Case report: Metastatic myxoid liposarcoma arising from the right atrium extends as cardiac tamponade-A rare case of atrial oncology

Abstract

The reported incidence of liposarcomas in ~2,000 cases annually results in about 30% of myxoid liposarcomas. Cardiac myoxid liposarcomas are very rare; their presentation could be cardiac tamponade, due to direct compression of the tumor and/or pericardial effusion. In this report, we describe a patient who presented with pericardial effusion secondary to myoxid liposarcomas from the right atrium, an extremely rare presentation of liposarcomas in the heart. We also present non-invasive imaging through echocardiography, CECT thorax and FDG PET scans, followed by a CT-guided mass biopsy. Histopathology of the right atrial mass demonstrated myxoid liposarcoma positive for the S100 tumor marker.

Keywords: FDG (18F-fluorodeoxyglucose)-PET/CT; cardiac tamponade; cardiac tumor diagnosis; liposarcoma—diagnosis; right atrium (RA).

Figure 1

(A) Imaging modalities and approaches carried out for the diagnosis of cardiac tamponade. (B) Pericardiocentesis followed by 2D-Echocardiogram revealed a 5 x 4 cm sized mass adjacent to the right atrium. Yellow highlighted area locates the myxoid liposarcoma in the right atrium.

Figure 2

Lymph node characteristics in the right atrium. (A) CECT thorax revealing minimally enhancing mass lesion in the right atrial wall. (B) Multiple enlarged retroperitoneal lymph nodes. (C) Horizontal sections of FDG PET scan revealing mildly FDG avid hypodensity (5.8 × 5 cm, SUV max −3.40) along the lateral wall of the right atrium with mass effect over it. (D) Coronal section of FDG PET scan revealing mildly FDG avid mass over the lateral wall of the right atrium. (E) Enlarged FDG avid lymph nodes at perivascular, aortocaval, retrocaval, and bilateral common iliac and external iliac levels (F). Yellow highlighted area locates the myxoid liposarcoma in the right atrium. White arrows in (F) indicates metastasis in abdomen areas.

Figure 3

Histopathology observations in right atrial mass (A) biopsy collected from right atrial mass demonstrated signet-ring-shaped lipoblasts in mucoid matrix suggestive of myxoid liposarcoma. (B) The tumor cells are positive for the S100 tumor marker. (C) Schematic illustration of possible risk factors associated with myxoid liposarcomas in the right atrium.