Figure 1: (a) Histological evaluation of representative HSV-positive and HSV-negative cardiac myxoma cases. Hematoxylin-eosin (H&E) staining of myxoma tissue sections revealed sparsely cellular lesions with a characteristic gel-like stroma of acid mucopolysaccharides, containing individual small cells with sparse cytoplasms forming stellate protrusions into the stroma. (i) HSV-negative left atrial myxoma sample (case 1). (ii) HSV-positive right ventricle myxoma sample (case 7) (×200 magnification, H&E staining). (b) Detection of HSV DNA in representative atrial myxoma specimens. M: 100 bp molecular marker (New England Biolabs), 1–13: atrial myxoma samples, cases 1, 2, 4–6, 8–13: HSV-negative samples, cases 3, 7: HSV-positive samples, 14: positive control (blood sample), and 15: negative control (normal heart tissue).