Sebastiano Lucerna

Peritumoral edema in meningiomas: microsurgical observations of different brain tumor interfaces related to computed tomography.

Although generally benign tumors, meningiomas may be associated with extensive peritumoral brain edema as seen on computed tomographic scans. Fifty-two patients with intracranial meningiomas were studied, and the hypodense areas on computed tomographic scans were related to the intraoperative microsurgical findings and to the sizes of the tumors. We have identified three kinds of tumor-brain interfaces characterized by different difficulties in microsurgical dissection: smooth type, transitional type, and invasive type. These different microsurgical interfaces seem to correlate very precisely with computed tomographic images of halo-like and finger-like hypodense areas, allowing prediction of the microsurgical effort to be made in the surgery of meningiomas. The size of the tumor seems to be important in our subjects in determining the amount of edema produced. Indeed, a positive correlation (P < 0.001) was found between the sizes of the tumors and the extent of peritumoral hypodensity. A positive correlation (P < 0.002) also has been found between grade of edema and cortical penetration. Cerebral cortex disruption was systematically observed by us in invasive-type meningiomas and in 3 of 21 cases (14.3%) in transitional-type meningiomas. No penetration was observed in smooth-type meningiomas.

Peritumoral Edema in Meningiomas

Although generally benign tumors, meningiomas may be associated with extensive peritumoral brain edema as seen on computed tomographic scans. Fifty-two patients with intracranial meningiomas were studied, and the hypodense areas on computed tomographic scans were related to the intraoperative microsurgical findings and to the sizes of the tumors. We have identified three kinds of tumor-brain interfaces characterized by different difficulties in microsurgical dissection: smooth type, transitional type, and invasive type. These different microsurgical interfaces seem to correlate very precisely with computed tomographic images of halo-like and finger-like hypodense areas, allowing prediction of the microsurgical effort to be made in the surgery of meningiomas. The size of the tumor seems to be important in our subjects in determining the amount of edema produced. Indeed, a positive correlation (P < 0.001) was found between the sizes of the tumors and the extent of peritumoral hypodensity. A positive correlation (P < 0.002) also has been found between grade of edema and cortical penetration. Cerebral cortex disruption was systematically observed by us in invasive-type meningiomas and in 3 of 21 cases (14.3%) in transitional-type meningiomas. No penetration was observed in smooth-type meningiomas.

Could nanoparticle systems have a role in the treatment of cerebral gliomas

UNLABELLED Malignant brain tumors are difficult to manage clinically and are associated with high rates of morbidity and mortality. Late diagnosis and the limitations of conventional therapies that may result from inefficient delivery of the therapeutic or contrast agent to brain tumors due to the blood-brain barrier and nonspecificity of the agents, are major reasons for this unsolved clinical problem. Nanotechnology involves the design, synthesis, and characterization of materials and devices that have a functional organization in at least one dimension on the nanometer scale. The nanoparticle has emerged as a potential vector for brain delivery, able to overcome the difficulties of modern strategies. Moreover, multifunctionality can be engineered into a single nanoplatform so that it can provide tumor-specific detection, treatment, and follow-up monitoring. This review reports the latest research in nanoparticle-based glioma treatment. FROM THE CLINICAL EDITOR In recent years, nanoparticles have emerged as potential delivery vectors targeting brain tumors, including multifunctional NP-s allowing tumor-specific detection, treatment, and follow-up monitoring. This review summarizes the latest research in nanoparticle-based glioma treatment.

Radiation-Induced Blood-Brain Barrier Changes: Pathophysiological Mechanisms and Clinical Implications

The pathophysiology of whole-brain radiation (WBR) toxicity remains incompletely understood. The possibility of a primary change in blood-brain barrier (BBB) associated with microvascular damage was investigated. Rats were exposed to conventional fractionation in radiation (200 +/- cGy/d, 5d/wk; total dose, 4,000 cGy). BBB changes were assessed by means of the quantitative 14C-alpha-aminoisobutyric acid (AIB) technique coupled with standard electron microscopy (EM) and morphometric techniques as well as studies of the transcapillary passage of horseradish peroxidase (HRP). At 15 days after WBR, AIB transport across BBB increased significantly in cerebral cortex. EM disclosed vesicular transport of HRP across the intact endothelium without opening of the tight junctions. Ninety days after WBR, well-defined alterations of the microvasculature were observed. The main feature of cortical microvessels was their collapsed aspect, associated with perivascular edema containing cell debris. Data suggest a possible association between damage of the microvascular/glial unit of tissue injury and development of radiation-induced brain cerebral dysfunction. We hypothesize the following sequence of pathophysiological events: WBR causes an early increase in BBB permeability, which produces perivascular edema and microvascular collapse. The interference with microcirculation affects blood flow and energy supply to the tissue, resulting in structural damage on an ischemic/dysmetabolic basis.

Nanotechnology Platforms in Diagnosis and Treatment of Primary Brain Tumors

Despite aggressive multimodal strategies, the prognosis in patients affected by primary brain tumors is still very unfavorable. Glial tumors seem to be able to create a favorable environment for the invasion of neoplastic cells into the cerebral parenchyma when they interact with the extracellular matrix via cell surface receptors. The major problem in drug delivery into the brain is due to the presence of the blood brain barrier which limits drug penetration. Nanotechnology involves the design, synthesis and characterization of materials that have a functional organization at least in one dimension on the nanometer scale. Nanoengineered devices in medical applications are designed to interface and interact with cells and tissues at the molecular level. Nanoparticle systems can represent ideal devices for delivery of specific compounds to brain tumors, across the blood brain barrier. In this brief review, we report the results of studies related to the emerging novel applications of nanoparticle systems in diagnosis and treatment of primary brain tumors, and also the patents of studies that adopt nanoparticle systems as drug delivery carriers in brain tumor diagnosis and therapy.

Transsphenoidal microsurgical selective removal of multiple (triple) adenomas of the pituitary gland.

Summary This is the first case of multiple (triple) pituitary micro-adenomas documented by magnetic resonance imaging (MRI) in a living patient and treated by a transsphenoidal microsurgical approach. The patient, a 37-year-old woman, complained of a long history of bifrontal headache, weight gain and oligomenorrhea. Physical examination revealed moderate hirsutism and a slight fat pad overlying the vertebrae. Routine laboratory studies and endocrinological biochemical investigations were normal. A gadolinium-enhanced MRI of the pituitary region revealed three intrapituitary micro-adenomas. A transsphenoidal microsurgical approach to the pituitary gland was carried out and micro-adenomas were completely removed one at a time. One year follow-up showed complete resolution of clinical symptoms and signs and normal biochemical parameters of pituitary function.

Spinal Cord Compression by a Metastasizing Thymoma

Thymomas are rare slow growing tumours, which arise from thymic parenchyma and are characterised by local invasiveness. They represent 20% of all malignant mediastinal tumours. Based on the ratio of thymic versus epithelial elements, thymomas have been classi®ed into epithelial, lymphocytic, mixed and spindle cell types [3]. Currently, the Masaoka classi®cation is the most widely used staging system [4]. Approximately one-third of patients with thymoma has Myasthenia Gravis (MG), and one-tenth of patients a ̈ected by MG has a thymoma. The presence of MG adversely a ̈ects survival in some series but not in others. Invasive thymomas with a greater component of epithelial cells and association with MG have a poor prognosis. Only seven cases of metastases to the spinal cord have so far been described in the literature [2].

Do Spinal Meningiomas Penetrate the Pial Layer? Correlation between Magnetic Resonance Imaging and Microsurgical Findings and Intracranial Tumor Interfaces

OBJECTIVE To study the relationships between spinal dura-arachnoid and tumor-cord interfaces in spinal meningiomas and to investigate whether a disruption of the pial layer and penetration of the tumor in the spinal cord occurs. METHODS Fifteen patients with histologically proven meningiomas underwent magnetic resonance imaging (MRI) preoperatively. All patients underwent microsurgery. The histological characteristics of the tumors were compared with MRI and microsurgical findings. RESULTS At surgery, the peritumoral hypointense rim revealed by MRI in 10 of 15 patients corresponded to a well-defined cerebrospinal fluid-containing space confined between the outer arachnoidal layer and the inner leptomeningeal layer. In those patients in whom the hypointense peritumoral rim was absent, the inner layer was either difficult to identify or clearly absent, and the blood vessels were extremely adherent to the tumor, requiring a more cautious dissection. Penetration of the tumors through disruption of the pial surface was not documented. CONCLUSION Previous anatomic and electron microscopy studies demonstrated, in human spinal meninges, the presence of an intermediate layer attached to the inner aspect of the arachnoid, extending laterally over the dorsal surface of the spinal cord and arborizing over the nerve roots and blood vessels. The intermediate layer is not present in human cerebral leptomeninges. The presence/absence of this layer might explain the hypointense rim detected by MRI and might also explain why no penetration and no peritumoral edema is observed in spinal meningiomas as compared with intracranial meningiomas.

The Reference System: The ca-cp Plane

Talairach (1955) and Schaltenbrandt (1977) suggested that the anterior and posterior commissure might be considered to have a constant relationship with the deep cerebral structures and proposed using a line between these two structures as the basic reference line. Talairach found only a negligible difference between the intercommissural distance in 26 brains (from 23 mm to 28.5 mm) and took the average of this distance as 25.5 mm in his proportional atlases (Talairach 1957,1988,1993).

Magnified 2D Plate Reconstructions

Spatial Limits and Magnification Factors In the atlas, the spatial limits of 2D area reconstructions are given, taking into account the extension of the principal deep brain nuclei and their relationships with the ventricular system: [1] 1. Anteriorly in the more frontal part of the head of caudate nucleus, about 27 mm from the anterior commissure [2] 2. Posteriorly tangential to the collicular plate, about 39 mm from the anterior commissure [3] 3. Superiorly in the more cranial part of the body of caudate nucleus, about 27 mm above the intercommissural plane [4] 4. Inferiorly tangential to the lower part of the pituitary gland, about 21 mm below the intercommissural plane [5] 5. Laterally tangential to the internal part of the lobus insularis, about 39 mm from the intercommissural plane [6] 6. Medially on the midline