myxoid areas containing cells with elongated and stellate nuclei. (b) Immunohistochemistry staining with negative result for calretinin, thus infirming the initial myxoma diagnosis/lack of typical brown colored areas.

Figure 8

18F-FDG fluorodeoxyglucose (18F-FDG) PET-CT showing: (a) an encapsulated effusion adjacent to the right ventricle infundibulum (white circle) with minimum calcification, thin minimally active margins, and no other 18F-FDG fixation zones at this level; slight 18F-FDG fixation at the sternum level due to recent sternoraphy; (b) no distant metastases on the whole-body examination.