Multiple cardiac rhabdomyomas in tuberous sclerosis complex: case report and review of the literature

Abstract

Cardiac rhabdomyoma is a benign tumor which constitutes the most common cardiovascular feature of the tuberous sclerosis complex, a multisystem genetically determined neurocutaneous disorder. Cardiac rhabdomyomas can be detected in the prenatal ultrasound, are usually asymptomatic and spontaneously regress within the first three years of life. Less often, the tumors' size, number, and location can produce a mass effect that may lead to blood flow abnormalities or organ dysfunction (heart failure and arrhythmia). In this setting, severe morbidity, and eventually, a lethal outcome despite clinical and surgical treatment may ensue. We describe a fatal case of multiple cardiac rhabdomyomas in a newborn girl. One of the rhabdomyomas was large and unfavorably located, causing significant obstruction of the left ventricular outflow tract. The autopsy identified, in addition to cardiac rhabdomyomas, brain glioneuronal hamartomas (cortical tubers), subependymal nodules and subependymal giant cell tumors, characteristic of the tuberous sclerosis complex. The newborn's family was investigated for the presence of typical clinical symptoms of the complex and image findings showed significant phenotypical variations and a broad symptom spectrum among the family members. This interesting case underscores the variability of tuberous sclerosis complex and the importance of performing a comprehensive postmortem examination in the identification of the cause of death, especially in the setting of familial disease.

Keywords: Heart Neoplasms; Infant, Newborn; Neurocutaneous Syndromes; Rhabdomyoma; Tuberous Sclerosis.

Figure 1. Gross view of the heart. A - Anterior face of the heart showing several whitish nodules (arrowheads); B - Right ventricular outflow tract with some of the nodules represented on the cut surface (arrowheads); C - Left ventricular outflow tract evidencing subaortic obstruction by the largest rhabdomyoma of the interventricular septum (arrowhead).

Figure 2. Photomicrograph of the heart. A - Panoramic view of cardiac rhabdomyomas represented by large and clear cell nodules (HE 1x); B - Rhabdomyoma composed of a proliferation of large and vacuolated cells with a centrally placed nucleus and cytoplasmic strands extending to the periphery of the cell – “spider cell” (HE 10X).

Figure 3. Macroscopic aspect of the brain showing cortical tubers (white arrowhead) and subependymal nodular lesions arising in the walls of the lateral ventricles (black arrowheads).

Figure 4. Photomicrographs of the brain. A and B - Subependymal nodules (A, HE 1X; B, HE 3X), comprised by a proliferation of neuronal cells and large and atypical glial cells; C - Large subependymal lesion (HE 1.44X), comprised by the proliferation of large cells of eosinophilic cytoplasm with moderate pleomorphism (D, HE 20X).