Immunohistochemical expression of endothelial markers in left atrial myxomas: a study of six cases

Abstract

Vascular endothelial cells are antigenically heterogeneous and therefore it has been recommended that a range of immunohistochemical markers is employed to show the presence of cells of endothelial origin in surgical pathology. In this study we applied three monoclonal antibodies--to factor VIII-related antigen, JC70 (CD31), QBend 10 (CD34)--and Ulex europaeus agglutinin type 1 lectin (UEA-1), to six consecutive cases of left atrial myxoma. We found that JC70 and QBend 10 consistently stained myxoma cells in all their different growth patterns contrasting with factor VIII-related antigen expression and UEA-1 binding which were restricted to areas which showed morphological evidence of vascular differentiation. These findings suggest that the constituent cells of atrial myxomas show more widespread endothelial differentiation than has previously been recognized and that differences in immunohistochemical staining may reflect the maturation status of these cells.

Molecular Basis of Cardiac Myxomas

“… Abbreviations : ACTA2, actin, alpha2, smooth muscle [33,91]; ACTC1, actin, alpha, cardiac muscle1 [30]; C3, Compliment component 3 [27]; CCR2, chemokine receptor 2 [92]; CD34 and CD44(Indian blood group) [93,94]; CEACAM, carcinoembryonic antigen-related cell adhesion molecule 5 [32,95]; CXCL1, chemokine ligand1 [25]; EDN1 and EDN3, endothelin1 and 3 [26]; ENG, endoglin [27]; FVIII/vWF, factor VIII related antigen/ von Willebrand factor [30,33]; FGF2, fibroblast growth factor2 [96]; FGFR1, fibroblast growth factor receptor1 [96]; FLT1/VEGFR1, fms-related tyrosine kinase 1 (vascular endothelial growth factor receptor) [30,97]; FMOD, fibromodulin [27]; FN1, fibronectin [27]; GATA4, GATA binding protein 4 [28]; HAND1, heart and neural crest derivatives expressed 1 [28]; IL6 and IL8, interleukin 6 & 8 [98]; ITGB4, integrin beta4 [27]; KRT19, keratin19 [63]; MCP1, Monocyte chemoattractant protein1 [92]; MIA, melanocyte inhibitory activity [27]; MIB1, mindbomb homolog1 [99]; MMP, matrix metallopeptidase [100]; MUC5AC, mucin5AC [101]; MYH10, myosin, heavy chain10 [102]; NFATC1, nuclear factor of activated T cells [30]; NKX2-5, transcription factor related locus 5 [28]; NOTCH1, Notch homolog1 [30]; PCNA, proliferating cell nuclear antigen [96,103]; PDGF-AA, alpha platelet derived growth factor alpha [97]; PECAM1, platelet endothelial cell adhesion molecule [33,103]; PKP2, plakophilin 2 [104]; PLA2G2A: phospholipaseA2 [26]; RB1, retinoblastoma1 [105]; SMAD6, family member 6 [30]; SOX9, (sex determining region)-box9 [27,30]; SPP1, secreted phosphoprotein1 [27]; TNC, tenascin C [94]; TIMP2...…”

Large Right Atrial Myxoma Containing Gastric Heterotopia Presenting with Dyspnea and Bilateral Leg Edema due to Pulmonary Emboli and Cardiovascular Obstruction: The First Known Report of Gastric Heterotopia in the Cardiovascular System

“…Ultrastructural evidence suggests that atrial myxomas arise from multipotential mesenchymal cells, ranging in differentiation from relatively undifferentiated to cardiomyocyte-like progenitor cells [42]. A specific relation between atrial myxomas and cardiomyoctes is supported by immunohistochemistry [43], and by molecular genetic analysis [44].…”

Villous Hypertrophy versus Choroid Plexus Papilloma: A Case Report Demonstrating a Diagnostic Role for the Proliferation Index

“…The histological features of CPP may be very similar to those of normal choroid plexus [8, 9, 10, 16], making it very difficult to distinguish CPP from VH. Although several subtle features can characterize papillomas, including elongated, columnar epithelial cells, nuclear crowding, stratification or pseudostratification, and a flattened instead of the normal ‘hobnailed’ free surface [10, 11, 12, 16, 19], the biological significance of these various histopathological features remains controversial [20]. …”

“…Several studies have noted a disappointing lack of correlation between histological characteristics and clinical outcome [10, 19, 21, 22]. Although rare, there are several reported cases of CPP recurrence in the literature [20, 23]. Of note, LeBlanc et al [24]report a case of a histologically benign CPP with diffuse and extensive leptomeningeal metastasis.…”

“…Additionally, among CPP, the highest proliferative potential was seen in the primary lesion of a recurring papilloma. Vajtai et al [20]provided further evidence that the proliferative index may serve as a useful marker for assessing the degree of neoplastic activity and potential for recurrence. In their study, mean labeling indices for Ki-67, an antigen associated with cell proliferation, with the MIB-1 antibody were 0.2–6% (mean 3.7%) for CPP and 7.3–20.5% (mean 14%) for CPC.…”