Cardiac Rhabdomyoma
Cardiac rhabdomyoma is a benign tumor originating from striated muscle cells. Along with extra-cardiac rhabdomyomas, it belongs to the rhabdomyoma family.
- PDF / 141,785 Bytes
- 3 Pages / 439.37 x 666.142 pts Page_size
- 83 Downloads / 325 Views
46
Definition Cardiac rhabdomyoma is a benign tumor originating from striated muscle cells. Along with extra-cardiac rhabdomyomas (which include adult, fetal, and genital rhabdomyoma; for details → see dedicated sections), it belongs to the rhabdomyoma family (→ see also the section entitled “Rhabdomyoma”).
Epidemiology and Presentation It represents 50–90% of primary heart tumors in children. It is usually discovered in patients during the first year of life. It may obstruct valvular orifice or cardiac chamber causing hemodynamic effects and may present with sudden cardiac death. It is believed to be caused by inactivating mutations in TSC1 and TSC2 tumor suppressor genes. It can be sporadic or syndromic (→ see below paragraph).
Etiology and Predisposition About 50% of patients have tuberous sclerosis complex (TSC), a genetic syndrome inherited in an autosomal dominant manner and caused by inactivating mutations in TSC1 (9q34) and TSC2 (16p13.3) tumor suppressor genes (which encode proteins inhibiting the mTOR pathway). TSC is characterized by multisystem hamartomas/tumors, most frequently observed in the skin, brain, kidney, lung, and heart. Skin involvement includes the following: hypomelanotic macules (ash leaf, within the first years of life), angiofibromas (appear at the age of 3–4 years as erythematous and papulo-nodular lesions; → see dedicated section), ungual fibromas, cephalic and lumbar fibrous plaques (shagreen patch), and ”confetti” skin lesions (childhood to adolescence). The brain is involved in almost all cases of TSC in particular with © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. Mocellin, Soft Tissue Tumors, https://doi.org/10.1007/978-3-030-58710-9_46
159
160
46 Cardiac Rhabdomyoma
cortico/subcortical tubers and subependymal giant cell astrocytoma (SEGA, which can cause hydrocephalus). Early-onset epilepsy is present in 85% of patients. Neuropsychiatric features have also been reported. Renal angiomyolipoma (→ see dedicated section) develops during childhood and presents with pain, hematuria, retroperitoneal hemorrhage, abdominal masses, hypertension, and renal failure. Lymphangioleiomyomatosis (→ see dedicated section), multifocal micronodular pneumocyte hyperplasia (MMPH) and pulmonary cysts develop during adulthood and manifest with dyspnea, pneumothorax, or chylothorax. Cardiac rhabdomyoma can appear during the fetal period and may become symptomatic (outflow tract obstruction or by interfering with valvular function) during infancy and childhood.
Pathology Macroscopically, the lesion presents as a small, firm, gray to white, well- circumscribed myocardial mass (often multiple) that protrudes into ventricles (average size: 3–4 cm). Microscopically, the tumor is composed of clear cells and large, rounded, polygonal cells (“spider cells”) with glycogen vacuoles separated by strands of cytoplasm extending between cell membrane and nucleus. No mitotic activity is usually detected. Differential diagnosis may be
Data Loading...
