Invasive Giant B-Cell Lymphoma Mimicking Fulminant Pulmonary Embolism

Background  Cardiac non-Hodgkin's lymphoma is rare and has a poor prognosis. Here we report a rare case mimicking pulmonary embolism.

Case Description  A 38-year-old woman suffered from severe dyspnea after cesarean section. With the clinical picture of fulminant central pulmonary embolism, lysis therapy was initiated. Further deterioration necessitated extracorporeal membrane oxygenation (ECMO) support and cardiosurgical intervention. Intraoperatively, a massive intravascular tumor obstructed the pulmonary bifurcation and was found to be B-cell lymphoma. Aggressive excision and pulmonary tree reconstruction improved the critical condition and initiated convalescence.

Conclusion  High suspicion in central pulmonary embolism and early cardiosurgical therapy after ineffective lysis are essential.

Myocardial Accumulations of Reg3A, Reg3γ and Oncostatin M Are Associated with the Formation of Granulomata in Patients with Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a poorly understood disease and is characterized by the focal accumulation of immune cells, thus leading to the formation of granulomata (GL). To identify the developmental principles of fatal GL, fluorescence microscopy and Western blot analysis of CS and control patients is presented here. CS is visualized macroscopically by positron emission tomography (PET)/ computed tomography (CT). A battery of antibodies is used to determine structural, cell cycle and inflammatory markers. GL consist of CD68⁺, CD163⁺ and CD206⁺ macrophages surrounded by T-cells within fibrotic areas. Cell cycle markers such as phospho-histone H3, phospho-Aurora and Ki67 were moderately present; however, the phosphorylated ERM (ezrin, radixin and moesin) and Erk1/2 proteins, strong expression of the myosin motor protein and the macrophage transcription factor PU.1 indicate highly active GL. Mild apoptosis is consistent with PI3 kinase and Akt activation. Massive amounts of the IL-1R antagonist reflect a mild activation of stress and inflammatory pathways in GL. High levels of oncostatin M and the Reg3A and Reg3γ chemokines are in accordance with macrophage accumulation in areas of remodeling cardiomyocytes. We conclude that the formation of GL occurs mainly through chemoattraction and less by proliferation of macrophages. Furthermore, activation of the oncostatin/Reg3 axis might help at first to wall-off substances but might initiate the chronic development of heart failure.

Reactive mesothelial hyperplasia mimicking mesothelioma in an African green monkey (Chlorocebus aethiops)

A spontaneous reactive mesothelial hyperplasia occurred in a female, 15.7-year-old African green monkey (grivet; Chlorocebus aethiops). At necropsy, massive effusions were found in the abdomen, the thorax, and the pericardium. Additionally, multiple small, beige-gray nodules were detected on the serosal surfaces of the abdominal organs. Histopathologically, the mesothelial cells resembled the epithelioid subtype of a mesothelioma, but no infiltrative or invasive growth could be demonstrated. The mesothelial cells on the thoracis, liver, and intestinal serosa were accompanied by chronic serositis. Mesothelial cells expressed cytokeratin, vimentin, calretinin, desmin, Wilms Tumor 1 (WT-1) protein, and epithelial membrane antigen (EMA). Cells were negative for carcinoembryonic antigen (CEA), cluster of differentiation 15 (CD15), and podoplanin. Ultrastructurally, cells revealed a moderate amount of microvilli of medium length, perinuclear tonofilament bundles, and long desmosomes. In fluorescence in situ hybridization (FISH) for the detection of characteristic gene loss (p16; CDKN2A), NF2, and MTAP, no deletions were detected. No asbestos fibers and no presence of Simian virus 40 antigen (SV40) could be demonstrated.

Rapidly progressive hypertrophic cardiomyopathy in an infant with Noonan syndrome with multiple lentigines: palliative treatment with a rapamycin analog

Noonan syndrome with multiple lentigines (NSML) frequently manifests with hypertrophic cardiomyopathy (HCM). Recently, it was demonstrated that mTOR inhibition reverses HCM in NSML mice. We report for the first time on the effects of treatment with a rapamycin analog in an infant with LS and malignant HCM. In the boy, progressive HCM was diagnosed during the first week of life and a diagnosis of NSML was established at age 20 weeks by showing a heterozygous Q510E mutation in PTPN11. Immunoblotting with antibodies against pERK, pAkt, and pS6RP in fibroblasts demonstrated enhanced Akt/mTOR pathway activity. Because of the patient's critical condition, everolimus therapy was started at age 24 weeks and continued until heart transplantation at age 36 weeks. Prior to surgery, heart failure improved from NYHA stage IV to II and brain natriuretic peptide values decreased from 9,600 to <1,000 pg/ml, but no reversal of cardiac hypertrophy was observed. Examination of the explanted heart revealed severe hypertrophy and myofiber disarray with extensive perivascular fibrosis. These findings provide evidence that Akt/mTOR activity is enhanced in NSML with HCM and suggest that rapamycin treatment could principally be feasible for infantile NSML. The preliminary experiences made in this single patient indicate that therapy should start early to prevent irreversible cardiac remodelling.

In vitro evaluation of the sinus sagittalis superior thrombosis model in the rat using 3D micro- and nanocomputed tomography

INTRODUCTION

Thrombosis of the cerebral veins and sinus are common causes of stroke. Animal models help us to understand the underlying pathophysiology of this condition. Therefore, the purpose of our study was to evaluate a well-established model for sinus sagittalis (SSS) thrombosis using micro- and nanocomputed tomography (CT) imaging.

METHODS

SSS thrombosis was performed in four rats. After contrast perfusion, brains were isolated and scanned using micro-CT at (8 microm)(3) voxel size to generate 3D images of the cerebral vasculature. For more detailed information on vascular perfusion territories, nano-CT imaging was performed to investigate the boundary layer of contrast-enhanced vessels and the occluded veins. The venous and arterial vascular volume fraction and gray scale measurements were obtained in the SSS thrombosis group and compared to controls. The significance of differences in vascular volume fraction and gray scale measurements was tested with analysis of variance. Results were complemented with histology.

RESULTS

Micro-CT proved to accurately visualize and differentiate vascular occlusion territories performed in the SSS thrombosis model. Moreover, 3D micro-CT provided quantitative information on arterial and venous vascular volume fraction. Micro-CT imaging enables a total 3D visualization of complications (ventricle rupture) in the SSS thrombosis model. We established gray scale measurements by which focal cerebral ischemia could be radiographically categorized (p < 0.001).

CONCLUSIONS

Using nano-CT, the interface of contrast-perfused and occluded veins can be visualized. Micro-CT is feasible for analysis and differentiation of perfusion territories in an animal model of focal cerebral ischemia.

Aortic valve stenosis due to alkaptonuria

Cardiovascular disease is a less-well appreciated aspect of alkaptonuria. A 69-year-old man presented with shortness of breath and exertional chest pain. He had a previous diagnosis of alkaptonuria (endogenous ochronosis), confirmed on the basis of urine coloration, skin pigmentation and ochronotic arthropathy in the knees. Echocardiography and coronary angiography revealed severe aortic valve stenosis and concomitant coronary artery disease. The patient underwent biological aortic valve replacement (AVR) and coronary artery bypass grafting (CABG). Operative findings included ochronosis of a severely calcified aortic valve and the aortic intima, and bioprosthetic AVR and CABG were successfully performed.

Atherosclerotic lesions at micro CT: feasibility for analysis of coronary artery wall in autopsy specimens

PURPOSE

To evaluate the feasibility of micro computed tomography (CT) for analysis of the coronary artery wall.

MATERIALS AND METHODS

With micro CT, two-dimensional transverse images were generated from 10 human autopsy specimens of coronary arteries (2.5-3.5 cm long), with section thickness of 6 microm. Vessel wall perimeter, plaque area, calcified lesion area, media area, and lumen area were determined by three experienced radiologists. Results were compared with those obtained from a detailed conventional histomorphometric analysis of corresponding cross sections. Hotelling T(2) test (a multivariate generalization of the univariate Student t test) and Pearson correlation coefficient were used to assess the correlation between micro CT findings and conventional histologic measurements. The significance of differences in gray-scale measurements was tested with analysis of variance.

RESULTS

Micro CT provided quantitative information about plaque morphology equivalent to that provided with histomorphometric analysis. Hotelling T(2) test revealed significantly smaller values for vessel wall perimeter and lumen area with histologic sections (P <.001). Gray-scale measurements were established with which lesions could be categorized after histologic classification.

CONCLUSION

Micro CT is feasible for analysis of the coronary artery wall.