Postmortem microcomputed tomography (micro-CT) of small fetuses and hearts.

OBJECTIVE: To assess the feasibility and utility of contrast-enhanced microcomputed tomography (micro-CT) for identifying structural anomalies in ex-vivo first- and second-trimester human fetuses and isolated fetal hearts. METHODS: Radiopaque iodine staining and micro-CT scanning protocols were first developed in rodent studies and then used to examine routinely fixed whole human fetuses (n = 7, weight 0.1-90 g, gestational age, 7-17 weeks) and isolated fetal hearts (n = 14, weight 0.1-5.2 g, gestational age, 11-22 weeks). Samples were scanned using an isotropic resolution of 18 (and, if necessary, 9 or 35) µm and findings were interpreted jointly by four fetal pathologists, a fetal cardiologist and a radiologist. Samples with gestational ages ≥ 13 weeks also underwent conventional autopsy or dissection. RESULTS: Micro-CT identified all anatomical structures and abnormalities documented by the macroscopic examination. In all seven cases involving fetuses ≤ 13 weeks (four fetuses, three isolated hearts), micro-CT excluded the presence of structural anomalies. In the remaining 14 cases, it provided all the information obtained with invasive autopsy or dissection and in seven of the 14 (two fetuses, five isolated hearts) it furnished additional diagnostic details. CONCLUSIONS: This pilot study confirms the feasibility of postmortem contrast-enhanced micro-CT assessment of structural anomalies in whole small fetuses and fetal hearts. Further study is needed to confirm our findings, particularly in whole fetuses, and to define the extent to which this virtual examination might be used instead of conventional invasive autopsy.

Alteration of elastin, collagen and their cross-links in abdominal aortic aneurysms.

OBJECTIVES: although the mechanism of arterial dilation and aneurysm development has not been clarified, the degradation of elastin and collagen plays undoubtedly a critical role. We evaluated the elastin and collagen content through the detection of their cross-links in aneurysmal and non-aneurysmal abdominal aortic walls. MATERIALS AND METHODS: in 26 human abdominal aortic aneurysm specimens obtained during surgery and in 24 autopsy control samples of non-aneurysmal abdominal aorta the tissue content of elastin and collagen cross-links were measured by HPLC. Collagen was also detected by evaluating two characteristic amino acids, 4-hydroxyproline (4-hypro) with a colorimetric method and 5-hydroxylysine (5-hylys) by gas chromatography. RESULTS: significantly fewer elastin cross-links were found in aneurysm samples compared to controls (desmosines and isodesmosines: 90% reduction; p<0.01). The opposite was true for pyridinoline collagen cross-links (350% increase) and deoxypyridinolines (100% increase, p=0.01). Tissue content of 5-hylys, 4-hypro and total amino acids were reduced significantly by 50% in aneurysmal samples. CONCLUSIONS: beside confirming decreased elastin content in aneurysmal walls, these results show a concurrent increase of collagen cross-links. Since total collagen markers were decreased (decreased 4-hypro and 5-hylys) it is reasonable to suggest that in aneurysmal aortic walls old collagen accumulates cross-links while new collagen biosynthesis is somehow defective.

[Anatomopathological and immunohistochemical findings in 6 cardiac myxomas]. / Osservazioni anatomopatologiche e immunoistochimiche di 6 mixomi cardiaci.

Heart myxoma is the most common cardiac neoplasm in adult, even if its biologic profile remains uncertain. The clinicopathologic features of 6 cardiac myxomas in patients ranging in age from 42 to 58 years are described: 5 cases were located in atria, 1 occurred in the right ventricular wall, attached by a thin pedicle to the wall next to the pulmonary artery. Grossly myxomas are generally pedunculated and average 2 to 8 cm in diameter. They appear gelatinous and polypoid, sometimes with areas of hemorrhage. Microscopic examination of specimens of myxomas removed at operation reveals the myxomatous nature of the stroma composed of abundant mucopolysaccharidic matrix, containing stellate or polyhedral cells, singly or in small clusters, and occasional blood vessels. In other cases, the matrix stains more deeply and reticulin fibers and occasional strands of collagen are evident. Immunohistochemical study reveals tumoral positivity for smooth muscle actin cells and for vimentin. In addition, endothelial cells in intramyxomatous vascular channels are positive for factor VIII and CD-34 endothelial markers. Myxomas were diagnosed in patients in whom the symptoms and signs of cardiac tumor may have been attributed to other causes. The clinical pictures produced by cardiac myxomas include non specific manifestations and mechanical interference with cardiac function. The symptoms may simulate a wide variety of other cardiac conditions (mitral valve disease, embolic phemomena, tricuspid valve disease, sudden unexpected death). A wide local excision is needed to assure that the myxoma does not recur.

[Sudden cardiac death in acromegaly. Anatomopathological observation of a case]. / Morte improvvisa cardiaca nell'acromegalia. Osservazione anatomopatologica di un caso.

Involvement of the cardiovascular system in patients affected by acromegaly is an important factor in morbidity and mortality. The diagnosis in these subjects is acromegalic cardiomyopathy with cardiac decompensation, arrhythmias and sudden death. The pathologic substrate has rarely been described. The present study reports the findings in a case of sudden death in a 54-year-old man, affected by acromegaly. Subsequent diagnostic investigation revealed the characteristic aspects of acromegalic cardiomyopathy in the common myocardium and the presence of hyperacute myocardial infarct of the antero-septal wall of the left ventricle. Examination of conduction tissue revealed slight fibrolipomatosis and dispersion of the atrio-ventricular node (AVN), which extended to the His bundle and bifurcation. The right branch was prematurely intramural with sclerosis and lipomatosis. This location in atrio-ventricular conduction system has seldom been reported in the literature and if so, with different lesions from those found in the case we investigated. The results of microscopic examination convalidate the hypothesis of electrical instability in the heart, as confirmed by the subject's history of ventricular extrasystoles, left branch block and attacks of angina after effort. Death was correlated to hyperacute myocardial infarction of the anteroseptal wall of the left ventricle, in a subject with history of angina, affected by acromegalic cardiomegaly and electric instability. In this case, sudden death could also be considered arrhythmogenic in relation to the additional workload by persistent hormonal stimulation.