Microvessel Organization and Structure in Experimental Brain Tumors: Microvessel Populations with Distinctive Structural and Functional Properties

One hundred and one cases of clinical prostatic carcinoma (PCa), primary site, were analysed to define the inter-relationship between tumour angiogenesis, histological grade, and bone marrow metastasis. Tumour angiogenesis was determined by the blood capillary density ratio (BCDR; a/b), defined as the ratio between the area of the blood capillaries (a) and the area of the tumour (b). The BCDR was evaluated by a colour image analysis system employing a computerized morphometrical method. A total of 43 cases of PCa with bone marrow metastasis (stage D2) and 58 cases of PCa without metastasis (stage B, C) were utilized. The prostatic carcinomas were classified into three groups (low, intermediate, and high) using Gleason's grading system. 1The BCDR of the primary PCa with bone marrow metastasis was similar in each of the three histologically graded scores. On the other hand, in the cases of PCa without metastasis, the BCDR of high score PCa was higher than those of the low and intermediate score PCa (U-test; P<0·001). The BCDR of the high score PCa without metastasis was similar to that of the PCa with bone marrow metastasis. The BCDR may provide help in predicting tumour progression with regard to bone marrow metastasis of PCa with low and intermediate Gleason's scores.

Tumour angiogenesis in prostatic carcinoma with and without bone marrow metastasis: a morphometric study.

Histopathologic evaluation of glioblastoma multiforme (GBM) at initial diagnosis is typically performed on tissue obtained from regions of contrast enhancement (CE) as depicted on gadolinium-enhanced, T1-weighted images. The non-enhancing (NE) portion of the lesion, which contains both reactive edema and infiltrative tumor, is only partially removed due to concerns about damaging functioning brain. The purpose of this study was to evaluate histopathologic and physiologic MRI features of image-guided tissue specimens from CE and NE regions to investigate correlations between imaging and histopathologic parameters. One hundred nineteen tissue specimens (93 CE and 26 NE regions) were acquired from 51 patients with newly diagnosed GBM by utilizing stereotactic image-guided sampling. Variables of anatomic, diffusion-weighted imaging (DWI), and dynamic susceptibility–weighted, contrast-enhanced perfusion imaging (DSC) from each tissue sample location were obtained and compared with histopathologic features such as tumor score, cell density, proliferation, architectural disruption, hypoxia, and microvascular hyperplasia. Tissue samples from CE regions had increased tumor score, cellular density, proliferation, and architectural disruption compared with NE regions. DSC variables such as relative cerebral blood volume, peak height, and recovery factor were significantly higher, and the percentage of signal intensity recovery was significantly lower in the CE compared with the NE regions. DWI variables were correlated with histopathologic features of GBM within NE regions. Image-guided tissue acquisition and assessment of residual tumor from treatment-naive GBM should be guided by DSC in CE regions and by DWI in NE regions.

Regional variation in histopathologic features of tumor specimens from treatment-naive glioblastoma correlates with anatomic and physiologic MR Imaging

Our findings suggest that the heterogeneous genetic and cellular expression patterns within glioblastoma multiforme, in part, influence anatomic and physiologic MR imaging.

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Glioblastoma multiforme regional genetic and cellular expression patterns: influence on anatomic and physiologic MR imaging.

Structural and functional abnormalities of the vascular microenvironment determine pathophysiological characteristics of gliomas, such as loss of blood-brain barrier function, tumor cell invasiveness, or permselectivity for large molecules. Moreover, the effectiveness of various therapeutic strategies critically depends upon the successful transvascular delivery of molecules. In order to shed more light on the vascular microenvironment in gliomas, a variety of experimental and clinical techniques have been applied to study the glioma microvasculature, including histology, vascular corrosion casts, microangiography by injection of dyes, blood flow measurements by autoradiography, tracer washout techniques, magnetic resonance imaging, as well as intravital fluorescence microscopy. This review summarizes the characteristic features of vascular morphology, angio-architecture, tumor perfusion, microvascular permeability, as well as microvessel-related immunological competence in gliomas. An improved understanding of the vascular microenvironment in gliomas will help in the future to optimize glioma imaging and delivery of vectors for gene therapy or encapsulated drug carriers in patients.

P L Lantos

Papers

The vasculature of experimental brain tumours: Part 2. A quantitative assessment of morphological abnormalities