Quantitative imaging of estrogen and progesterone receptors, estrogen-regulated protein, and growth fraction: immunocytochemical assays in 52 meningiomas. Correlation with clinical and morphological data

Quantitative imaging of estrogen receptors (ER's), progesterone receptors (PR's), estrogen-regulated protein (pS2), and growth fraction (Ki67) immunocytochemical assays were performed in 52 meningiomas. The results were correlated with clinical (age, sex, hormonal status, and tumor volume and location) and morphological (histological types and grades) data. The authors observed a lack of ER's in all meningiomas but the presence of PR's in 53% of these meningiomas. The immunoreactivity was restricted to tumor cell nuclei. The PR immunocytochemical assay was correlated with tumor location, histological type, histological grade, and pS2 immunocytochemical assay, but not with Ki67 immunocytochemical assay; high PR content was observed in cisternae, transitional, meningothelial, and low-grade meningiomas. Only 11 meningiomas showed more than 1% Ki67 immunoreactive nuclei. These meningiomas were usually located in the convexity and were of high histological grade. Estrogen-regulated protein immunoreactivity was observed in 34 meningiomas but the number of immunoreactive nuclei was low. The pS2 immunocytochemical assay was not related to clinicopathological features but was preferentially observed in PR-negative meningiomas. The results of this study are compared with those previously reported, and the function and regulation of PR's in meningiomas is discussed. The results indicate that 1) regulation of PR's and pS2 proteins in meningiomas differs from regulation in estrogen-dependent tissues such as breast or endometrium; 2) interruption of hormonal therapy in women presenting with a meningioma is not absolutely necessary; 3) meningiomas have different biological properties according to their clinicopathological features; and 4) future studies of hormonal clinical trials should be performed on well-defined meningioma subgroups.

Biological behaviour and morphological characteristics of a transplantable tumour (MM-KMY) derived from a malignant meningioma in an F344 rat

A subcutaneously transplantable meningeal tumour (MM-KMY) was derived from a spontaneous malignant meningioma which developed in the cerebellar meninges of a female F344 rat. MM-KMY was subjected to 25 serial passages in syngeneic male and female rats. The transplants grew in 8 weeks into a nodule with an average diameter of 5.7 cm and average weight of 125.2 g. MM-KMY possessed large cysts containing fluid and necrotic tissue. Metastases frequently occurred in the lungs of MM-KMY-bearing rats. Histologically, both the original tumour and MM-KMY consisted of round to fusiform neoplastic cells of varying size, with nuclear pleomorphism. Mitotic figures occurred frequently. MM-KMY cells were positive for vimentin. Ultrastructurally, the cells showed desmosome-like structures, interdigitating processes and cytoplasmic intermediate filaments, suggesting an arachnoid cell origin. Abnormal accumulations of hyaline droplets in renal tubular epithelial cells were frequently observed in MM-KMY-bearing rats, suggesting overload of low molecular proteins in the renal tubules. The droplets gave a faint immunoreaction for lysozyme. The relation between the appearance of renal tubular hyaline droplets and the growth of MM-KMY remains to be determined. MM-KMY may prove useful for studying the biological behaviour and morphogenesis of meningeal tumours.

Primary post-traumatic intraorbital meningioma

Intraorbital meningiomas are uncommon tumours that usually represent extension from a primary intracranial tumour. Trauma has been proposed by Cushing and Eisenhardt as an etiologic factor in the development of meningioma following head injury. We report a case of primary post-traumatic intraorbital meningioma and discuss its pathogenesis and management.

Intracytoplasmic granulofilamentous inclusion bodies in a meningioma. Immunohistochemical and ultrastructural studies

A case of cerebellar tentorial meningioma, with abundant, large, eosinophilic intracytoplasmic inclusions, was studied immunohistochemically and ultrastructurally. These intracellular inclusions were periodic acid-Schiff negative and ultrastructurally appeared as a condensation or aggregation of numerous intracytoplasmic intermediate filaments. These inclusions were not related to microvillus-lined ductules, indicating that these inclusions were distinct from pseudopsammoma bodies. In addition, these inclusions were intensely immunopositive for vimentin, whereas staining for glial fibrillary acidic protein, epithelial membrane antigen, cytokeratin, neurofilament, desmin, actin, or type IV collagen was negative. To our knowledge, this is the second reported case of meningioma with such unusual inclusions, but the first one to demonstrate that the intracytoplasmic intermediate filaments and their related inclusions were mainly composed of vimentin.

Microcystic meningioma: clinicopathological features of 6 cases

The clinical and morphological features of 6 patients with unusual meningiomas with extensive microcystic formation are presented. There were 4 males and 2 females, ranging in age from 30 to 64 years. The clinical and neuro-imaging features of these tumours were identical with those of meningiomas in general. Morphological examinations disclosed that the tumour cells in 4 cases had many ultrastructural characteristics in common with the arachnoid cap cells, viz. prominent and complex interdigitation of the fine cytoplasmic processes, many desmosomes, and intracytoplasmic microfilaments. In contrast, the tumour cells of 2 cases had characteristic structures in common with trabecular arachnoid cells, viz. stellate in shape, a small number of intracytoplasmic filaments, relatively thick cytoplasmic processes, and occasional desmosomes. The tumour cells in these 2 cases were considered to recapitulate the subarachnoid structure and showed microcystic appearance. Although the histogenesis of microcysts in meningiomas is considered not to be uniform, the biological behaviour of these 6 tumours corresponded to those of meningiomas in general.

Meningioma associated with intratumoral abscess formation--case report

A rare case of meningioma associated with intratumoral abscess formation occurred in a 64-year-old female presenting with septic meningitis and a right frontal mass lesion after a gynecological operation under spinal anesthesia. The mass lesion was totally removed and revealed as an incidental meningioma with an intratumoral abscess. Hematogenous infection of Bacteroides oralis was thought to be the cause of the intratumoral abscess formation.

The use of digital cell image analysis of Feulgen-stained nuclei to quantitatively describe morphonuclear features in a series of 174 meningiomas

The morphonuclear characteristics of 174 meningiomas were quantitatively described by means of the digital cell image analyses of Feulgen-stained nuclei. For this purpose, archival material, i.e., formalin-fixed paraffin-embedded pronase-digested tumors, was used. The present work specifically focuses on the morphonuclear features of angioblastic meningiomas to localize them with respect to classical as opposed to malignant meningiomas. The results show that angioblastic meningiomas, i.e., hemangioblastomas, have morphonuclear characteristics that are very similar to those of classical meningiomas, i.e., meningotheliomatous, fibroblastic, transitional, angiomatous, and psammomatous types, and that are significantly distinct from those of malignant meningiomas. Malignant meningiomas, i.e., the hemangiopericytic and histologic features of malignancy types, are not only significantly different from classical meningiomas in their morphonuclear characteristics but are also very different among themselves. In conclusion, the quantitative description of chromatin features by means of digital cell image analyses confirms at the morphonuclear level the adherence of hemangioblastomas to the group of classical meningiomas, as suggested by the World Health Organization's histopathologic classification.

The significance of nucleolar organizer region (AgNOR) score in predicting meningioma recurrence

BACKGROUND

Argyrophilic nucleolar organizer region (AgNOR) has been demonstrated in recent studies of human brain tumors, including meningiomas. The authors used this technique in meningiomas to analyze whether the mean numbers of AgNOR per nucleus (AgNOR score) are related to the recurrence rate or the proliferative potential of meningiomas.

METHODS

AgNOR staining technique was applied to paraffin-embedded sections of 60 meningiomas. Twenty of these specimens also were investigated immunohistochemically with monoclonal antibody (MoAb) against DNA polymerase alpha (Pol.alpha) and with MoAb Ki-67 to compare the AgNOR score with the proliferative potential.

RESULTS

There was a statistically significant difference between the AgNOR score in nonrecurrent meningiomas (2.48 +/- 0.73) and recurrent histologically benign meningiomas after gross total resection (3.20 +/- 0.96) (P < 0.02). The recurrence rate of tumors after gross total resection with an AgNOR score of 3.0 or more was significantly higher than that with an AgNOR score of less than 3.0. The AgNOR score did not always correlate with Pol.alpha or Ki-67 score; the AgNOR score of malignant meningioma that had high proliferative score was not always high.

CONCLUSIONS

This study indicates that AgNOR staining appears to be a simple and useful method for estimating the probability of histologically benign meningioma recurrence even after gross total resection.

Astrocytes in brain tumours. Differentiation or trapping?

Adult astrocytes have been described in several types of gliomas, being accepted as high differentiated cells. Their presence is specially important concerning the concept of undifferentiated neuroectodermal tumours (PNET). We have studied two series of brain tumors and compared and contrasted them with silver impregnation (89 cases) and GFAP (127 cases). These are our conclusions: these astrocytes show the same morphology not only in neuroectodermal tumours, but also in CNS parenchyma around meningiomas, metastasis and brain lymphomas; many of these astrocytes are mature, normal cells with involutive features, lying among tumoral cells without transitional stages; their presence is directly related to a prominent peritumoral gliosis, a high proliferation rate and an infiltrating growth. On this basis, it is suggested that most of them are astrocytes belonging to the invaded CNS tissue and not true tumoral cells.

[Recurrent meningioma with malignant transformation: a case which changed from meningothelial type to papillary type]

We report here a case with meningioma showing malignant transformation in its course of multiple recurrences. A 59-year-old woman developed a right-sided hemiparesis in June, 1982 and CT scan disclosed a parasagittal well-enhanced mass. The tumor was subtotally removed (Simpson grade III) by an operation in September, 1982. Histological findings of the tumor were consistent with a meningothelial meningioma but showed no malignant features, such as high cellularity, necrotic foci, high mitotic rate, or nuclear pleomorphism. However, the tumor did invade the underlying cerebral cortex. In August, 1986, a recurrent tumor was detected by CT scan and was removed (Simpson grade III). The tumor tissue at the second operation showed the same histological features as the first specimen. In September, 1990, the patient developed multiple intracranial recurrences. There were three tumor nodules, all of which were removed. Histologically, significant histological differences between the second and the third operative specimens were found. In the last tumor tissue, one nodule showed a papillary pattern. In the other tumor nodules, each tumor cell had proliferated separately instead of adhering to other tumor cells to form a syncytium. This histological pattern was consistent with an epithelial meningioma described by Cushing and Eisenhardt in 1938. The papillary portion of the tumor was stained with monoclonal antibody Ki-67 in frozen section. The labelling index was 9.7%, which was as high as malignant meningioma. Electron microscopic examination of the papillary portion of the tumor showed that the tumor cells had irregular nuclei, interdigitations between the adjacent plasma membranes and a few ill-developed desmosomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Meningioma associated with chronic subdural hematoma and meningothelial cell cluster within the hematoma capsule--case report

A 47-year-old female presented with an unusual association of convexity meningioma with chronic subdural hematoma, manifesting as headache and left hemiparesis 10 days before admission. Computed tomography showed an isodense right frontal tumor with significant enhancement postcontrast and a hypodense subdural hematoma in the right frontotemporal area. Craniotomy exposed an extracerebral tumor facing a liquefied subdural hematoma encapsulated by outer and inner membranes. The hematoma was evacuated and the tumor was totally removed. Histological examination revealed a meningothelial meningioma with hemangiopericytic components. Microscopic examination of the hematoma capsule revealed a cluster of meningothelial cells in the outer membrane.

Meningioma with chordoid features

Meningioma is a relatively common intracranial tumor, occurring most frequently in adults, and is capable of a wide variety of growth patterns. We describe a meningioma in a child that had a peculiar chordomalike appearance. The pathologic findings and distinction from chordoma are discussed.

Malignant meningioma of the scalp

A nodule from the scalp of a 14-year-old boy was diagnosed by light and electron microscopy as a meningioma. There was no evidence of an intracranial lesion or involvement of the bone of the skull. The tumor was excised but recurred and metastasized to lung and chest wall.

Novel eosinophilic intracytoplasmic inclusions in a meningioma

BACKGROUND

Two forms of inclusion, extracellular and intracytoplasmic, have been reported in meningiomas. The authors recently encountered a case of meningothelial meningioma with unusual round eosinophilic intracytoplasmic inclusions.

METHODS

Ultrastructural and immunohistochemical studies were performed on the surgically removed tissue.

RESULTS

Ultrastructurally, the inclusions were found in the cytoplasm and processes of the tumor cells. Each inclusion consisted of a dense central mass of filaments with a looser, less dense periphery of radiating filaments. At the periphery, crystalloid lamellar structures and granules were intermingled frequently. No limiting membrane was observed. Immunohistochemically, the inclusions were unreactive for five classes of intermediate filaments, actin, ubiquitin, and amyloid.

CONCLUSION

The intracytoplasmic inclusions were ultrastructurally distinct from those reported previously. The molecular aspect of these novel eosinophilic intracytoplasmic inclusions remained uncertain.

Metastatic meningioma. Hemangiopericytoma or angioblastic meningioma?

The question of whether meningeal hemangiopericytoma is a variant of meningioma ("angioblastic meningioma") or a nosologically distinct entity remains controversial. We present the case histories of an intracranial meningioma and of a meningeal hemangiopericytoma, both of which developed extracranial metastases. The metastatic lesions in both cases were studied by electron microscopy, which demonstrated pericytomatous differentiation in one instance and meningothelial differentiation in the other. This report supports the opinion that meningeal hemangiopericytomas and meningiomas of the CNS are distinct pathological entities.

Cytology of atypical and malignant meningiomas in intraoperative crush preparations

Six cases of atypical and malignant meningioma studied by intraoperative crush preparations are reported. Four atypical meningiomas were characterized by large cohesive and dyshesive cell clusters showing slightly pleomorphic nuclei and scant cytoplasm. The papillary meningioma yielded dyshesive groups of pleomorphic cells with variable and well-defined cytoplasm. The malignant meningioma, hemangiopericytic type, showed dyshesive cells with scant, ill-defined cytoplasm and spindle-shaped or vesicular nuclei.

Meningioma-like tumor of the skin. An ultrastructural and immunohistochemical study

Three unusual cutaneous tumors are described along with ultrastructural and immunohistochemical studies. All lesions were asymptomatic red-brown papulonodules. Light microscopic examination revealed a whorled configuration of spindle-shaped cells, some concentrically arranged around blood vessels. Immunohistochemical panels exhibited positive staining only with antibody to vimentin and negative staining with antibodies against S-100 protein, muscle markers, cytokeratin, epithelial membrane antigen, Leu 7, type IV collagen, and factor XIIIa, ruling out obvious nevomelanocytic, nerve sheath, meningothelial, smooth muscle, and perithelial differentiation. Electron microscopic examination demonstrated cells producing poorly formed collagen fibrils, sparse collagen fibers, and possessing occasional ill-defined intercellular junctions between their elongated cell processes. This rare tumor is considered to be either an immature fibrohistiocytic or possibly a nerve sheath neoplasm with striking similarities to so-called canine hemangiopericytoma. Because the prominent whorled pattern was reminiscent of meningioma, the lesion was referred to as meningioma-like tumor of the skin.

Histological examination of the gadolinium-enhanced dura mater around meningiomas on magnetic resonance imaging

Magnetic resonance imaging often demonstrates gadolinium (Gd) enhancement of the dura mater around meningiomas. The Gd-enhanced dura mater was histologically investigated to detect meningioma cells. Gd enhancement of the dura mater occurred in 11 (79%) of the 14 meningiomas studied, and extended as far as 35 mm from the tumor. Histological examination revealed generation of vascular-rich loose connective tissue at the surface of the dura in all five tumors examined. Some clusters of meningothelial cells were distributed in the loose connective tissue in three of the five specimens, and one cluster was obviously neoplastic. These observations suggest that clusters of meningioma cells occur in the Gd-enhanced dura mater around meningiomas.

Extracranial meningioma in the parapharyngeal space

A case of extracranial meningioma in the parapharyngeal space is reported. A 24 year old woman presented with swelling and tenderness of the parapharyngeal region. A tumor was palpable in this region, and the tumor was surgically removed. Macroscopically the tumor occurred from the portion between the axis and atlas. Histologically the tumor cells, which had oval nuclei and a slightly eosinophilic cytoplasm, proliferated in fibrous connective tissues to form small nests. As the cell borders were not clear, the tumor structure appeared to be syncytium-like. Immunohistochemically the tumor cells were positive for anti-vimentin antibodies, anti-S-100 protein antibodies and anti-epithelial membrane antigen (EMA) antibodies in part. Electron microscopically the tumor cells had complex interdigitations of their adjacent plasma membranes. These were studded with many desmosomes. Bundles of intermediate filaments were visible in the cytoplasm. On the basis of the clinical, histological, immunohistochemical and electron microscopical features, the tumor was diagnosed as extracranial meningotheliomatous meningioma. The parapharyngeal space is an extremely rare location for extracranial meningioma, and our case is the first in Japan as far as we know.

Interaction of magnesium and calcium in meningioma

Ca and Mg contents were determined in 57 meningiomas. Techniques included atomic absorption spectrometry, topochemical detection and electron probe analysis. Elastic fibres demonstrated positive reaction with reagents for detection of Mg. One third of the tumours showed Mg levels higher than Ca levels. The findings gave rise to discussion on the importance of competition and antagonism between Ca and Mg for the formation of calcified structures. As the collagen producing propensity of meningiomas is mediated by interaction with Mg, we speculate that, in addition to the amount of Mg required for basic cell functions, increased Mg levels are needed, especially in the fibromatous variant.

Nucleolar organizer regions in meningiomas

Paraffin sections of 305 meningeal tumours were analysed for the presence of nucleolar organizer region (Ag-NOR) in the neoplastic cells, using a one step silver-colloidal staining method. The mean (+/- SEM) Ag-NOR counts were 2.73 +/- 0.21 for atypical and 2.91 +/- 0.18 for papillary variants of meningioma. In meningotheliomatous and transitional variants of meningioma, the mean Ag-NOR counts were 1.41 +/- 0.34 and 1.38 +/- 0.31, respectively. The recurrence rates were significantly higher in atypical meningiomas than in other histopathological variants (p < 0.05). Differences in the mean Ag-NOR numbers between meningothelial and transitional variants in their primary and recurrent tumours were not significantly different (p > 0.05). The results of this study indicates that estimation of Ag-NORs can be applied in predicting the aggressive clinical behaviour of primary meningeal tumours.

[Meningiomas: morphologic and ultrastructural characteristics of psammoma bodies]

In this study we analyzed the morphologic and ultrastructural characteristics of the psammoma bodies in ten meningiomas of different histologic subtypes, characterizing the components of the psammoma body and the elements of the tumor, such as the capillaries and degenerative cells that have been classically considered as initiators of the formation of these calcareous is structures. The discussion considers the diagnostic interest of psammoma bodies in central nervous system tumors, as well as its histogenesis. The different points of view explaining biological mineralization in other territories of the organism are analyzed, as well as the formation of psammoma bodies, comparing the morphologic data obtained in this study. It is concluded that the mineralization of the psammoma bodies is induced principally by the collagen fibers synthesized by the meningocytes and that the form of mineralization is spherical and growth is radial, controlled by the tumoral cells.