An Unusual Left Ventricular Apical Mass

Abstract

Left ventricular apical masses constitute a rare finding. Imaging properties together with the clinical history of the patient usually allow an etiologic definition. We report a challenging case of an ambiguous left ventricular apical mass of uncertain nature till histological examination. Points of interest were singular clinical history and echocardiographic findings, although not conclusive in hypothesis generating. Furthermore to the best of our knowledge, this is one of the rare attempt to excise a deep left ventricular mass with a mini-invasive surgical approach.

INTRODUCTION

Left ventricular masses constitute a rare echocardiographic finding in the general population. With careful attention to its location and morphology and appropriate application of clinical information, echocardiography can usually distinguish between the three principal intracardiac mass lesions: tumor, thrombus and vegetation.[1] We report a challenging case of an ambiguous left ventricular apical mass of uncertain nature till histological examination. The anomaly was discovered during an echocardiographic evaluation done because of a recent cerebrovascular ischemic event.

CASE REPORT

A 67-year-old male presented to the emergency room because of a transient confusion episode one week before. He had a silent past personal medical history. Physical examination was negligible, whilst the electrocardiogram showed the presence of atrial fibrillation and T wave inversion in V3-V6 leads. Non-contrast-enhanced computed tomography (CT) scanning of the brain detected a hypodense area within left insular cortex. Doppler echography of supra-aortic arteries was unremarkable. Transthoracic echocardiogram demonstrated a 18 × 10 mm oval-shaped, homogeneous, echo dense, highly mobile mass floating in left ventricular apex [Figure 1a and b]. Concomitant findings were dilated left atrium without a significant mitral regurgitation, and dilated left ventricle with severely depressed global function (EF = 25%) in presence of akinetic apex. The intracardiac mass was characterized by pronounced mobility, lack of an identifiable peduncle (thus supposed to be faint), regular borders without capsule and homogeneous texture similar to myocardium (closer to the texture of vascularized tissues than to that of fibrotic or thrombotic structures). Coronary angiography showed no significant stenosis. Cardiac magnetic resonance imaging (MRI) excluded contrast enhancement of the mass, anyway its accuracy was limited by reduced temporal resolution in presence of atrial fibrillation and pronounced mass mobility. Owing to the embolic risk and the unaltered aspect after seven days of anticoagulant therapy, the patient underwent successful surgical excision through a video assisted Port Access approach [Figure 1c and d].

Figure 1.

(a) Apical four chamber view. (b) Parasternal short axis view at the apical level. (c) Trans-mitral mass view deep in left ventricular apex through right thorax HeartPort approach. (d) Excised white apical mass with its narrow stalk

Histopathologic examination identified organized hematic material configuring a white thrombus. Recovery was rapid and uncomplicated, optimal medical treatment for heart failure together with oral anticoagulant therapy was administered and well tolerated. Pre-discharge control echocardiography on the sixth day revealed a mild recovery in left ventricular function with a 35% ejection fraction, in the absence of apical thrombus recurrence.

DISCUSSION

According to the literature left ventricular apex is a rare site of origin for cardiac tumors, whilst it is most commonly involved in thrombotic stratifications of established cardiomyopathy.[1] Confounding elements in the exposed scenario came both from imaging properties of the mass, as from the clinical history of the patient who presented completely asymptomatic from a cardiological standpoint. Myxoma is the most common cardiac neoplasm, but it usually arises from interatrial septum presenting with heterogeneous echo-density. Fibroelastoma predominantly involves papillary muscles and cardiac valves, with shimmering edges. Fibroma is generally diagnosed in infants and young adults as a ventricular intramural mass.

High embolic risk and lack of an etiologic diagnosis imposed resection, anyway left ventricle severe contractile dysfunction conferred a high risk profile for a traditional surgical excision through ventriculotomy.[2] The combination of endoscopic views to Port Access allowed deep transmitralic thrombus visualization and its gentle pull for estraction.[3] Histopathologic examination identified organized hematic material configuring a white thrombus. The mechanism proposed to account for its development is segmental akinesia of sub-acute subendocardial infarction due to coronary embolization in the context of silent atrial fibrillation in idiopathic cardiomyopathy.[4]