Histopathologic and clinical characterization of cardiac myxoma: Review of53 cases from a single institution

Background Cardiac myxomas have varying clinical presentation, uncertain hi stogenesis, and debatable immunohistochemical profile. A few malignant case s have been previously reported. Methods Fifty-three consecutive cardiac myxomas were histologically investi gated and results compared with clinical data. The main goal of the study w as to investigate the immunohistochemical differentiation and the clinicopa thologic correlations. Results Stromal cells were characterized by the expression of the von Wille brand factor endothelial marker (12 of 53 cases) and diffuse cytoplasmic ne uropeptides such as protein gene product 9.5 (50 of 53 cases), S100 protein (47 of 53) and neuron-specific enolase (30 of 53), all of which were expre ssed in 30 (57%) of 53 tumors. Stromal cells did not show endocrine granule s, epithelial, or smooth muscle immunoreactivity. Non-cardiac-related sympt oms were observed in 7 of 53 patients and promptly disappeared after tumor excision; median values and percentages of total immunoreactivity scores fo r neuropeptides were higher in these 7 cases, but data analysis showed no s tatistical significance. Glands were detected in 2 myxomas, and they showed epithelial (cytokeratins and carcinoembryonic antigen), protein S100, and neuron-specific enolase immunoreactivity; this pattern has been previously detected in human gut. All tumors showed benign behavior, and no mitosis wa s detected. Conclusions The results of this study support the hypothesis that stromal c ells originate from multipotent mesenchyme capable of neural and endothelia l differentiation; rare myxoma glands would represent entrapped foregut res ts. A correlation could exist between neuroendocrine differentiation and no n-cardiac-related symptoms.