Presence of satellite cells in a cardiac rhabdomyoma

Abstract

Cardiac rhabdomyoma is the most common tumour of the heart in infancy and childhood. The clinical presentation, diagnosis and histopathological characteristics have been extensively studied; however, reports on the ultrastructure and histogenesis of this lesion are scanty and inconclusive. The case to be discussed is that of a 10-year-old male who presented with a cardiac rhabdomyoma occupying almost the entire ventricular apex. Ultrastructurally, the rhabdomyoma cells have a central, deeply-indented nucleus surrounded by an admixture of mitochondria and sarcomeres. The remainder of the cytoplasm is occupied by pools of glycogen granules, randomly-orientated myofibrils and small mitochondria. Intercellular junctions are numerous and consist of alternating zonula occludens and macula adherens. Typical satellite cells, sharing a common basement lamina are seen apposed to the rhabdomyoma cells. It is tempting to postulate that the proliferation of the rhabdomyoma cells is accomplished by differentiation of satellite cells, a process known to occur in skeletal muscle. Ultrastructurally, the rhabdomyoma cells are indistinguishable from Purkinje cells. The presence of Purkinje-like cells in ectopic locations within the heart and their association with satellite cells is likely a form of embryological atavism.

The pathogenesis of so-called cardiac rhabdomyoma in swine: a histological, immunohistochemical and ultrastructural study

“…We used the same antiserum in this study, and found positivity of the CR cells like that of Purkinje cells. However, ANP is produced and secreted by ventricular myocytes in several human heart diseases [36], although the precise mechanism of this is unknown. We confirmed the fact in swine myocarditis (Table 3).…”

“…Only specimens stained with PAS were prepared from methacarn-fixed materials. For immunohistochemical studies, we adopted the avidin-biotin-peroxidase complex (ABC) method using paraffin-embedded sections and the primary antibodies reactive with striated muscle cells and their neoplasms (Table 2) [14,24,29,36,39,40]. To investigate proliferating activities of the CR cells, staining for proliferating cell nuclear antigen (PCNA) was also done.…”

Two Novel Approaches Providing Cardiac Protection Against Oxidative Stress

“…EM analysis also showed significant swelling of the mitochondria in MsrA-/-mouse hearts and protein oxidation levels in MsrA-/-mouse hearts were higher than those of wild type controls (Nan et al, 2010). Similar morphological changes in mitochondria have previously been reported in diseased hearts either from dilated cardiomyopathy or from myocardial ischemia and such ultrastructural changes have been associated with aging and senescence (Trillo et al, 1978;Schaper et al, 1991;Scholz et al, 1994;Terman et al, 2004) . This study indicates that there is a serious defect in mitochondrial function in t h e h e a r t s o f M s r A -/ -m i c e r e s u l t i n g i n compromised contractility and cellular dysfunction, especially under stress (Nan et al, 2010).…”

Novel Strategies in Ischemic Heart Disease

“…EM analysis also showed significant swelling of the mitochondria in MsrA-/-mouse hearts and protein oxidation levels in MsrA-/-mouse hearts were higher than those of wild type controls (Nan et al, 2010). Similar morphological changes in mitochondria have previously been reported in diseased hearts either from dilated cardiomyopathy or from myocardial ischemia and such ultrastructural changes have been associated with aging and senescence (Trillo et al, 1978;Schaper et al, 1991;Scholz et al, 1994;Terman et al, 2004) . This study indicates that there is a serious defect in mitochondrial function in the hearts of MsrA-/-mice resulting in compromised contractility and cellular dysfunction, especially under stress (Nan et al, 2010).…”