Multiparameter flow cytometric analysis of neoplasms of the central nervous system: correlation of nuclear antigen p105 and DNA content with clinical behavior

Analysis of the DNA content of various solid tumors and hematological malignancies may provide useful prognostic information. To date, however, there has been a striking lack of correlation between DNA content in neoplasms of the central nervous system and clinical behavior. Simultaneous quantitation of DNA content and proliferation-associated nuclear antigen (p105) by flow cytometry was performed on paraffin-embedded tissues representing three major groups of central nervous system neoplasms--1) 21 astrocytic tumors, 2) 13 pituitary tumors, and 3) 19 meningiomas--and the results were correlated with clinical behavior. All 4 well-differentiated gliomas were diploid, while 3 of 9 anaplastic astrocytomas and 1 of 8 glioblastomas had a demonstrable aneuploid peak. Three of 13 pituitary tumors had an identifiable aneuploid peak, while only 2 of 19 meningiomas had an aneuploid DNA content. Cell-cycle analysis of the malignant gliomas revealed a significantly higher proliferative index (PI, %S + G2M) compared with the well-differentiated astrocytomas (P less than 0.05). Within the subgroup of diploid anaplastic astrocytomas, however, extended patient survival appeared to be associated with a higher PI. For diploid pituitary adenomas, the PI was consistently lower in the 3 tumors that recurred than it was in the remaining 8 adenomas. Nuclear antigen quantitation of diploid tumors showed a wide range of p105 expression in G0G1 cells, suggesting that, within each tumor, the cells are heterogeneous with respect to proliferative activity. Aneuploid nuclei of glial tumors showed enhanced expression of p105 relative to diploid cells of the same specimen. In pituitary tumors, the median G2M/G0G1 fluorescence ratio for p105 was significantly higher (P less than 0.05) for the 3 diploid recurrent tumors than for those that did not recur. These data support the assumption that the aggressive clinical course of malignant glial neoplasms may be related to an abnormal DNA stemline and/or an alteration in cell proliferative activity. Cell cycle analysis and measurement of p105 by this technique may provide information useful from both a prognostic standpoint and in directing adjuvant therapy.

Histological, ultrastructural and chromatographical discrimination of phospholipids in meningiomas

Phospholipids in meningiomas were studied by light and electron microscopy, and by high-performance liquid chromatography. They were microscopically demonstrated in six of the ten cases by Sudan III staining after the fixation with potassium dichromate. However, the conventional ultrastructural fixation with glutaraldehyde and osmium tetroxide failed to confirm phospholipids, as most of them were dissolved during dehydration. In contrast, the specimens pretreated with tannic acid before osmication ultrastructurally retained phospholipids which were represented by multilamellar bodies or ribbon-like rings. Both were found in 23 of the 30 cases within the cytoplasm, among the plasma membranes and in the extracellular matrices. The outermost lamella or ribbon showed a direct continuity from the neighbouring plasma membranes of the cytoplasm or the mitochondria. The multilamellar bodies showed an overall distribution, while the ribbon-like rings were predominantly distributed around the psammoma bodies. Precipitation of hydroxyapatite crystals within the ribbon-like rings resulted in matrix minerals of psammoma bodies. Chromatographical analyses of meningiomas disclosed phospholipids including phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl serine, sphingomyelin and phosphatidyl inositol in that order. Psammomatous meningiomas contained a higher percentage of phosphatidyl serine than non-psammomatous tumors. Ultrastructural study of synthetic phospholipids adequately treated with tannic acid showed that the multilamellar bodies were similar to phosphatidyl choline, while the ribbon-like rings were similar to phosphatidyl serine. The role of phospholipids in meningiomas is discussed.

Soft-tissue and meningeal hemangiopericytomas: an immunohistochemical and ultrastructural study

The debate on the nosologic position of hemangiopericytomas of the meninges has been based mainly on light microscopic and ultrastructural considerations; recent immunohistochemical studies have yielded controversial results. We have used a panel of antibodies to vimentin, desmin, actin, S100 protein, epithelial membrane antigen, cytokeratins, Leu-7, factor VIII-related antigen and type IV collagen to compare the immunophenotype of 10 soft-tissue and seven meningeal hemangiopericytomas. The immunophenotypic profile of these tumors is identical, and differs from that of meningiomas in that epithelial membrane antigen and cytokeratin are not present. The vascular pattern occurring in some meningiomas can simulate true hemangiopericytomas of the meninges. Immunohistochemical studies should allow their distinction in each instance. Meningeal and soft-tissue hemangiopericytomas display similar ultrastructural features.

[Differential immunohistochemical characteristics of meningiomas and other neoplasms of the central nervous system]

We present an immunohistochemical study of 16 meningiomas and 19 CNS tumors including gliomas, neurinomas and metastatic carcinomas, in order to establish a histopathologic differential diagnosis, using formalin-fixed and paraffin-embedded material. The antibodies analysed included vimentin, GFA-protein, cytokeratin, S-100 protein and epithelial membrane antigen. Meningiomas always express vimentin as marker, and occasionally cytokeratin and EMA. The most constant antigens demonstrated in astrocytomas were GFA-protein and vimentin, and occasionally we were able to detect S-100 protein. Neurinomas proved positive to S-100 protein, and metastases presented cytokeratin and EMA reactivity. Our results confirm the existence of diverse immunohistochemical patterns within CNS tumors, a fact that can be useful in routine differential diagnosis.

Steroid hormone and epidermal growth factor receptors in meningiomas

A prospective study of steroid hormone and epidermal growth factor receptor expression in 57 meningiomas is presented. Scatchard analysis of radioligand binding identified 20% of meningiomas as expressing classical oestrogen receptors (ER) at levels below that normally accepted for positivity, the remainder being negative. ER could not be visualized in any meningioma using immunocytochemistry. Alternatively, 74% of meningiomas demonstrated the presence of progesterone receptors (PR) by Scatchard analysis, the specificity of which could not be attributed to glucocorticoid or androgen receptors. Confirmation of classical PR presence was determined by immunocytochemical staining. The presence of epidermal growth factor receptor (EGFR) was demonstrated in 100% of meningiomas using immunocytochemical staining. These data are reviewed in the context of previously reported results and are discussed in relation to the potential for medical therapy as an adjunct to surgery.

Ganglioside composition in human meningiomas

The ganglioside composition in meningioma specimens from 20 patients was analyzed to find potential meningioma-associated structures. The characterization was performed by immunological staining with specific monoclonal antibodies to ganglioside antigens and fast atom bombardment-mass spectrometry. The major gangliosides were GM3 and GD3, and most of the meningioma specimens could be divided into a "GM3-rich" or a "GD3-rich" group. Gangliosides of the gangliotetraose series were represented by GM1, GD1a, GD1b, and GT1b, which were found in minor amounts in all the specimens. The ratios of GM1/GD1a and GD1a/GD1b differed from that in normal brain, and therefore existence of this series could not be explained by contamination with brain material. Ganglioside 3'-isoLM1, found in human malignant glioma, could not be detected in any meningioma specimen.

Epithelial differentiation in meningiomas. An immunohistochemical, histochemical, and ultrastructural study--with review of the literature

Meningiomas possess features indicative of epithelial differentiation. The present study further documents this finding by a multimodality approach on serial sections from 25 meningiomas of all histologic and clinical categories. Standard light microscopic examination, immunohistochemical staining with a variety of epithelial and nonepithelial markers, and histochemical staining for mucin were performed on each case. Directed electron microscopic examination was performed on selected examples of epithelial feature-positive and -negative cases. All cases were immunoreactive for vimentin and epithelial membrane antigen. Thirty-two percent were reactive for cytokeratin and 39% for S-100. Twenty percent showed mucin positivity by histochemistry. Electron microscopic examination of cytokeratin-positive cases showed either intracellular lumina (secretory areas) or cytoplasmic tonofibrils, whereas cytokeratin-negative tumors lacked lumina and tonofibrils. Previous studies showing epithelial features in meningiomas are reviewed with emphasis on the studies using immunohistochemistry. These histochemical, immunohistochemical, and ultrastructural characteristics are of utility in the examination of tumors of suspected meningeal origin, particularly when dealing with atypical presentations or histomorphologic features.

Noninvasive differentiation of tumors with use of localized H-1 MR spectroscopy in vivo: initial experience in patients with cerebral tumors

A recently developed method for image-selected localized hydrogen-1 magnetic resonance (MR) spectroscopy was assessed in the differential diagnosis of nine primary and secondary cerebral tumors, including four gliomas, two meningiomas, one neurilemoma, one arachnoid cyst, and one metastasis of breast cancer. Well-resolved H-1 MR spectra of these tumors were obtained in vivo with a conventional 1.5-T whole-body MR imaging system. All tumor spectra were remarkably different from spectra from normal brain tissue. Spectra obtained from different tumors exhibited reproducible differences, while histologically similar tumors yielded characteristic spectra with only minor differences. The observed spectral alterations reflect variations in concentrations and relaxation times of the H-1 MR sensitive pool of free (mobile) metabolites within the tissues. In most cases, the concentrations of N-acetyl-aspartate and creatine/phosphocreatine are reduced below detectability, whereas choline-containing compounds are generally enhanced. The spectral differences between the tumors are mainly due to the differing concentrations of lipids, lactic acid, and carbohydrates. Localized H-1 MR spectroscopy may become an important clinical tool for the differentiation of tumors as well as for therapeutic control.

Immunocytochemical identification of meningeal leukemia and lymphoma: poly-L-lysine-coated slides permit multimarker analysis even with minute cerebrospinal fluid cell specimens

Use of immunocytology for accurate identification of malignant cells in cerebrospinal fluid (CSF) has so far been hampered by high cell requirements of the immunologic methods hitherto used. In an attempt to minimize cell loss in cytopreparation, electrostatic binding of cells to poly-L-lysine (PLL)-coated multispot slides, followed by immunocytochemistry, was investigated. Using optimized conditions of cell attachment and fixation and performing all washing procedures on the slide made multimarker analysis possible even in paucicellular specimens, while preserving excellent cell morphology and yielding high sensitivity in the detection of antigens. In a study of 26 CSF specimens with inconclusive cytomorphology, comprising 335 single marker determinations, we were able to discriminate reliably between resting or activated benign cells and a wide range of types of malignant lymphoid cell. A definitive diagnosis was reached in all cases by one tap only. Malignant meningitis was ruled out in ten specimens and proved in 16, including five in which the type of malignancy could only be determined by immunophenotyping. We conclude that immunocytochemistry on PLL-coated slides constitutes the method of choice for immunologic cell differentiation in CSF, which allows equivocal morphologic findings to be clarified.

Rapid growth of a meningioma during pregnancy: relationship with estrogen and progesterone receptors--case report

Meningiomas are often described as hormone-dependent because of their preponderance in females and their tendency to clinically manifest during or after pregnancy. We describe a case of meningioma that grew rapidly during two pregnancies over a 2-year period. The tumor's rapid growth was confirmed by high-resolution computed tomography. Its estimated doubling time was 110 days. The tumor was removed and found to be a benign meningothelial meningioma. The tumor tissue was positive for estrogen receptors (ERs) and progesterone receptors (PRs). In nine cases, including this one, in which ERs and PRs were measured, the positive rate was much higher for PRs than for ERs; only two were positive for ERs. In the case reported here, it is presumed that the growth of the meningioma was influenced by estrogen and/or progesterone binding to receptors, although it is unclear whether one or both hormones was involved.

[Assessment of the estrogen and progesterone receptor status of meningiomas. A preliminary study of 10 cases]

Ten cases of intracranial meningiomas in patient who differed by age, sex and histological characteristics of the lesion have been considered for the purpose of evaluating the lesion's receptor capacity and the changes in it with the above variations. Receptors were found and they varied with age and histological features.

[Estrogen receptors in patients with brain tumors]

Estrogen receptor (ER) of brain tumors was assayed in 45 patients. In this series there were 39 cases contained ER, ranged from 0.7 to 188 fmol/mg protein of tumors (mean: 16.1 fmol/mg). The mean level of ER was 10.3 fmol/mg in 20 cases with meningiomas, 8.4 fmol/mg in 11 cases with gliomas, 51.1 fmol/mg in 5 cases with neurilemmomas, 10.5 fmol/mg in 3 cases with medulloblastomas, 16 fmol/mg in 2 organized hematomas due to ruptured AVM, 5.7 fmol/mg in a chordoma, 3.9 fmol/mg in a metastatic carcinoma from thyroid gland, and 0.8 fmol/mg in a cholesteatoma. The presence of ER in the latter several kinds of brain tumors have not been reported in previous literatures. The ER level of the tumors correlated with histological type of tumors, as well as the sex and age of the patients.

Meningioma, meningeal hemangiopericytoma (angioblastic meningioma), peripheral hemangiopericytoma, and acoustic schwannoma. A comparative immunohistochemical study

The relationship between meningeal hemangiopericytoma (angioblastic meningioma), meningiomas of meningothelial derivation, and peripheral hemangiopericytoma is controversial; and immunohistochemical studies have yielded conflicting results. Likewise, immunohistochemistry has been touted as a reliable means of differentiating fibrous meningioma from acoustic schwannoma. By the immunoperoxidase method, we studied 40 meningiomas (11 meningotheliomatous, four transitional, 11 fibrous, three secretory, four metaplastic, one xanthomatous, one papillary, four atypical, one malignant), five arachnoid granulations, 13 angioblastic meningiomas, nine peripheral hemangiopericytomas, and seven acoustic schwannomas. Antisera to vimentin, epithelial membrane antigen (EMA), keratin, S-100 protein, carcinoembryonic antigen (CEA), desmin, factor VIII, Ulex europeaus, and glial fibrillary acidic protein (GFAP) were utilized. All meningiomas and arachnoid granulations stained for vimentin and EMA; 15% and 12% of meningiomas were S-100 and keratin positive, respectively. The latter was noted primarily in areas of secretory (pseudopsammomatous) differentiation. In contrast, all angioblastic meningiomas stained for only vimentin. This profile of immunoreactivity was also seen in the peripheral hemangiopericytomas, with the exception of single cases that stained focally for EMA and S-100 protein, respectively. Acoustic schwannomas all stained positively for S-100 protein, vimentin, and were variably reactive for EMA, a pattern not distinct from meningioma. We conclude that (a) meningiomas express both epithelial and mesenchymal markers as do arachnoid granulations, (b) that angioblastic meningiomas demonstrate only mesenchymal markers, (c) that angioblastic meningiomas express identical markers to peripheral hemangiopericytoma and should thus be considered a variant thereof, (d) among meningiomas, CEA and keratin appear to be relatively specific markers for the "secretory" variant, and (e) because of overlap in S-100 and EMA reactivity, these markers are unreliable in differentiating meningioma from acoustic schwannoma.

Flow-cytometric DNA analysis and immunohistochemical measurement of Ki-67 and BUdR labeling indices in human brain tumors

Cell proliferation potential was assessed by measuring the labeling indices of the monoclonal antibody Ki-67 and of 5-bromodeoxyuridine (BUdR), and the cellular deoxyribonucleic acid (DNA) content in 48 human brain tumors. The diagnostic and prognostic value of flow-cytometric DNA analysis was also evaluated using ethanol-fixed paraffin-embedded BUdR-labeled specimens; these were the same specimens as were used for measuring the BUdR and Ki-67 labeling indices. Both the Ki-67 and the BUdR labeling indices correlated with the degree of malignancy estimated from conventional histological preparations. The Ki-67 labeling index was 1.7 times greater than the BUdR labeling index. The relationship of DNA aneuploidy to the labeling indices or to morphology in cases of glioma was examined. All of the tumors with an aneuploid line corresponded to malignant glioma classified by histological criteria, although malignant glioma did not always show DNA aneuploidy. In addition, the cases with aneuploid lines showed high BUdR and Ki-67 labeling indices. The cell kinetic data, which indicate the biological character of tumors, allowed prediction of the prognosis of the patients with gliomas. In contrast, despite the presence of an aneuploid line, three of 13 meningiomas showed a benign histological pattern without an aggressive clinical course, and neither the Ki-67 nor the BUdR labeling index was high. These results indicate an unequivocal relationship between DNA aneuploidy and clinical behavior; in general, both labeling indices may prove to be objective indicators of the outcome of patients with brain tumors.

Immunocytochemical evidence of progesterone receptors in human meningiomas

The presence of progesterone receptors in meningioma tissue is demonstrated by use of highly specific monoclonal antibodies against the rabbit progesterone receptors which cross-react with human progesterone receptors in breast cancer cells, thus giving evidence of the existence of genuine progesterone receptors in human meningiomas.

Some differences in steroid receptors between meningeal and neuroepithelial tumors

In our study we evaluated the presence of steroid hormone receptors in a large series of endocranial tumors and investigated the possible correlations between receptor presence and levels and patient's age and sex. Our data indicate that steroid receptor behavior in the neoplasias considered is quite different from that observed in endocrine-related tumors, such as breast and endometrial cancer. Moreover, in neuroepithelial tumors an interesting difference between male and female subjects has been found regarding the receptor distribution in poor differentiated neoplasias.

Central nervous system involvement demonstrated by immunological study in prolymphocytic variant of chronic lymphocytic leukemia

A patient with the prolymphocytic variant of B cell chronic lymphocytic leukemia (CLL/PL) who developed meningeal leukemic involvement is reported. He had been diagnosed as having CLL/PL 2.5 years earlier, and treated successively with splenectomy, continuous chlorambucil and CHOP chemotherapy. While receiving the latter treatment, the patient developed persistent cephalalgia and vomiting, without signs of neurological focality. A lumbar puncture yielded a cerebrospinal fluid (CSF) showing lymphoid cells of prolymphocytic appearance and the immunological cell markers demonstrated the clonality of these cells. Intrathecal methotrexate and arabinosyl cytosine treatment was administered, this leading to the disappearance of the abnormal cells from the CSF and the resolution of the clinical symptoms.

Intracytoplasmic lumina in meningioma: an ultrastructural and immunohistological study

Three surgically removed meningotheliomatous meningiomas with hyaline inclusions or pseudopsammoma bodies were studied. Ultrastructurally, the lumina seemed to be predominantly intracytoplasmic, defined by a systemic unit membrane; they displayed abundant microvilli and contained granular or filamentous material, vacuoles, vesicular bodies, and lamellar structure. The cytoplasm surrounding the intracytoplasmic lumina was electron-dense and contained tonofilaments and desmosomal junctions. All three meningiomas showed expression of carcinoembryonic antigen, cytokeratin, and epithelial membrane antigen in the cells surrounding the hyaline bodies. Keratin, alpha-1-antitrypsin, and immunoglobulin M showed weak positive staining. There was widespread vimentin except in the cells with hyaline inclusions. Glial fibrillary acidic protein and S100 were negative. These results provide additional confirmation of immunohistochemical data that can serve as evidence for epithelial and secretory differentiation in meningiomas.

In vivo H-1 spectroscopy in humans at 1.5 T

Water-suppressed and section-selective proton (hydrogen-1) magnetic resonance (MR) spectra were recorded from human brain, leg muscle, liver, and heart with a 1.5-T imager. Signal from water was well suppressed, and resonances from several metabolites were consequently seen. The spectra from brains of healthy volunteers (n = 5) showed resonances from N-acetylaspartate, glutamine, aspartate, phosphocreatine/creatine, choline, taurine, and glycine. In five large brain meningiomas, resonances from N-acetyl-aspartate and phosphocreatine/creatine were either not visible or markedly decreased in intensity. The spectra from leg muscles of healthy volunteers showed resonances from protons in saturated fatty acyl chains, whereas resonances from unsaturated fatty acyl chains predominated in spectra from leg muscles of two patients with spina bifida. The spectra from livers of three healthy volunteers showed resonances from aliphatic and aromatic amino acids, choline, carnitine, and both saturated and unsaturated fatty acyl chains, and spectra from hearts of six healthy volunteers showed major resonances from phosphocreatine/creatine and taurine and smaller resonances from amino acids and fatty acyl chains.

Cellular blue nevus ("melanocytoma") of the spinal meninges: electron microscopic and immunohistochemical features

A primary cellular blue nevus (melanocytoma) of the spinal canal in a 21-year-old woman is reported. Light microscopic examination revealed a melanotic neoplasm with histological patterns resembling schwannoma, dermal nevi, and neuroblastic-like tumor. The ultrastructural features of the neoplastic cells were similar to those in dermal blue nevi and melanomas. There was no evidence of arachnoidal cell differentiation. Immunohistochemistry revealed positive reactions for S-100 protein and neuron-specific enolase in many cells and no reactions for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, 70-kD neurofilament protein, or Leu-7. Vimentin was strongly positive in the melanocytic cells as well as in the arachnoidal cells of involved meninges. The ultrastructural and immunohistochemical features support the nevoid nature of this tumor, which is frequently mislabeled as "melanotic meningioma."

Androgen receptors in meningiomas

Meningiomas have been hypothesized as being hormonally sensitive on the basis of epidemiologic, clinical, and laboratory evidence. Eight meningiomas were assayed and found to have androgen-binding protein. Three tumors were subjected to in vitro growth studies in varying concentrations of dihydrotestosterone (DHT). The growth of tumor 1 was unaltered. Tumor 2 demonstrated 9% to 10% growth (P less than 0.05) in all concentrations tested. Tumor 3 revealed an 11% stimulation, but only in the lowest concentration of DHT tested. The small quantity, saturability, and in one tumor, high binding affinity, suggest this binding protein is a receptor. The in vitro response of these meningiomas was small and was not dose-related or proportionate to receptor quantity. Androgens do not appear to play as important a role as progesterone or estrogen in meningioma growth in vitro.

Protein analysis of subdural hygroma fluid

The pathogenesis of posttraumatic subdural hygroma still remains largely unknown. One of the suggested pathological mechanisms is the traumatic development of an arachnoid tear and the subsequent efflux of CSF into the subdural space. We performed a multifactorial analysis of the hygroma fluid obtained at operation in comparison to the simultaneously taken plasma and lumbar CSF. The results of the protein analysis support the CSF origin of the subdural hygroma fluid.

Gamma-enolase and glial fibrillary acidic protein in nervous system tumors. An immunohistochemical study using specific monoclonal antibodies

A large series of central and peripheral nervous system tumors was studied for the presence of glial fibrillary acidic protein (GFAP) and gamma-enolase (neuron-specific enolase, NSE), using specific monoclonal antibodies (mAbs). Occurrence in and specificity of GFAP to glial and mixed tumors was confirmed and depended on the malignancy grade and features such as meningeal invasion. Using a well-characterized mAb, gamma-enolase was demonstrated in neuronal, as well as in a whole range of non-neuronal tumors. This lack of specificity of gamma-enolase prohibits its use as an exclusive neuronal marker. Nevertheless quantization or comparison with other types of enolases could still prove to be useful in well-defined situations. The advantages inherent to mAbs and a highly sensitive detection system turn GFAP stainings into a specific and readily reproducible technique.

Immunohistochemical characteristics of haemangiopericytic meningiomas: comparison with typical meningiomas, haemangioblastomas and haemangiopericytomas from extracranial sites

The relationship between malignant vascular meningeal tumours and typical meningiomas remains controversial, despite the need for accurate diagnostic distinction between the two, and some forms of vascular meningioma may be more closely allied to haemangioblastomas or extracranial haemangiopericytomas than to true meningiomas. In order to try to clarify the diagnostic characteristics and origins of the entity known as haemangiopericytic meningioma, 10 histologically typical cases were stained by the immunoperoxidase technique with a panel of seven antibodies. The results were compared with those obtained from typical and angiomatous meningiomas, haemangioblastomas and haemangiopericytomas from extracranial sites. Both the haemangiopericytic meningiomas and the extracranial haemangiopericytomas showed a similar staining pattern, which differed from that of the typical and angiomatous meningiomas in the strikingly focal nature of the vimentin staining and the lack of reactivity with antibodies to epithelial elements. The haemangioblastomas were less consistent in their individual staining characteristics, but had a quite different overall pattern from all the other tumour types. It is, therefore, suggested that so-called haemangiopericytic meningiomas are in fact primary haemangiopericytomas of the meninges, antigenically distinct from true meningiomas and displaying a malignant potential appropriate to haemangiopericytomas arising in any other sites.

Sex hormone receptors in intracranial tumours and normal brain

Fifty-four intracranial neoplasms (29 meningiomas, 16 gliomas, seven acoustic neuromas and two cerebral metastases) and nine specimens of normal brain were evaluated for specific progesterone and oestrogen receptor proteins using a dextran-coated charcoal assay and Scatchard plot analysis. Sixteen meningiomas (55%) were progesterone receptor (PgR) positive (median 52; mean 120; range 10-486 fmol mg-1 cytosol protein), whilst all were oestrogen receptor negative (ER-). Two (28%) of the acoustic neuromas contained small amounts of PgR protein, but all seven were ER-. None of the gliomas, cerebral metastases or specimens of normal brain contained ER or PgR protein. Analysis of PgR status and clinicopathological data suggest that there is no predictive correlation between PgR status and the patients age, sex, reproductive status, tumour histology or tumour behaviour. These results again suggest that in meningiomas PgR proteins are not modulated by oestrogens acting through ER. This finding may explain the failure of antioestrogen therapy to influence the growth of meningiomas. The significance of PgR protein in intracranial meningiomas is discussed with respect to tumour heterogeneity and implications for research with gene probes.

Meningiomas and arachnoid cells: an immunohistochemical study of epithelial markers

Twenty-nine cases of meningioma were studied by immunoperoxidase staining using broad-spectrum antibodies to cytokeratin (AE1/AE3), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Twenty-six cases (90%) showed positive staining for EMA. All cases were negative for cytokeratin and CEA except for the two cases of secretory meningioma. Normal arachnoidal cells of the leptomeninges from 15 autopsies were studied similarly, and 10 cases (67%) demonstrated positive staining for EMA, but not for CEA and cytokeratin. Literature from previous investigations on epithelial markers of meningiomas is reviewed. It is concluded that meningiomas and normal arachnoidal cells share similar immunohistochemical properties, and that EMA is a useful epithelial marker for meningiomas.

Gonadal steroid receptors in meningiomas

Oestrogen receptor (ER) analysis was performed in 70 meningiomas with an enzyme immunoassay, using monoclonal antibodies against human oestrogen receptor protein (oestrophilin) and with a sensitive radioligand binding assay, using 125I-oestradiol as radioligand. Low levels of ER immunoreactivity were found in tumours from 51% of patients, whereas ER binding activity was demonstrated in 40% of the meningiomas examined. In 8 (11%) tissue samples multiple binding sites for oestradiol were observed. The immunoreactive binding sites corresponded to the classical, high-affinity ER. In ligand binding studies, however, measurement of classical ER was considerably influenced by a second low-affinity, high-capacity oestrogen binding component even at low ligand concentrations. 3H-methylpromegestone and 3H-methyltrienolone, a synthetic gestagen and androgen, were used for concurrent determination of the progesterone receptor (PR) and androgen receptor (AR) binding activity. High concentrations of PR were detected in 53 (76%), whereas moderate levels of AR binding sites were demonstrated in 33 (47%) tumours. A positive correlation between ER immunoreactivity and AR binding activity is indicative for an oestrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency for a dependence of receptor concentrations on the histological subtype could have implications for tumour therapy.

[Immunohistochemical study of human brain tumors with vimentin and astroprotein (GFAP)]

Distributions of two different subclasses of intermediate filaments, vimentin and glial filaments, were studied immunohistochemically in human brain tumors using specific antiserum to each protein subunit, vimentin and astroprotein (GFAP), Surgical specimens (5 meningiomas, 4 ependymomas, 5 benign astrocytomas, 5 anaplastic astrocytomas and 7 glioblastomas) were fixed in 95% ethanol or ethanol-acidic acid (95:5) and embedded in paraffin Avidin biotin peroxidase-complex (ABC) method (Vectastain) was carried out on 6 microns-thick paraffin sections. All meningioma cells were negative for astroprotein (GFAP) and positive for vimentin. Ependymoma cells showed various patterns of immunoreaction for astroprotein (GFAP) but were invariably positive for vimentin. In benign astrocytomas, many cells (or cell body and processes) were positive for astroprotein (GFAP). Immunoreaction for vimentin was, however, less frequent and intense. In anaplastic astrocytomas, population of astroprotein (GFAP)-positive cells decreased and vimentin-positive cells increased. Astroprotein (GFAP)-positive cells were further decreased in glioblastomas and the population of vimentin-positive cells varied among tissues. The present study suggests that the anaplastic change of astrocytoma cells were associated with decreased expression of glial filaments and increased expression of vimentin filaments. It was also suggests that the expression of both intermediate filaments may be suppressed in highly-malignant glial tumor cells.

Simultaneous isolation of high molecular weight RNA and DNA from limited amounts of tissues and cells

A simple method is described for the simultaneous isolation of both DNA and RNA from tissues and cultured cells obtainable in limited quantities only. The method is based on a suitable combination of steps designed for preparations of high molecular weight nucleic acids in cases when restricted amounts of tissues like small-sized and unique biopsies of tumors are available for studies of gene organization and expression. Using this protocol, undegraded total RNA suitable for Northern blot analysis and high molecular weight DNA for Southern blots was obtained from various sources (mammary and colon carcinomas, meningiomas, colonic and placental tissue, and several cell cultures).

Correlation of meningioma hormone receptor status with hormone sensitivity in a tumor stem-cell assay

Several investigators have detected progesterone receptors in a high percentage of meningioma specimens and have noted progesterone receptors to be more common than estrogen receptors in these specimens. However, a functional significance of such hormone receptor positivity in control of meningioma growth has not been described. This paper describes a paired test of the estrogen and progesterone receptor assay as the biochemical assay and of the human tumor stem-cell clonogenic assay (HTSCCA) as the functional assay in 17 meningioma specimens. Only one (6%) of the 17 specimens was estrogen receptor-positive, while 11 (69%) of 16 specimens were progesterone receptor-positive. The HTSCCA revealed that only two (15%) of 13 specimens were sensitive to estradiol while five (31%) of 16 specimens were sensitive to progesterone. Comparison of progesterone results for the 15 specimens on which both hormone receptor assay and HTSCCA were performed revealed correlation in a majority of cases; four specimens were positive for both assays and five specimens were negative for both assays. No specimen that was negative for progesterone receptors was sensitive to progesterone by HTSCCA. These results suggest that the hormone receptor and sensitivity pattern of meningiomas may differ from that of breast cancer, and that progesterone addition or ablation may be a reasonable therapeutic approach for meningiomas.

Distribution of extracellular matrix proteins in primary human brain tumours: an immunohistochemical analysis

Using immunohistochemical techniques, we localized several glycoproteins of the extracellular matrix in paraffin-embedded sections of 4 normal brain and 38 primary intracranial tumour specimens. All specimens were positively immunostained to various degrees by monoclonal antibodies to type IV collagen and procollagen III and by antisera to laminin and fibronectin. Staining was consistently most intense at sites of contact between neuroepithelial and mesenchymal or leptomeningeal elements; there was no demonstrable staining within or between neuroepithelial elements in the neuropil. Tumour cells from meningiomas and from the sarcomatous portion of a gliosarcoma were positively immunostained for fibronectin and laminin. The integrity of the glial limitans externa was demonstrated by the positive linear reaction product produced by immunostains for type IV collagen and laminin, even in the most malignant gliomas. The deposition of extracellular matrix glycoproteins at the glial-mesenchymal interface observed in this study of primary human brain tumours is a manifestation of one of the interactions between tumour and stromal cells in the central nervous system. A loss of coordination and an alteration in the interactions between epithelial cells and stromal cells across extracellular matrices such as basement membranes are thought to be fundamental steps in the development and progression of cancer. Further characterization studies focusing on other markers of the extracellular matrix are needed to elucidate completely the function of this structure in the central nervous system.

Estrogen and progestin receptors in intracranial tumors

Tissue samples from 17 intracranial tumors were analysed for the cytosolic estrogen and progestin receptor concentration. Three of the four meningiomas were progestin receptor-positive, but all were estrogen receptor-negative. All the four meningioma patients were postmenopausal women. The intracranial metastasis of a mammary carcinoma contained both estrogen and progestin receptors. Low progestin receptor concentration was found in an astrocytoma of a postmenopausal women. In addition, the presence of estrogen and progestin receptors was studied in four prolactinomas, two glioblastomas, two oligodendrogliomas, two mixed-cell carcinomas and one astrocytoma. All these tumors were estrogen and progestin receptor-negative.

Pathology of brain parenchyma in meningeal carcinomatosis; immunohistochemical study with astroprotein (GFAP) and tubulin

Effects of leptomeningeal tumor on the brain parenchyma was studied by the immunohistochemical method with astroprotein (GFAP) and tubulin in a rat model of meningeal carcinomatosis. Thickening of subpial glial lining (external glial layer) and hypertrophy of subpial astrocytes, detected by the antiserum to GFAP, was the early sign of parenchymal involvement. The glial lining was continuous as far as the tumor cells were confined to the subarachnoid space, however, penetration of tumor cells into subpial brain was associated with disruption of the glial lining. Speculative role of this lining in preventing the tumor cell to infiltrate into brain tissue was discussed. In contrast to the prominent immunohistochemical changes in astrocytes, neuronal tubulin immunoreactivity was not altered even in the late stage of the disease. The present study demonstrated that the leptomeningeal dissemination of tumor cells did cause pathologic change in brain parenchyma as was evidenced by the reactive change of astrocytes. However, the preserved immunoreaction for tubulin suggested that the nerve cell damage was not severe even at the advanced stage of the disease.

Topochemical demonstration of zinc in meningiomas

In agreement with the atomic absorption tests, histochemical demonstration of zinc in meningiomas using the dithizone method revealed a higher level of zinc in fibromatous meningiomas than in its meningiotheliomatous variant. Calcified psammoma bodies and vessels exhibited an intensely positive reaction on their surface. The metabolic function of zinc in the synthesis of fibre proteins, as well as in metallo-enzymes associated with mineralization, explains these findings.

[Flow cytometric and karyotypic studies on meningiomas]

Although meningiomas have been regarded as one of the benign brain tumors, cases showing clinically malignant behavior have been reported. For the purpose of detecting the possibility of predicting different biological behavior in meningiomas, eleven meningiomas were studied with the aid of flow cytometric (FMC) and cytogenetic techniques. Morphologically two cases were diagnosed as syncytial meningiomas and nine as transitional meningiomas. The former included one case (#5) of "syncytial poorly structured meningioma" (Zang et al.). In the FCM study seven out of eleven cases showed diploid (2C) or near diploid modal peaks with small amounts of tetraploid DNA (4C) cells. The remaining four cases had larger cell populations at 4C. Cytogenetically cells corresponding to 2C and near 2C peaks were also proved to be composed of diploid or hypodiploid cells in all of the eight cases studied. Chromosomal analyses revealed normal karyotypes in three. The remaining five hypodiploid cases had common chromosomal aberrations in G22, including missing chromosome 22 in four cases and 22 q-deletion in one. Nine cases grown in culture were also studied by FCM and were able to be maintained in culture from 14 days to 5 months. Close to the terminal stage of culture, most of the cases in culture tended to have higher cell population at 4C and the appearance of cells even at 8C (polyploidization). Similar changes were also obtained in cultured human fibroblast and seem not to be specific to this benign tumor. These results are discussed with reference to the previous reports from the point of view of patterns of FCM histograms from surgical specimens, degree of hypodiploidy, morphological behavior. Further studies, especially relating to basic cell kinetics are needed before clinical application can be made.

Simultaneous estradiol and progesterone receptor analysis in meningiomas

The availability of [125I]estradiol and [3H]R5020, a synthetic gestagen, have made it possible to determine estradiol and progesterone receptors simultaneously in 70 meningiomas with a double-labeling assay. With this technique, complete Scatchard analysis can be carried out for both receptors, even with small amounts of tumor tissue such as biopsy specimens. Low levels of estradiol receptor reactivity were found in 11%, whereas specific progesterone receptors were demonstrated in 76%, of the meningiomas examined. No correlation of receptor concentration with sex or age of the patients or with location of the tumor has yet been demonstrated. However, indications of a correlation between gestagen binding activity and histological subtypes were found. The presence of progesterone receptors in a large proportion of meningiomas could have implications for tumor therapy.

Search for estrogen receptors in human meningioma tissue sections with a monoclonal antibody against the human estrogen receptor

Meningiomas are rich in progestin receptors, whereas estrogen receptors (ER) are virtually undetectable. The present experiments were performed to evaluate whether the absence of ER from the majority of human meningioma cytosols can be attributed to: occurrence of only a small number of ER-positive cells in an otherwise ER-negative tissue; resistance of nuclear receptors to extraction; or impairment of steroid binding. Twenty-one specimens were selected from our total series of 67 meningiomas. Based on cytosol assays, five of these meningiomas were considered to be ER positive (10-42 fmol/mg protein) and five had marginal ER concentrations (4-9 fmol/mg protein), whereas the remaining tissues were ER negative. For comparison, human breast cancer tissues were used. Tissues were sectioned at 6 micron and stained immunocytochemically using a monoclonal antibody against the human ER. The breast cancer specimens showed specific nuclear staining in part of the tumor cells. The sensitivity of the immunocytochemical assay was found to be sufficient to detect staining in breast cancer tissues containing as little as 17 fmol ER/mg cytosol protein. No specific staining was observed in meningioma tissues. It is concluded that the majority of meningiomas are truly devoid of ER and that the estrogen binding agent detected in low concentration in some meningioma cytosols is immunologically different from the human breast cancer ER. The presence of progestin receptors in meningioma apparently does not require the continuous presence of ER.

Primary leptomeningeal ependymoblastoma. Case report

Ependymoblastoma is considered to be a primitive malignant glioma with ependymal differentiation. This rare tumor occurs in very early life and shows rapid growth and a diffuse infiltration through the leptomeningeal space. The tumor cells are highly immature, with numerous mitoses and multilayered ependymal rosettes. The ependymoblastoma described in this report was found in a 17-year-old girl. In spite of detailed clinical and postmortem examinations, no definite primary site was identified in the neuraxis. The lesion spread predominantly throughout the leptomeningeal space. Histological analysis strongly suggested that this tumor originated from a heterotopic glial nest in the subarachnoid space. The absence of immunohistochemical neural tissue markers, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, and neurofilaments ruled out neuronal or glial differentiation. The authors were unable to find any previous report of primary leptomeningeal ependymoblastoma.

An ultrastructural and immunocytochemical analysis of leptomeningeal and meningioma cultures

Using immunocytochemical methods, we localized several glycoproteins of the extracellular matrix to leptomeningeal cells and meningiomas in vitro. Three cell lines derived from normal human leptomeninges and seven from meningiomas were studied by indirect immunofluorescence to evaluate the cellular production of fibronectin, laminin, collagen type IV, and procollagen type III. All leptomeningeal cell lines stained intensely and uniformly for all matrix proteins; all meningioma cell cultures stained uniformly, but the intensity of staining varied considerably. After removal of the cells in culture adherent to glass with 25 mM ammonium hydroxide, indirect immunofluorescence demonstrated an exuberant residual extracellular residue enriched with fibronectin, laminin, collagen type IV, and procollagen type III. Electron microscopic examination of all leptomeningeal and meningioma cultures revealed desmosomes and dense tonofilament formation; in addition, granular, filamentous basement membrane-like material was abundant in the extracellular spaces of all cultures. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of the cell layer of two leptomeningeal and four meningioma cultures showed production of interstitial collagen types I and III; diethylaminoethyl (DEAE)-cellulose chromatography of the medium demonstrated preferential production of procollagen type I. Our findings show conclusively that normal arachnoid cells in vitro synthesize several of the collagen subtypes and may be responsible for the "fibrous response" of the leptomeninges to trauma, infection, or infiltration by tumor. The similarities between leptomeningeal cells and meningiomas demonstrated by electron microscopy and by indirect immunofluorescence support the notion that meningiomas are derived from arachnoid cells. The localization of various mesenchymal glycoproteins within the intra- and extracellular spaces and the ubiquity of specialized intercellular junctions suggest that leptomeningeal cells in culture have the potential to behave like both stromal and epithelial cells.

Sex steroid receptors in human meningiomas

Results of experiments on the presence of steroid receptors in a series of 67 meningioma tissues, which were derived from 64 patients are presented. All tissues were studied using dextran-coated charcoal adsorption and Scatchard plot analysis. Progestin receptors were present in a high concentration in more than 80% of the specimens. Very low concentrations of an oestrogen binding agent were found in a limited number of samples. Thus, most meningiomas contain high levels of progestin receptors in the virtual absence of oestrogen receptors. Relations were not observed between progestin receptor-content and the age and sex of the patients, or the location and the histological type of the tumour. The role and action of progestin on meningiomas is still unknown. The presence of progestin receptors, however, suggests that meningioma may be regarded as a true target tissue for progestins.

Hormone treatment of meningiomas: lack of response to medroxyprogesterone acetate (MPA). A pilot study of five cases

Medroxyprogesterone acetate (MPA) has been used in high doses as hormone treatment for metastatic breast cancer. We treated five intracranial meningiomas with MPA expecting that MPA would reduce the volume or decrease the growth rate. All five patients were postmenopausal women, aged 47 to 73 years. Before treatment, the growth rate of each tumour was assessed by two consecutive CT scans (CT 1 and CT 2). Tumours 1 to 4, histologically benign meningiomas, grew slowly as the tumour volumes were not found to increase in 21 to 45 months between CT 1 and CT 2. Tumour 5 was an anaplastic meningioma the rapid growth of which was evident in 8 weeks between CT 1 and CT 2. After CT 2, MPA was given 1,000 mg intramusculary once weekly for 17 to 29 weeks until CT 3 which showed the response. Tumours 1 to 4 had neither reduced in volume nor developed necroses, and tumour 5 continued its fast growth at the same rate as before.