The authors report unusual three cases of large, peri- or intratumoral cystic lesions associated with intracranial meningiomas. These meningiomas may lead to an incorrect presumptive diagnosis because of minic appearance of a glial or metastatic tumor in computed tomography(CT) or magnetic resornance imaging(MRI) finding. Radiological evaluation and recognition are important for the surgical removal of these potentially curable neoplasms.
Diagnosis ; Meningioma*

Intraosseous meningioma of the skull is a rare benign tumor. A case of calvarial origin examined with computed tomography and bone scintigram is reported. The tumor was located in the left fronto-temporo-parietal region, involving the superior orbital fissure. Total removal of the tumor was performed and histological diagnosis of intraosseous meningioma was obtained. Radiological findings and possible histogenetic mechanism of the intraosseous meningioma are discussed.
Diagnosis ; Meningioma* ; Orbit ; Skull

Masson's hemangioma is a rare benign vascualr condition with a papillary intravascular endothelial proliferation which may appear either as aprimary form or as a secondary form in a pre-existing vascular process.CT and angiographic features of 2 cases with Masson's hemangioma were presented. Both of them were locatedextra-axially in the posterior fossa. CT findings were not specific in both cases: One showed homogeneously enhancing mass, simulating meningioma. And the other demonstrated a multiolocular rim enhancing mass. However, the angiographic features were rather characteristic; Both cases showed persistent vascular poolings of contrast mediawhich were supplied form the meningeal vessels. Angiographic differential diagnosis of similar lesions in theposterior fossa is discussed.
Diagnosis, Differential ; Hemangioma ; Meningioma

Microcystic meningioma, a distinct morphological variant of meningiomas, is histologically characterized by a vacuolated appearance with multiple cystic spaces lined by vacuolated or stellate-shaped tumor cells. We report a case of microcystic meningioma occuring in right frontoparietal area of 42-year-old woman, with emphasis on differential diagnosis, along with a review of literatures. Immunohistochemically, most of the tumor cells demonstrated positive immunoreactivity for both epithelial membrane antigen and vimentin. Electron microscopy showed that the extracellular space was extensive, where eletron-lucent material was occasionally seen. The tumor cells had long cytoplasmic processes showing complex interdigitation and a large number of desmosomes.
Female ; Humans ; Diagnosis, Differential ; Meningioma

There is no definite histological criteria which can predict the biologic behavior of meningiomas, although resectability is the most important factor in terms of recurrence. For grading meningiomas, various factors have been studied, such as hypercellularity, nuclear pleomorphism, small cells with high N/C ratio, prominent nucleoli (PN), frequent mitosis, loss of architecture, focal necrosis (FN). We investigated 116 meningiomas to evaluate the correlation between the factors and the proliferative activity using AgNORs and MIB-1 labelling index (LI). They were divided into 3 groups: Group A includes meningiomas with none of the factors; group B with one of the factors; group C with two or more factors. MIB-1 LI was correlated with each factor, but AgNORs was not. There was a statistical difference among group A (<1.28%), B (2.7%) and C (5.1%) (p<0.05) using MIB-1 LI. FN was the most frequently associated with other factors, and it had the highest MIB-1 LI (6.31%). MIB-1 LI of group B was 5.1 2.3%. In group B, the most frequent combination was FN and PN, and it showed the highest MIB-1 LI (5.74%). This study indicates that FN and PN are important for diagnosis of atypical meningioma, and MIB-1 LI appears to be a useful method for estimating the proliferative activity of meningiomas, and 5% or more of MIB-1 LI could help in making a diagnosis of atypical meningioma.
Diagnosis ; Meningioma* ; Mitosis ; Necrosis ; Recurrence

63 patients (male: 45, ages of 9-72) with the superior longitudinal paravenous sinus meningioma operated for removal of tumor and received the postoperative CT scanner and pathological anatomy for checking. Patients with meningioma, which invaded into the lumen of venous sinus but did not obstruct the vein, operated to nearly remove the tumor and excluded the invaded tumor into the venous lumen. Patients with meningioma that invaded into and obstructed the venous lumen received the second operation for legation of sinus and complete removal of the meningioma and obstructed venous sinus. These methods can exclude the disease for a long-time
Meningioma ; Brain Neoplasms ; diagnosis ; surgery

Ectopic meningioma is a rare disease. Three cases of ectopic meningioma, which were located in the diploic space of cranial vaults and orbital roof, is reported. Intradiploic meningiomas may be considered a subgroup of the intraosseous mininiomas. Nomencolature and histrogenesis of this type of meningioma are discussed. And also pathological features and diagnosis are discussed in an attemp to idenify characteristics of these ectopic meningiomas.
Diagnosis ; Meningioma* ; Orbit ; Rare Diseases

Ectopic meningioma is a rare disease. Three cases of ectopic meningioma, which were located in the diploic space of cranial vaults and orbital roof, is reported. Intradiploic meningiomas may be considered a subgroup of the intraosseous mininiomas. Nomencolature and histrogenesis of this type of meningioma are discussed. And also pathological features and diagnosis are discussed in an attemp to idenify characteristics of these ectopic meningiomas.
Diagnosis ; Meningioma* ; Orbit ; Rare Diseases

Approximately 1% of all the meningiomas arise from the extradural space. Intradiploic meningiomas constitutes only a very small percentage of this figure. Because of its rarity, it is often confused preoperatively with primary bone tumors of the skull. The intradiploic meningioma of the orbital wall may be considered as a subgroup of intradiploic ectopic meningioma. The following is our report of a recently observed case of intradiploic meningioma of the orbital wall without intracranial or intraorbital involvement. The preoperative tentative diagnosis was osteoma of the orbital wall. Nomenclature and histogenesis of this type of meningioma are discussed.
Diagnosis ; Meningioma* ; Orbit* ; Osteoma* ; Skull

Approximately 1% of all the meningiomas arise from the extradural space. Intradiploic meningiomas constitutes only a very small percentage of this figure. Because of its rarity, it is often confused preoperatively with primary bone tumors of the skull. The intradiploic meningioma of the orbital wall may be considered as a subgroup of intradiploic ectopic meningioma. The following is our report of a recently observed case of intradiploic meningioma of the orbital wall without intracranial or intraorbital involvement. The preoperative tentative diagnosis was osteoma of the orbital wall. Nomenclature and histogenesis of this type of meningioma are discussed.
Diagnosis ; Meningioma* ; Orbit* ; Osteoma* ; Skull