Unusual large mass on aortic valve in an infant

ABSTRACT

Mass on the aortic valve is extremely rare in children, and the differential diagnosis includes vegetation, thrombus, and primary cardiac tumors. A rise in infective endocarditis in infants is seen due to increasing survival of children with congenital heart diseases and sick newborn infants with prolonged hospitalization. We report a 4-month-old infant born prematurely with early-onset sepsis requiring prolonged antibiotic treatment and valvular aortic stenosis presenting with sudden hemodynamic compromise due to aortic vegetation extending into the ascending aorta eroding through its posterior wall. The report details management of our case and a brief description of available alternative treatment strategies.

INTRODUCTION

The occurrence of an aortic mass in an infant is a rare event. In the presence of underlying valve pathology, the likelihood of a thrombus or vegetation is increased. Fungal endocarditis constitutes one-eighth of all pediatric infective endocarditis cases. About two-thirds of these cases occur in children <1 year of age. Despite medical and surgical management, the disease carries a high mortality and morbidity rate. We hereby report a case of an infant with valvular aortic stenosis with fungal endocarditis presenting as an aortic mass. The report also details the management of the case and available alternate strategies.

CLINICAL SUMMARY

A 4-month-old infant presented with respiratory distress and refusal to feed of 3-day duration. The child was born preterm at 31 weeks with delayed cry at birth requiring mechanical ventilation. During the neonatal admission, which lasted for a total of 33 days, the child had early-onset neonatal sepsis requiring broad-spectrum antibiotics for 4 weeks. The infant also received antifungal medications for 1 week. The child was readmitted following neonatal discharge for evaluation of seizures, which revealed periventricular leukomalacia. The child was detected to have bicuspid aortic valve with severe valvular aortic stenosis. The peak instantaneous gradient was 64 mmHg and the mean gradient was 42 mmHg with normal left ventricular function. In view of low weight (1.9 kg) and normal cardiac function, close follow-up was planned for the child. One month before the present admission, the child developed bullous lesions containing clear fluid over the left arm. The clinical impression was suggestive of irritant contact dermatitis. Needle aspiration was performed, and local desonide application was advised. The child developed honey-colored crusts over these lesions 2 weeks later.

On examination, the child looked emaciated and irritable. The heart rate was 157/min, and the child was tachypneic with intercostal and subcostal retractions. The child was pale but had no cyanosis, clubbing, lymphadenopathy, or icterus. The first heart sound was unremarkable with soft second heart sound. The aortic component was softer than the pulmonary component. An ejection systolic murmur Grade III/VI was heard along the right upper sternal border over the aortic area. The liver was palpable 2.5 cm below the right costal margin in the midclavicular line, and crepitations were heard over both the lung fields. The chest radiograph revealed cardiomegaly with a cardiothoracic ratio of 0.7, with features suggestive of mild pulmonary venous hypertension. Echocardiography revealed a large 2.0 cm × 1.4 cm hyperechoic mass in the ascending aorta attached to the anterior leaflet of the bicuspid aortic valve extending posterior and involving the posterior wall of the aorta [Figure 1]. Superiorly, the mass extended up to the origin of the innominate artery. There was large circumferential pericardial effusion with no evidence of tamponade. The peak and mean gradient obtained across the aortic valve were 35 and 24 mmHg, respectively. There was moderate left ventricular systolic dysfunction. Considering the clinical condition of the child, he underwent computed tomographic angiography (CTA) instead of magnetic resonance imaging for further delineation of the mass and defining its anatomical extent for surgical planning [Figure 2]. CTA depicted a large nonenhancing intraluminal lobulated mass lesion within the aortic root and ascending aorta measuring 1.6 cm × 1.0 cm × 1.8 cm with an exophytic component. The exophytic component of the mass extended into aortopulmonary window and showed loss of fat planes with the main and right pulmonary artery. There was associated thickening of one of the aortic valve leaflets, which was contiguous with the intraluminal mass [Figure 2]. The child underwent an emergency cardiac surgery consisting of intra-aortic vegetectomy with posterior aortic wall reconstruction with autologous unfixed pericardium and aortic homograft. However, the child expired in the immediate postoperative period. The histopathology of the mass revealed necroinflammatory exudate along with numerous fungal balls morphologically resembling yeast and pseudohyphal forms of Candida. The culture of the mass grew Candida tropicalis.

Figure 1.

(a) The hyperechoic homogenous lesion measuring 1.88 cm × 1.4 cm imaged in the ascending aorta in the modified short-axis view. (b) The vertical extent of the mass shown extending up to the origin of the innominate artery. (c) The parasternal long-axis view demonstrating the attachment of the anterior leaflet (arrow) of the bicuspid aortic leaflet to the mass

Figure 2.

(a and b) Axial and oblique coronal multiplanar reformatted images and volume-rendered image. (c) A large nonenhancing intraluminal lobulated mass lesion (indicated by *) extending from the thickened aortic valve leaflet (black arrow in 2b) to the ascending aorta. The exophytic component of the mass shows loss of fat planes with the main pulmonary artery (p) and RPA. RPA: Right pulmonary artery, (RV: right ventricle; LV: left ventricle)

DISCUSSION

Mass on the aortic valve is extremely rare, and the differential diagnosis includes vegetation, thrombus, and primary cardiac tumors. The anatomical variant is Lambl’s excrescences, which are limited to the elderly. In the neonatal population, symptomatic aortic thrombosis has an incidence of 0.1–1.1/100,000 newborns. The clinical presentation in neonates is variable and ranges from nonspecific irritability to embolic complications such as stroke, acute limb-threatening ischemia, mesenteric ischemia, and renal failure. Majority (80%) of cases are associated with umbilical artery catheterization, but other risk factors include sepsis, extreme prematurity, and prothrombotic conditions.[1] Papillary fibroelastoma is a primary cardiac tumor with predilection for valvular endocardium. It primarily affects the elderly, with only a few cases reported in children.[2,3,4,5] With increasing survival of children with congenital heart diseases and sick newborn infants with prolonged hospitalization, a rise in infective endocarditis has been noted. Any lesion associated with turbulence of flow, with or without shunting, can be a substrate for IE. Aortic valve disease was a common lesion in a series of children who developed IE and had no history of surgery.[6,7]

The reported frequency of fungal endocarditis in children is about 1.5–4/10 million children, and it constitutes up to 12% of all pediatric cases of infective endocarditis.[8,9] Around 63% of pediatric cases are described in neonates and infants younger than 1 year.[8] Various risk factors have been identified for developing fungal endocarditis, with premature neonates and children with congenital heart defects forming the two main groups. Major risk factors in premature neonates include prolonged broad-spectrum antibiotics, indwelling central venous catheters, parenteral nutrition, and inherent immaturity of the immune function. The congenital heart defects requiring palliative or curative surgeries using grafts or prosthesis constitute another high-risk population. Native valve endocarditis due to altered milieu of blood flow and resultant jets also provides a fertile bed for circulating organisms. The incidence of fungal endocarditis is increasing due to greater detection and prevailing predisposing conditions. Among the various predisposing conditions, our child was born preterm, received prolonged broad-spectrum antibiotics, and had underlying cardiac disease.

The ascending aortic mass could be a vegetation, tumor, or thrombus. The absence of the mass in an echocardiogram performed few days prior made tumor unlikely. Moreover, the occurrence of impetigo in the intervening period providing the nidus for a staphylococcal dissemination favored the diagnosis of vegetation.

With lack of clear consensus guidelines on management of such cases, various treatment regimens have been used over the years. Amphotericin B, despite its poor vegetation penetration capacity, with or without added flucytosine remains the mainstay of medical management of fungal endocarditis. Various combinations of the newer antifungal agents such as caspofungin, echinocandins, and azoles have been tried in view of better safety profile.[10] Recently, recombinant tissue plasminogen activator has been used for resolution of the vegetations.[11,12,13,14] Cardiac surgery was considered in our patient because of its large size, location, and associated aortic stenosis causing hemodynamic compromise. Our case highlights the rapidity and lethality of fungal endocarditis. With improving perinatal care, the proportion of at-risk children is steadily rising. In the absence of established treatment guidelines, treatment modalities should be individualized.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

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Conflicts of interest

There are no conflicts of interest.