M. Occhiogrosso

Ultrastructural and Morphometric Investigation of Human Brain Capillaries in Normal and Peritumoral Tissues

Capillaries of peritumoral and normal brain tissues were ultrastructurally and morphometrically investigated to evaluate the changes in peritumoral capillaries connected with the tumor-associated vasogenic edema. The endothelial cells of peritumoral capillaries showed varying thickness, electron-lucent cytoplasm, and structurally normal tight junctions. The basal lamina was thickened, rarefied, and vacuolated. The pericytes were provided with pinocytotic vesicles and phagocytic bodies. The astrocytic glia appeared empty or swollen, with few glycogen granules and a disarranged cytoskeleton; well-preserved glia was occasionally observed. The brain tissue was slightly edematous. No statistically significant differences were observed between normal and peritumoral capillaries as regards diameter, wall thickness, endothelial thickness, and endothelial vesicle density. Instead, the peritumoral capillaries displayed three times as many endothelial surface-connected vesicles, a markedly thicker basal lamina, and significantly reduced extension of pericytic and glial investments. The kind and severity of the vascular modifications, compared with the slight edematous appearance of the nervous tissue, strengthen the hypothesis that peritumoral capillaries could be involved in the edema resolution process.

Respiratory distress caused by migration of ventriculoperitoneal shunt catheter into the chest cavity: report of a case and review of the literature

A case is reported in which the peritoneal catheter of a ventriculoperitoneal shunt migrated into the chest cavity causing an hydrothorax. The three similar cases drawn from the literature are reported.

Radiation-induced intracranial meningiomas: review of six operated cases

It is well known that radiation can induce meningiomas. These tumors usually arise in patients with a history of low-dose radiation to the scalp for treatment of tinea capitis or high-dose radiation for a previous brain tumor. Radiation-associated meningiomas (RAMs) morphologically resemble their spontaneously arising counterparts. However, RAMs frequently present a more malignant phenotype and, as such, are diagnosed as “atypical” or “aggressive” meningiomas and occur predominantly in younger patients. This paper describes six cases of radiation-associated intracranial meningiomas in patients previously treated with low-dose radiation to the scalp for tinea capitis.

Malignant chemodectoma of the carotid body causing spinal cord compression

We present a case of a 19-year-old woman with a malignant chemodectoma of the carotid body invading the cervical spine. The interest in the case is due to the rarity both of the lesion and of the spine invasion causing a medullary compression.

Evaluation of the Ar+ laser thermal effect in rabbit brain tissue by means of optical absorption coefficients. Photoacoustic measurements

SummaryIn predicting Ar+ laser-neural tissue interaction a determination of the optical absorption properties of brain parenchyma appears indispensable. In this study a determination of absorption spectra of different areas of rabbit brain at the wavelength of an Ar+ laser beam is made. The areas considered in the study are frontal and occipital gray and white substance, thalamus, basal ganglia, cerebellar cortex and choroid plexus. Specimens of these areas measuring 2×3×3 mm were obtained from coronal sections 1 cm thick of 20 rabbit brains. The analysis of optical properties was made by means of a photoacoustic spectrometer which appears the only suitable technique for testing the optical absorption properties of biological materials. The absorption coefficient results were similar in magnitude and constant in all the areas examined, measuring approximately 50 cm−1. The prediction of lack of any selective effect for the different areas is confirmed by the sizes of lesions made in cerebral specimens of the same areas of the contralateral hemisphere by means of Ar+ laser: the lesions increase in size in proportion to the increase in output power and exposure time, independently of the areas considered. Also the histological examination of the areas shows the same morphology to be independent of the variations of both output power and exposure time. The only differences were the presence for short exposure time and low output power of a carbonized layer inner to the layer of coagulative necrosis.

Prenatal diagnosis of craniopagus

The long‐term prognosis of craniopagus, a congenital abnormality of monozygotic twinning, is strictly correlated to the type of shared cerebral structures. Hence, the purpose of prenatal diagnosis is not only to detect this malformation, but also to identify the fused cerebral structures. The authors report a prenatal diagnosis of a craniopagus during the second trimester of pregnancy. Comparison of ultrasound data with the pathological findings underlines that ultrasound is of great value in detecting malformations, but it is not alone sufficient to identify the types of conjoined cerebral structures.