EBV+ diffuse large B-cell lymphoma arising within atrial myxoma in Chinese immunocompetent patient.

The incidence rate of Primary cardiac lymphoma is very low. Primary cardiac lymphoma within myxoma is extremely rare disease. So far, these cases have been reported only eight in the world, which has not reported in Chinese so far. Hence, we reported the unique Chinese case of 52-year-old immunocompetent male with primary Epstein-Barr virus positive diffuse large B-cell lymphoma arising within atrial myxoma, and had no evidence of systemic lymphoma. The patient presented right sided body numbness, arm weakness no incentive and mouth twitch. A transthoracic echocardiogram revealed a large intraatrial mass, attached to the left atrial wall. The mass was removed by open thoracic surgery and subsequently diagnosed as malignant diffuse large B-cell lymphoma with myxoma by histopathology. This was the fourth case of discovered Epstein-Barr virus positive diffuse large B-cell lymphoma in a cardiac myxoma reported so far. The patient has been well by followed up for 5 months without chemotherapy. Now we discuss the importance of histodiagnosis and the proper treatment. Epstein-Barr virus positive diffuse large B-cell lymphoma arising within atrial myxoma is an extraordinary lymphoma for better prognosis, avoiding excessive treatment.

Trypanosoma cruzi infection induces morphological reorganization of the myocardium parenchyma and stroma, and modifies the mechanical properties of atrial and ventricular cardiomyocytes in rats.

BACKGROUND: This study investigates morphofunctional adaptations of the heart stroma and parenchyma in rats that are chronically infected with Trypanosoma cruzi. METHODS: Four-month-old male Wistar rats were randomized into control (n=14) and infected (n=14) groups. Infected animals were inoculated with T. cruzi Y strain. After 9 weeks, the animals were euthanized, and the right atrium (RA) and left ventricle (LV) were removed for biochemical, stereological, and cardiomyocyte mechanical analyses. RESULTS: Infected animals presented cardiomyocyte atrophy and myocardial fibrosis. For these animals, the total volume, length, surface area, and cross-sectional area of cardiomyocytes were significantly reduced, and the total interstitial and collagen volumes were significantly increased in the RA and LV compared to the controls. The total volume and length of blood vessels were significantly increased in the LV, and the total blood vessel surface area was significantly higher in the RA of infected animals. RA and LV cardiomyocytes from infected animals exhibited a significant reduction in cell shortening (43.02% and 24.98%, respectively), prolongation of the time to the peak of contraction (17.09%) and the time to half relaxation (23.68%) compared to non-infected animals. Lipid hydroperoxides, but not mineral concentrations, were significantly increased in the RA and LV from infected animals, showing an inverse correlation with cell shortening. CONCLUSIONS: T. cruzi infection induces global structural remodeling of the RA and LV in rats. This remodeling coexists with cardiomyocyte contractility dysfunction, which is possibly related to the abnormal organization of the myocardial stroma and increased cellular lipid peroxidation.

Incidental Epstein-Barr virus associated atypical lymphoid proliferation arising in a left atrial myxoma: a case of long survival without any postsurgical treatment and review of the literature.

We report a case of left atrial cardiac myxoma harbouring an incidental atypical B-cell lymphoid proliferation. Histology disclosed classic myxoma cells embedded in a mucopolysaccharide-rich matrix and a micronodular atypical lymphoid proliferation under the surface of the mass. Myxoma cells were immunoreactive for calretinin, while lymphoid cells expressed B lineage markers (CD 20+, CD79a), without evidence of clonality. Moreover, they were LMP1 positive; EBNA2 negative; KSHV/HHV8 negative; and, by in situ hybridization, EBER/Epstein-Barr virus (EBV) positive and Kappa and Lambda negative. According to the 2008 WHO schemes, the present case shares close similarities either with diffuse large B-cell lymphomas growing in the context of long-standing chronic inflammation or with primary effusion lymphomas, solid variant, both associated with EBV infection. This is the sixth case of incidental atypical lymphoid proliferation discovered in a cardiac myxoma reported so far. The optimal treatment of such lesions remains undefined, but their clinical course is indolent. After an accurate staging workup, without any postsurgical treatment, the patient we observed has been well with no recurrence of the disease at 6 years of follow-up.

Detection of herplex simplex virus-1 and -2 in cardiac myxomas.

The etiology of sporadic cardiac myxomas remains elusive. The tendency for these lesions to recur following resection, their immunopathological characteristics, along with their histological and molecular profile, may implicate the presence of an infective agent in this type of tumor. In this study, we investigated the presence of herpes simplex virus (HSV) DNA in a cohort of cardiac myxomas in a tertiary referral centre. Twenty-nine formalin-fixed paraffin-embedded (FFPE) sporadic cardiac myxomas were obtained, 17 of which were shown to be informative. These were compared to 19 macroscopically and microscopically normal heart tissue specimens. The detection of HSV-1 and -2 genomic sequences was achieved with the use of a combined nested PCR-Restriction Fragment Length Polymorphism methodology. The presence of HSV-1 and/or -2 DNA was demonstrated in 6 of 17 (35%) informative sporadic cardiac myxomas, whereas no HSV DNA was detected in normal heart tissues (P < 0.01). The existence of HSV-1/2 DNA in sporadic cardiac myxomas, along with its absence from normal heart tissues, reinforces the possibility that HSV infection might be involved in the development of these lesions. Our findings raise the point of anti-HSV medication postsurgically with a potential benefit in reducing the rate of recurrences.

Regulation of chamber-specific gene expression in the developing heart by Irx4.

The vertebrate heart consists of two types of chambers, the atria and the ventricles, which differ in their contractile and electrophysiological properties. Little is known of the molecular mechanisms by which these chambers are specified during embryogenesis. Here a chicken iroquois-related homeobox gene, Irx4, was identified that has a ventricle-restricted expression pattern at all stages of heart development. Irx4 protein was shown to regulate the chamber-specific expression of myosin isoforms by activating the expression of the ventricle myosin heavy chain-1 (VMHC1) and suppressing the expression of the atrial myosin heavy chain-1 (AMHC1) in the ventricles. Thus, Irx4 may play a critical role in establishing chamber-specific gene expression in the developing heart.