Journal of Clinical Neonatology

CASE REPORT
Year
: 2015  |  Volume : 4  |  Issue : 2  |  Page : 123--125

Neonatal cardiac rhabdomyoma: An unusual presentation


Rajiv Balan, Ruchi N Nanavati, Nandkishor S Kabra 
 Department of Neonatology, Seth GS Medical College and KEM Hospital, Acharya Donde Marg, Parel, Mumbai, Maharashtra, India

Correspondence Address:
Dr. Nandkishor S Kabra
Department of Neonatology, Seth GS Medical College and KEM Hospital, Acharya Donde Marg, Parel, Mumbai - 400 012, Maharashtra
India

Abstract

Intracardiac tumors are very rarely seen in newborn infants. Rhabdomyoma is the most common primary cardiac tumor in infants. Rhabdomyoma is generally intramural and rarely causes cardiac outflow tract obstruction. Herewith we report an unusual presentation of cardiac rhabdomyoma arising from the free wall of the right ventricle.



How to cite this article:
Balan R, Nanavati RN, Kabra NS. Neonatal cardiac rhabdomyoma: An unusual presentation.J Clin Neonatol 2015;4:123-125


How to cite this URL:
Balan R, Nanavati RN, Kabra NS. Neonatal cardiac rhabdomyoma: An unusual presentation. J Clin Neonatol [serial online] 2015 [cited 2022 Dec 9 ];4:123-125
Available from: https://www.jcnonweb.com/text.asp?2015/4/2/123/154114


Full Text

 Introduction



Intracardiac tumors are very rarely seen in neonates and infants. Rhabdomyoma is the most common primary cardiac tumor in this age group, and accounts for about 60% of cardiac tumors. [1],[2] These tumors are generally intramural and rarely cause cardiac outflow tract obstruction. The left ventricle is the most frequently involved site. [3],[4] We describe an unusual presentation of cardiac rhabdomyoma arising from the free wall of the right ventricle and encasing the origin of the great vessels.

 Case Report



This male infant was born to a 21-year-old primi-gravida mother. There was history of third-degree consanguinity in the marriage. The infant was admitted to the neonatal intensive care unit with respiratory distress soon after birth. An antenatal scan performed at 35 weeks of gestation was suggestive of a large mediastinal mass (6 × 4 cm) in close relation to the pericardium anterior to the heart, displacing it to the left side and surrounded by a mild amount of free fluid. The Amniotic Fluid Index (AFI) was 26, suggestive of polyhydraminos. Ante-partum or intra-partum history was otherwise not significant.

This infant was born by normal vaginal delivery with vertex presentation. The infant required bag and mask ventilation for 30 s. Apgar scores at 1 and 5 min were 4 and 9, respectively, and the infant weighed 2.7 kg at birth. On physical examination, the infant's heart rate was 140/min and all peripheral pulses were equal and well felt. The capillary refill time was 3 s, The respiratory rate was 76/min with features of mild respiratory distress and the blood pressure was 86/64/72 mmHg. The apex beat was not well localized. Heart sounds were normal. There was no murmur. There were no signs of cardiac failure. Breath sounds were decreased bilaterally. Rest of the general physical examination was not contributory. Examination of the skin was normal and there was no pigmentation.

Investigations at admission revealed normal sepsis screen. Chest X-ray was suggestive of gross cardiomegaly with a cardiothoracic ratio of 90%. The left lung was not visualized [Figure 1]. ECG was suggestive of regular sinus rhythm and right ventricular hypertrophy. Initial ABG was suggestive of mild respiratory acidosis (ABG - pH 7.26, PCO 2 56, PO 2 63, HCO 3 26). Infant's respiratory distress gradually worsened with progress of time (Downe's score increased to 7). The infant was intubated and put on mechanical ventilation support with patient triggered mode with initial settings of peak inspiratory pressure of 20, peak end expiratory pressure of 5 and with a ventilatory backup rate of 40. Ventilatory support could be reduced over the next 4 days but the infant could not be weaned off completely from the ventilator. A computed tomography scan of the chest revealed a soft tissue density mass lesion (5 cm × 4 cm × 4 cm) in the anterior mediastinum compressing the right ventricle and right atrium encasing the origin of the aorta and the pulmonary artery. The left main bronchus was hypoplastic and significant consolidation of the left hemithorax was seen. There was moderate pericardial effusion [Figure 2]. A magnetic resonance imaging scan of the chest additionally revealed a soft tissue mass lesion isointense to myocardium in free relation of the right ventricle. The right ventricular outflow tract was distended showing significant mass effect. 2D echo was suggestive of severe pulmonary hypertension with mild tricuspid regurgitation.{Figure 1}{Figure 2}

After counseling the parents, the infant was taken up for surgery on Day 16 of life. The heart was approached through a median sternotomy. A large globular mass was seen arising from the right ventricle, encroaching outwards and encasing the origin of great vessels. No definite capsule was present. A frozen section biopsy of the mass was suggestive of rhabdomyoma. The entire tumor was removed piece by piece and a pericardial patch was put to close the wall defect. Post-operatively, the infant developed cardiogenic shock and died within 4 h.

 Discussion



The incidence of primary cardiac tumor in autopsy series ranges from 0.002% to 0.3%. The most common benign tumor is rhabdomyoma. Rhabdomyoma may occur as a single lesion or as multiple lesions usually located within the ventricle. [1] Rhabdomyomas account for 60% of cardiac tumors in neonates and infants. [2] These tumors are closely associated with tuberous sclerosis and occur in more than 50% of patients with this disease. [3],[4],[5],[6],[7],[8],[9],[10] The left ventricle is the most frequently involved site. The tumors most commonly involve the ventricular myocardium, projecting into the ventricular cavity or moving freely as a pedunculated mass. They vary in size, ranging from millimeters to few centimeters. The largest reported cardiac rhabdomyoma is a case in which a 60 mm × 45 mm × 60 mm echo dense mass attached to the left ventricle and cardiac apex with two small tumors in the right ventricle was diagnosed antenatally by fetal echocardiography. [4],[7] The present case is unusual as a large tumor mass arose from the right ventricular wall and extended exteriorly encasing the great vessels, occupying almost the whole middle mediastinum.

The etiology of rhabdomyoma is unknown. Studies have delineated at least two genetic loci on the long arm of chromosome 9 (9q34) and the long arm of chromosome 11 (11q23). [5] Rhabdomyoma resembles a hamartoma derived from embryonal myoblasts. It is thought that the tumor is caused by mutations in the TSC1 and TSC2 genes. Cardiac rhabdomyomas exhibit a fetal pattern of ANP immune reactivity, which suggests delayed maturation of the tumoral cardiomyocytes, reinforcing the notion that cardiac rhabdomyomas are fetal hamartomas. [6]

They grossly appear as yellow-tan solid, circumscribed, unencapsulated tumors. Microscopically, eosinophilic, polygonal cells containing glycogen-rich cytoplasmic granules are seen and myofibrils are seen using an electron microscope. [2] The characteristic of this lesion is the presence of spider cells. The spider cell is a large clear cell with cytoplasmic strands composed of glycogen extending to the plasma membrane. [8]

Cardiac rhabdomyomas may be asymptomatic or may present with hydrops in the fetus. Alternatively, there may be evidence of outflow tract obstruction, arrhythmias or cardiomyopathy (rhabdomyositis). Clinical manifestations of tuberous sclerosis include skin lesions (depigmented marks, adenoma sebaceum, shagreen patches), cerebral abnormalities (periventricular calcifications or nodules, seizures, cerebral atrophy) and retinal phakomata. The dermatologic lesions and hypomelanotic macules are usually present at birth. [7] Our patient had no evidence of tuberous sclerosis.

The differential diagnosis of fetal cardiac tumors includes, in order of descending frequency, rhabdomyoma, teratoma, fibroma, myxoma and hemangioma. In glycogen storage disease, the shape of the myocytes is well preserved. In Purkinje cell tumors, there is a foamy myocardial transformation.

The prognosis depends on the number, size and location of the tumors as well as the presence or absence of associated anomalies. Fenogilo has reported that rhabdomyoma cells lose their ability to divide over time, which may account for the spontaneous regression of these tumors noted clinically. [8] Rhabdomyomas grow slowly in utero but tend to regress spontaneously after birth and may eventually disappear. [2] When the diagnosis of a cardiac tumor is made prior to fetal viability, termination of the pregnancy may be offered. Serial ultrasonic examination should be offered to identify signs of congestive heart failure or rhythm disturbances. Conservative neonatal management is indicated in the asymptomatic patient with surgery reserved for those with hemodynamic compromise. Benign cardiac tumors in childhood have an excellent prognosis when completely excised and appear to have a good short-time prognosis even when excision is incomplete. [9] Indications of surgery include presence of significant symptoms in combination with a removable mass. [10] An additional option that may be considered includes cardiac transplantation.

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