Fast growing angiosarcoma of the right atrium after radiofrequency catheter ablation: a missed diagnosis or misdiagnosis case report

Abstract

Background: Primary angiosarcomas of the right atrium are extremely rare, often resulted in missed diagnosis or misdiagnosis with routine examination tools. These malignant cardiac tumors are highly aggressive with generally poor prognosis. Surgical excision is the mainstay of treatment as it is essentially not responsive to current regimens of chemoradiotherapy.

Case presentation: Herein, we describe a patient who initially presented with paroxysmal atrial fibrillation and was subsequently treated with radiofrequency catheter ablation (RFCA). Prior to RFCA, an initial transesophageal echocardiography revealed a local thickening of the intratrial septum. Three months later, she was hospitalized with progressive dyspnea and massive pericardial effusion. A large immobile, non-pedunculated mass, occupying almost half of the right atrium was detected by transthoracic and transesophageal echocardiogram. Multimodality cardiac imaging was useful in further characterizing this mass, which was ultimately diagnosed as an angiosarcoma based upon biopsy results. The growth rate was extremely rapid following RFCA, and patient underwent surgical excision. After discharge, the angiosarcoma recurred and patient survived for 7 months from the first episode of tamponade.

Conclusions: Primary cardiac angiosarcoma of the right atrium can easily be mistaken for structural anomalies in its early stages, losing the opportunity for initiating earlier treatments to improve potential patient outcomes. The correct diagnosis of this rare case relied on the comprehensive utilization of multimodal imaging techniques including biopsy.

Keywords: Cardiac imaging; Cardiac tumor.

Fig. 1

Echocardiography revealed the changes of the mass before and after RFCA. a Before RFCA, transesophageal echocardiography (TEE) revealed a local thickening of the interatrial septum (*) near the root of aorta. b Transthoracic echocardiography (TTE) detected a large immobile, non-pedunculated mass (*) involving the interatrial septum 3 months after RFCA. c TEE revealed a large polymorphic tumor (*) infiltrating the right atrial walls with hypoechoic area (arrow) 3 months after RFCA

Fig. 2

PET-CT assessed the metabolic activity of the cardiac mass. a Positron emission tomography scan showed hypermetabolic activity (*) in the RA with a standard uptake value SUV_max of 21.2. b 18F-FDG PET-CT fusion image illustrates high FDG uptake of the cardiac mass (*). 18F-FDG PET-CT: F18-fluorodeoxy glucose-positron emission tomography

Fig. 3

Pathological analysis identified the tumor as a primary cardiac angiosarcoma. a Malignant cells are frankly atypical with hyperchromatic nuclei (arrow). They line poorly formed immature vessels containing red blood cells (H&E stain). b Immunohistochemical stain for CD31 (blue) revealed the endothelial nature of the tumor cells (original magnification × 200)