A Pseudo-Right Atrial Mass in Massive Pulmonary Embolism - A Case Report Highlighting Multimodality Imaging and Multidisciplinary Team Review

Sep 28, 2026

Transthoracic echocardiography often serves as the first-line imaging test for cardiac assessment, but limited tissue characterisation can lead to anatomical variants being mistaken for pathology. A 44-year-old man with acute dyspnoea after long-haul travel was found on CT pulmonary angiography to have massive bilateral pulmonary emboli without right ventricular strain and was treated with rivaroxaban. At three months, follow-up TTE suggested a right atrial mass and prompted a switch to warfarin. Six months later CMR showed no mass, yet one-year TTE again suggested a right atrial mass. Cardiac imaging MDT review concluded the finding represented epicardial fat in the imaging plane, and rivaroxaban was resumed for indefinite anticoagulation, avoiding unnecessary treatment changes and highlighting MDT-led multimodality imaging.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages7

Reading Time18 min

AccessFree to download

Abstract

Introduction

Case Presentation

Patient presentation and initial assessment

Imaging and treatment timeline

Review began 11/09/2025 Review ended 11/27/2025 Published 12/02/2025 © Copyright 2025 Gupta et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0. , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited. DOI: 10.7759/cureus.98329 Open Access Case Report A Pseudo-Right Atrial Mass in Massive Pulmonary Embolism: A Case Report Highlighting Multimodality Imaging and Multidisciplinary Team Review Mehak Gupta 1, Aaditya Kodamanchile 1, Louise Tamin 1 , Pavithralakshmi Venkatraghavan 2, Andrew Cole 1 1. Cardiology, University Hospitals of North Midlands NHS Trust, Stoke-on-Trent, GBR 2. Medicine, Hereford County Hospital, Hereford, GBR Corresponding author: Andrew Cole, [a.cole10@nhs.net](a.cole10@nhs.net) Abstract Transthoracic echocardiography (TTE) is often the first-line imaging modality in cardiac assessment due to its accessibility and rapid acquisition. However, compared with cardiac magnetic resonance (CMR), it offers limited tissue characterisation and may misinterpret anatomical variants as pathology. Consequently, multimodality imaging and multidisciplinary team (MDT) review are frequently required for accurate diagnosis. A 44-year-old man presented with acute dyspnoea following long-haul travel. Computerised tomography pulmonary angiography revealed massive bilateral pulmonary emboli without right ventricular strain, and he was treated with rivaroxaban 20 mg once a day. Three months later, follow-up TTE demonstrated a right atrial mass, reported as a possible thrombus, prompting anticoagulation change to warfarin. At six months, CMR showed no intracardiac mass. However, repeat TTE at one year again suggested a right atrial mass. A review during the cardiac imaging MDT concluded that the apparent “mass”represented epicardial fat entering the imaging plane. Rivaroxaban 20 mg once a day was reinstated for indefinite anticoagulation. This diagnostic pitfall led to an unnecessary switch to warfarin, highlighting how misinterpretation of anatomical variants can significantly alter clinical management. This case underscores the critical role of multimodality imaging and MDT review in the evaluation of intracardiac masses to prevent misdiagnosis and unnecessary treatment. Categories: Nuclear Medicine, Cardiology Keywords: direct oral anticoagulant therapy, mri cardiac, multidisciplinary teams, right atrial cardiac mass, transthoracic echocardiogram Introduction Intracardiac masses encompass a broad differential, including thrombi, benign and malignant tumours, and infective vegetations. Their diagnosis can be challenging, as both clinical presentation and imaging appearances may be non-specific [1] . Transthoracic echocardiography (TTE) remains the initial diagnostic tool of choice, but it has limitations in tissue characterisation and in differentiating normal anatomical variants from true pathology. Cardiac magnetic resonance (CMR) provides superior spatial resolution and tissue characterisation, making it invaluable when echocardiographic findings are equivocal [2] . Multimodality imaging combined with multidisciplinary team (MDT) interpretation is recognised as essential to achieve diagnostic accuracy and guide management. Epicardial fat is a frequent mimic of intracardiac masses and can often be misinterpreted. Correct interpretation is crucial, as misdiagnosis can lead to unnecessary therapies, invasive investigations, or inappropriate long-term treatment. Here, we present the case of a gentleman who had an incorrectly diagnosed atrial thrombus from TTE, leading to a change in anticoagulation therapy. Case Presentation A 44-year-old man presented with a four-day history of progressive dyspnoea following a recent long-haul flight. His medical history included recurrent iron deficiency anaemia, a provoked deep vein thrombosis in 2015, and a

FAQs

Why can a right atrial mass be misinterpreted on transthoracic echocardiography?

TTE has limited tissue characterisation, which can cause normal anatomical variants to mimic true intracardiac pathology. In this case, the apparent mass was later attributed to epicardial fat entering the imaging plane.

What imaging sequence was used to evaluate the patient’s suspected intracardiac mass?

Initial CT pulmonary angiography assessed pulmonary embolism severity, followed by serial cardiac imaging. Follow-up TTE raised concern for a right atrial mass, CMR showed no intracardiac mass at six months, and repeat TTE at one year again suggested a mass.

How did the multidisciplinary team review change management?

The cardiac imaging MDT concluded the “mass” represented epicardial fat rather than a thrombus. Rivaroxaban was reinstated for indefinite anticoagulation, correcting the unnecessary earlier switch to warfarin.

Sep 28, 2026

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