Meningeal Tumours: a Review

No woman alone: Dorothy Russell's legacy to neurosurgery

Dorothy Russell's contributions to neuropathology are pivotal in the evolution of modern neurosurgery. In an era preferential to men in medicine, she entered the second medical school class to include women at the London Hospital Medical College in 1919. In the laboratory of Hubert Turnbull, she met Hugh Cairns, who would become her professional neurosurgeon-neuropathologist partner. In 1929, arriving at McGill's Royal Victoria Hospital in Montreal, where Wilder Penfield and William Cone had just begun a neurosurgical service, Russell elucidated the origin and activity of microglia. Returning to London, Russell continued to work closely with Cairns for many years. Along with J. O. W. Bland, she became the first to culture gliomas and meningiomas. Her work on the effects of and fatality rates associated with head injuries among soldiers during World War II led to the initiation of helmet requirements for motorcyclists. Her textbook, Pathology of the Tumours of the Nervous System, written with Lucien Rubinstein, is considered a landmark text in neurosurgery, neuropathology, and neurooncology. Honored by Penfield and Cone as their first neurosurgery research fellow, Russell was considered a favorite of the Montreal Neurological Institute. Dorothy Russell's extraordinary career elucidating the mysteries of neurosurgical pathology has made an enduring mark on neurosurgery.

Clinical and Radiologic Characteristics, Surgical Outcomes, and Its Possible Origins of Chondroma of the Dural Convexity

Chondroma of the dural convexity (CDC) is a benign and extremely rare type of intracranial chondroma. In this study, we reported five CDCs in a single center and reviewed the available literature to determine the clinical characteristics and surgical outcomes and possible origins of the disease. The clinical data of five patients (4 females) who confirmed to be CDC between 2000 and 2019 in our single center was collected together with 22 cases from literatures. The clinical characteristics and surgical outcomes were reviewed and analyzed. Among all the available CDC cases, the mean age was 31 ± 13.7 years; the mean tumor volume was 42.3 ± 40.9 cm³, showing a female predominance (63% vs. 37%). The tumors showed calcification in 88.2% cases (15/17) on CT scans and hypointense on T1WI (15/19, 78.9%), mixed intense on T2WI (10/18, 55.6%), and inhomogeneous enhancement without dural tail sign after administration of gadolinium (20/21, 95.2%). Almost all the tumors were misdiagnosed as meningiomas preoperatively. In addition, almost all image available CDC lesions (24/25, 96%) located across the cranial sutures indicating that the tumor originated from ectopic chondrocytes from adjacent skull sutures. No tumors recurred after total resection in follow-up. CDCs are characterized with female predominance and may originate from ectopic chondrocytes from adjacent skull sutures. The lesion with inhomogeneous contrast enhancement without dural tail sign and avascular in cerebral angiography are key points to be differentiated from meningioma. The most effective treatment is total resection.

Chondroma of the falx cerebri: A case report and review of literature

Chondroma is a benign cartilage-forming tumor which usually occurs in small bones of extremities but occasionally occurs in the brain. Usually, intracranial chondromas originate from skull base; however, chondroma of the falx cerebri is a very rare condition. We here report a rare case of falcine chondroma in a 19-year-old man who had normal physical examination without signs of any syndromic disorder. The neuroimaging findings were inconclusive, and the diagnosis was based on histopathological examination. The purpose of this paper is to raise attention about intracranial chondromas and suggest that chondroma must be ruled out in any patient presenting with masses arising from the falx.

A case report on cystic meningioma in cerebellopontine angle and recommendations for management

RATIONALE

Cystic meningioma located at the cerebellopontine angle (CPA) is an extremely rare occurrence. It is frequently misdiagnosed preoperatively. Little is known about the clinical features and outcome of this rare disease.

PATIENT CONCERNS

A 70-year-old male presenting with progressive headache and gait disturbance.

DIAGNOSIS

According to the symptoms, signs, and Gd-enhanced magnetic resonance images (MRI), a preoperative diagnosis of hemangioblastoma located in left CPA was made. Finally, the histological examination revealed a meningioma.

INTERVENTIONS

A complete resection, including the part of the solid mass together with cyst, was performed.

OUTCOMES

The postoperative course of the patient was uneventful, and no residual or recurrent tumor was found during the 24-month follow-up period.

LESSONS

Cystic meningioma should be included in the differential diagnosis of a CPA mass with atypical radiologic features, such as a large cyst and enhanced mural nodule. By summarizing the related literature, we found that the most common pathological subtype of CPA cystic meningioma is the clear cell subtype, which belongs to WHO grade II. Gross total resection including the enhanced cyst wall is extremely important. A close follow-up is necessary because of the high recurrence rate in this subset of meningioma.

Distinguishing Falcine Chondrosarcomas from Their Mimics and Management

BACKGROUND

Primary intracranial chondrosarcoma is an extremely rare malignant tumor of the central nervous system, which accounts for <0.16% of all primary intracranial tumors. This rare tumor has a high associated morbidity from the tumor itself as well as from treatment modalities.

CASE DESCRIPTION

A 33-year-old man presented with a diffuse headache of 3 months' duration. He was admitted to our department with weakness in the right extremities that had persisted for more than a month. Findings of the neurologic examination revealed right hemiparesis. Cranial magnetic resonance imaging demonstrated a well-demarcated, parasagittal left frontal mass, which compressed to the lateral ventricle. It was hypointense on T1-weighted and hyperintense on T2-weighted images without creating edema in the surrounding tissue. A left frontoparietal craniotomy with complete excision of the mass was performed. The postoperative period was uneventful, and patient was discharged on the fourth postoperative day without any neurologic deficit. Histopathology showed a morphology that was in favor of chondrosarcoma grade 1.

CONCLUSIONS

Dural chondrosarcoma is a possible entity in the differential diagnosis of a presumed meningioma, particularly when atypical features are present. We report a grade 1 intracranial chondrosarcoma of the classical subtype without any neurologic problems after complete surgical excision. The patient did not receive any adjuvant therapy and at 26 months' follow-up showed no recurrence.

Intracranial dural chondroma in a child-conventional and advanced neuroimaging characteristics and differential diagnosis

Intracranial chondromas are rare tumors, especially in the pediatric population. We describe the conventional and advanced neuroimaging characteristics of this rare convexity dura-based chondroma in a young adolescent. In particular we demonstrate that diffusion-weighted imaging (DWI) facilitates differentiation between a dura-based chondroma and the more frequent classical meningioma. Chondromas are typically DWI hypointense with high apparent diffusion coefficient (ADC) values while meningiomas are typically DWI hyperintense with low ADC values. We also discuss the relevant additional differential diagnoses of dura based focal lesions for the pediatric population as well as the diagnostic significance of additional imaging modalities, including computed tomography, magnetic resonance imaging and cerebral angiography.

Intradural chondroma in the cervical spine: case report

Chondromas are benign tumors that are rarely located in the spine. The authors present a rare occurrence of a spinal chondroma that developed as an intradural but extramedullary tumor in a 60-year-old woman. The location of the tumor at C4-5 was confirmed by MRI, with hyperintensity on T2-weighted images and isointensity on T1-weighted images. The tumor was completely contained intradurally, with no continuity to any vertebrae. It adhered to the anterior dura, indicative of its likely origin from the dura mater. The tumor was completely resected, with no sign of recurrence after 3 years postoperatively. Although reports of chondromas originating from the dura mater have been previously described, these have all been intracranial tumors. To the best of the authors' knowledge, this is the first report of an intradural chondroma located in the spine. Therefore, chondromas should be considered in the differential diagnosis of intradural spinal tumors.

Intracranial dural based chondroma

Intracranial chondromas are benign, slow-growing, cartilaginous tumors, which comprise only about 0.2% of all intracranial tumors. The majority of these lesions occur at the base of the skull, where they are thought to arise from residual embryonic chondrogenic cells along the basal synchondrosis. Very rarely, they may also originate from the convexity dura, falx cerebri, or the brain parenchyma. We present a patient with a dural based chondroma to highlight the technical considerations of surgical resection. The recent literature on intracranial chondromas regarding incidence, pathophysiologic origin, clinical symptoms, imaging, histopathology and prognosis is reviewed.

Intracranial parafalcine chondroma in a pregnant patient

Background:

Intracranial chondromas are rare benign neoplasms. We report a patient incidentally diagnosed with an intracranial chondroma during her second trimester.

Case Description:

A 22-year-old Caucasian was diagnosed with an incidental parafalcine lesion found during admission due to a motor vehicle accident. Prior to the admission, the patient did not present with any neurological symptom. Magnetic resonance spectroscopy (MRS) suggested this intracranial lesion to be benign. A decision was made to delay the tumor excision until after delivery. Special anesthesia considerations were made to maintain stable blood pressure and euvolemia during the Cesarean section. The patient underwent a successful gross total removal of the intracranial tumor two months postpartum without any post-operative deficit.

Conclusion:

This is the first case report of an intracranial parafalcine chondroma in pregnancy. This report highlights the disease course of this rare type of tumor during pregnancy. This case illustrates relevant aspects of the management of a neurologically asymptomatic patient with an incidentally discovered intracranial tumor of which MRS suggested a benign nature.

Chondroma of the dural convexity: a case report and literature review

Chondromas are unusual tumors that arise from the base of the skull and have a predilection for the spheno-ethmoidal region. Chondromas represent less than 0.5% of all intracranial tumors. In rare instances, these tumors originate from the dura mater of the convexity. Fewer than 30 cases of dural chondromas arising from the convexity or the falx are reported in the literature. In this study, we describe a new case of convexity chondroma. We discuss the radiological and histological features of this case and also review the literature.

Intracranial falcine and convexity chondromas: two case reports

Intracranial chondromas are uncommon intracranial tumours that most frequently arise from the skull base. They can, however, arise from the calvarium or the meninges. In these cases their neuroradiological features may mimic other intracranial tumours. We present two cases of intracranial chondroma, one that originated from the convexity and the other from the falx. Total excision was achieved in both cases. The literature on intracranial chondromas is reviewed.

Primary falcine chondrosarcoma

Non-skull-base intracranial chondrosarcomas are extremely rare. We present a patient with a classic falcine chondrosarcoma and review the radiological features that may aid in a pre-operative diagnosis, as well as the adjuvant treatment options. A 32-year-old woman presented with a 5-year history of progressive weakness in her right leg. MRI scan demonstrated a 4.9 x 4.3 x 2.7 cm irregular parasaggital mass in the left frontoparietal region that was in contact with the falx. A left fronto-parietal craniotomy was performed and gross total excision was achieved. Intracranial chondrosarcomas that occur above the skull base tend to be of the mesenchymal variety. Classic chondrosarcomas of the falx are rare. The management of these tumours is surgery, with adjuvant radiotherapy for incompletely excised lesions.

Intracranial falx chondroma: Literature review and a case report

Intracranial chondromas are benign tumors that represent approximately 0.5% of all intracranial tumors. They usually occur at the base of the skull but on rare occasions might present as intra-parenchymal or intra-ventricular space-occupying lesions, most likely originating from heterotopic chondrocytes or metaplastic fibroblasts of the falx, the convexity dura, or the ventricular ependyma. Chondromas are slow-growing tumors, which remain clinically silent for a prolonged period of time in the majority of cases. Their clinical presentation is non-specific and their radiographic appearance usually does not differentiate them from their more common counterparts, such as meningiomas and glial tumors. As a result, their diagnosis has remained a histopathologic one. In our current study, we present a case of a falcine intracranial chondroma. This case provided the opportunity to extensively review the pertinent literature.

[Cranial vault chondroma: a case report and literature review]

Intracranial chondromas are unusual tumors, which most commonly arise from cartilage rets in the synchondrosis at the base of the skull. They are most likely found in the sellar and parasellar regions, usually located extradurally. In rare instances, these tumors originate from the dura mater of the convexity. In these cases their neuroradiological features may mimic other intracranial tumors. We present the case of a 50-year-old male presenting a large parasagittal tumor originating in the frontal convexity. MRI-scans revealed a cavitated tumor strongly enhanced after gadolinium infusion mimicking a parasagittal meningioma. There was no obstruction of the superior sagittal sinus as shown by cerebral angiogram. Total excision was achieved and the postoperative course was uneventful. No complementary treatment was therefore considered. The histological examination diagnosis was chondroma. Radiological workup performed at four years follow-up did not reveal any recurrence of the lesion. Pathogenic, clinico-radiological and therapeutic issues are discussed and the literature reviewed.

Anaplastic ependymoma with cartilaginous and osseous metaplasia: report of a rare case and review of literature

Gliomas with cartilaginous metaplasia are extremely uncommon and thought to be due to metaplasia of the mesenchymal supportive elements. The tumors are located in the midline, mostly fourth ventricle and rarely in the pons. The present paper describes an unusual case of anaplastic ependymoma with cartilaginous and osseous metaplasia in a young boy which was located in the suprasellar, interpeduncular prepontine and left cerebello-pontine cistern. To the best of our knowledge, this cartilaginous metaplasia in ependymomas has been reported only thrice.

Intracranial chondrosarcoma: a case report and review of the literature

OBJECTIVE AND IMPORTANCE

Chondrosarcomas rarely occur intracranially away from the skull base. We present a case of a supratentorial dural-based, low-grade classic chondrosarcoma and emphasize salient imaging findings that assist in its diagnosis.

CLINICAL PRESENTATION

A 23-year-old female presented with new onset seizures. Multiple radiographic imaging studies identified a large left frontal mass with radiological findings that suggested the correct diagnosis.

INTERVENTION

The patient underwent a left frontal craniotomy and gross total resection of the lesion and associated dura.

CONCLUSION

Intracranial chondrosarcomas away from the skull based are extremely rare malignancies. As with other extra-axial masses, they often grow to a relatively large size before generating symptoms. Careful analysis of CT, MR, and angiographic imaging characteristics should suggest the correct diagnosis.

Giant chondroma arising from the dura mater of the convexity. Case report and review of the literature

Chondromas arising from the dura mater are rare intracranial tumors. The authors present a case of intracranial giant chondroma originating from the dura mater of the convexity. Neuroimaging and surgical findings are described. The diagnostic clues are discussed and similar cases from the literature are reviewed.

Primary intradural classic chondrosarcoma: case report and literature review

OBJECTIVE AND IMPORTANCE

The exact origin of rare intradural chondrosarcomas remains obscure. We present a case report of an intradural classic chondrosarcoma (a very rare subtype of chondrosarcoma in this location), with a review of the literature, in an attempt to clarify the histogenesis of these tumors.

CLINICAL PRESENTATION

A 48-year-old man presented with a 12-month history of progressive right hemiparesis. Computed tomography and magnetic resonance imaging demonstrated a left parietal space-occupying lesion.

INTERVENTION

The patient underwent an image-guided, left parietal parasagittal craniotomy. An extrinsic tumor, which seemed to arise from the dura, was macroscopically removed. There was no bone involvement. The histological examination revealed a Grade II classic chondrosarcoma with tumor infiltration into the dura. Adjuvant radiotherapy was administered.

CONCLUSION

Intradural chondrosarcomas are rare tumors, the majority of which are mesenchymal. Classic chondrosarcomas in this location are much rarer. Their histogenesis is uncertain. In this case, the origin seems to be from the dura. Because of the malignant potential of these tumors, radical extirpation whenever possible, followed by radiotherapy, is indicated.

Giant chondroma of the falx. Case report and review of the literature

The authors describe the radiological and pathological features in a patient with an intracranial chondroma originating in the falx cerebri. Diagnostic procedures and management in treatment are discussed, and a review of the literature is presented.

Intracranial chondroma. Report of two cases and review of the literature

INTRODUCTION

Chondromas are rare intracranial tumors. The authors present two cases of intracranial intradural chondroma, one originating from the falx cerebri and the other from the dura mater of the convexity.

METHOD AND RESULTS

Diagnostic procedures, including magnetic resonance imaging, and surgical findings are described. In both cases, pre-operative diagnosis could have been at least suspected, and the tumor was completely removed, without recurrence after a follow-up of many years. The pathogenesis and pathological findings are discussed, and cases from the literature are reviewed.

CONCLUSION

Benign intradural chondroma has a good prognosis, with no recurrence after surgical excision in most cases.

Spontaneous osteosarcoma of the meninges in an albino rat

A search of the rat tumor literature revealed no papers on naturally occurring primary osteosarcoma of meninges. In humans, this tumor, arising primarily from the meninges, is unusual; only two cases have been reported. We report on a spontaneously occurring osteosarcoma arising from meninges in a 2-year-old female albino rat. The diagnosis was made on the basis of gross, microscopic, and ultrastructural findings. The diagnosis of this neoplasm is supported by the fact that a primitive mesenchymal cell in the meninges is capable of giving rise to a wide variety of neoplasms.

Two distinct intracranial tumors of different cell types in a single patient. Case report and review of the literature

We report the case of a patient with two distinct brain tumors. A meningioma was resected surgically. Nine months later a glioblastoma appeared in the same region, but at a different site. This was not treated, because the patient died. The clinical significance and etiology of these tumors are considered.

Solitary intracranial chondroma of the convexity dura: case report

We present a rare case of chondroma originated from the dura mater of the cerebral convexity in a 16-year-old girl. Radiologic findings are reported with emphasis on computed tomography and magnetic resonance imaging scans, and histogenesis is briefly discussed.

Primary papillary meningioma of the optic nerve sheath: a case of unique location and benign pathology

I report here a case of primary papillary meningioma of the optic nerve sheath which developed in the left eye of a 54-year-old woman over a period of 20 years. A review of 123 primary papillary meningiomas, including the current instance, disclosed that they tended to occur in young patients of both sexes at an average age of 35 years, with one-fourth of them occurring in the first two decades of life, and with a female/male ratio of 3:2. These meningiomas were most frequent in the supratentorial compartment of the cranial cavity, especially on the cerebral convexity and in the parasagittal region. They were uncommon subtentorially, intraspinally, and outside the central nervous system. Most reported papillary meningiomas were claimed to be malignant, but the tumor of this particular woman was benign pathologically and clinically.

Gliofibromas (including malignant forms), and gliosarcomas: a comparative study and review of the literature

The presence of connective tissue elements in gliomas necessitates in every case a thorough analysis of the character and derivation of such elements to allow the formulation of an appropriate diagnosis. Four cases are presented in this paper. In cases 1 and 2 (anaplastic astrocytomas in two children, 9 and 4 years old, respectively) all the neoplastic elements were astrocytes and their ability to produce or indirectly promote the production of reticulin and collagen fibers accounted for the presence of such elements in close association with the tumor cells. The term "gliofibroma" has been coined for such tumors, but "desmoplastic astrocytoma", (low grade or anaplastic) or in highly malignant cases "desmoplastic glioblastoma", as the case may be, also seem to be appropriate terms for such neoplasms. In contrast, cases 3 and 4 represented composite tumors in adults (66 and 58 years old, respectively) and the neoplasms of these patients consisted of glioblastoma and sarcoma, the latter component demonstrably being of vascular origin. This is the type of tumor usually referred to as gliosarcoma or "Feigin tumor". Although some apparent similarities between the two groups may exist at times, the histogenesis of the latter group's sarcomatous or sarcoma-like portions is different from that of the first group and, therefore, warrants separate diagnostic terms and placement in brain tumor classification.

Intracranial meningiomas associated with glial tumours: a review based on 54 selected literature cases from the literature and 3 additional personal cases

The simultaneous occurrence of meningioma and glioma is extremely rare. Three new cases and 54 adequately described in the literature are analyzed. Clinical diagnosis may be difficult due to discrepancy between clinical and radiological findings. Unexpected clinical deterioration following removal of a tumour and relapse simulating recurrence may occur. The introduction of CT technology does not seem to have offered the expected contribution to the early diagnosis of these coincidental lesions, at least before the introduction of the newer generation scanners or MRI. While removal of both tumours in one session yielded the best results, surgery for the sole glioma appeared to be associated with an unacceptably high mortality. Although several aetiopathogenetic hypotheses have been suggested for explaining this curious association, coincidental meningioma and glioma are most likely to be different primary brain tumours occurring randomly in the same individual.

Malignant meningioma with cartilage and giant cells

An autopsy case of recurrent and malignant meningioma is reported. This case was originally typical benign transitional meningioma of the falx, however, the histology of the tumor changed to show malignant features during successive recurrences. At autopsy, the tumor revealed findings consistent with malignant meningioma. One of the most interesting features was the presence of cartilage and giant cells in some parts. Immunohistochemistry showed positive immunoreactivity for S-100 protein in some cartilage and giant cells and for cytokeratin in some giant cells. Multidifferential potential of the meningioma cells was suggested in this case.

Lipomatous meningioma--an uncommon tumor with distinct radiographic findings

A case of lipomatous (lipoblastic) meningioma is described. Atypical radiographic features of low density on computed tomography scanning and high intensity on T1-weighted magnetic resonance imaging corresponded to the presence of adipose tissue within the tumor. A review of the literature indicates few similar reported cases.

Papillary meningioma arising from the confluens sinuum with multidirectional extension through venous sinuses

Successful removal of a meningioma arising from the confluens sinuum is described. This tumor extended multidirectionally through the venous sinuses (superior sagittal sinus, bilateral transverse sinuses, straight sinus, and occipital sinus) and protruded like a club in nodular pattern from the left inner surface of the confluens sinuum into the left occipital lobe. The tumor was completely removed via a bilateral large parieto-occipito-suboccipital craniotomy. Angiographically, unusual venous drainage from the vein of Galen into the superior sagittal sinus was demonstrated. Histologically, this tumor was a papillary meningioma characterized by two types of papillary structure in many areas.

Intracranial chondroma. Case report

We present a rare case of intracranial chondroma originating from the falx cerebri. Diagnostic procedures and surgical management are discussed, with special reference to computed tomography, magnetic resonance imaging, and pathologic findings.

Meningeal chondrosarcomatous tumor associated with meningocytic differentiation

Most meningeal chondrosarcomatous tumors have been regarded as identical to similar tumors occurring elsewhere in the body. The neoplasm reported here, however, clearly demonstrated transitions between usual meningiomas and chondrosarcomatous tumors. The present case thus provides evidence in support of Cushing's and Eisenhardt's proposal that some meningeal chondrosarcomatous tumors are derived from meningeal cells and are histogenetically related to meningiomas.

Capillary hemangioblastoma: histogenesis of stromal cells

The histogenesis of stromal cells in capillary hemangioblastoma has been the subject of debate. The light and electron microscopic studies of hemangioblastomas presented here showed pericytic and leiomyoblastic features in stromal cells. Cells cultured by the monolayer method showed similar features to those of the original tumors. Immunohistochemical studies for glial fibrillary acidic protein and factor VIII/von Willebrand factor indicated that stromal cells were antigenically distinct from astrocytes and endothelial cells. These findings suggest that stromal cells are closely related to pericytes and smooth muscle cells, and support Rhodin's speculation that pericytes serve as a precursor to smooth muscle cells.

Papillary meningioma. Clinicopathologic study of seven cases and review of the literature

Seven cases of papillary meningioma are reported. The patients, 3 females and 4 males, were aged between 21 and 69 years. Five tumors were supratentorial, 1 was located in the left temporal bone, and 1 in the thoracic spinal canal. Five patients had local recurrences and died within 1.4 to 9 years of the original operation. In Case 2, one small pulmonary metastatic nodule was found at autopsy. Microscopically, these meningiomas showed foci of necrosis, numerous mitotic figures and local invasiveness. Psammoma bodies were occasional or absent. Forty-six papillary meningiomas have been identified in the literature. Certain histologic features (necrosis, high mitotic index, rich peripapillary reticulin network) and evolutive events (high rate of local recurrence, development of distant metastases) suggest that this aggressive variant of meningioma could form a histologic link between syncytial, fibroblastic, and hemangiopericytic meningiomas.

Chromosome abnormalities in meningiomas

Cytogenetic analyses of eight meningiomas grown in culture for 1 week are reported. Normal karyotypes were found in three cases and hypodiploidy in the remaining five. In the five hypodiploid meningiomas, one chromosome #22 was missing in four cases, and one case exhibited a 22q- deletion. In four of these five cases, chromosome #14 was either lost or altered. Chromosome #1 was lost or altered in three, and chromosome #6 in two. These findings lend further support for the association of total or partial loss of chromosome #22 in meningiomas and suggest the involvement of other chromosomes in the clonal evolution of these tumors.

Supratentorial haemangioblastoma: the diagnostic roles of computed tomography and angiography

Two patients with von Hippel--Lindau complex are described. Both had concomitant posterior fossa and supratentorial haemangioblastomas. The value of cerebral angiography is stressed in the demonstration of small nodules which are not immediately apparent on the computed tomogram.

Papillary meningioma

Six cases of papillary meningioma are described. Five patients are still alive 2 months, and 2, 7, 8 and 14 years after the operation respectively. No metastases or recurrences have been noted. One patient died from an intercurrent disease 2 years after operation. In all cases the papillary pattern was associated with one of the typical well known forms of meningioma. One case showed histologic features of anaplasia, i.e.: local high cellularity accompanied by mitotic activity and pleiomorphism. Only one or two features suggestive of a higher growth dynamism were noted in the other cases. The mechanism of the papillary structures is discussed. Vasotropism and a feeble cohesion between the cellular perivascular "crowns" are thought to be responsible for the papillary pattern which should be interpreted as a secondary phenomenon. It appears likely that the papillary pattern of meningioma is not always an expression of anaplasia when no other clinical and histologic signs of malignancy are present.

Oligodendrogliomas of the spinal cord

The clinical, surgical, and pathological data from 35 published cases of oligodendroglioma and of one personal case are analysed and compared with those from other tumours of the cord and from cerebral oligodendrogliomas. Oligodendroglioma of the cord has a slightly lower average age than other gliomas and is closer to that of glioblastoma. In oligodendroglioma of the cord, as of the brain, acute onset or aggravation of the symptoms and an oscillating course are frequent. Two correlated data are particularly worth noting: a) the mean CSF protein content in oligodendroglioma of the cord is higher than in any other glioma; b) intracranial hypertension, in the form of papilloedema or hydrocephalus, or both, was present in 31% of cases. This signifies cerebral oligodendrogliomatosis, which was found in 6 out of 10 necropsied cases. At operation most oligodendrogliomas of the cord appear as infiltrating "gelatinous" tumours, though a minority have a firm consistency and apparently clearcut contours, which seem to be associated with a better prognosis. Postoperative radiotherapy seems to be useful.

Simultaneous occurrence of right supratentorial meningioma and glioblastoma multiforme. Case report

We report the case of a 63 years old male with two intracranial tumours, a meningioma and a glioblastoma multiforme. We have reviewed the relevant literature, and have speculated on the causes of this phenomenon.

Papillary meningioma: a malignant variant of meningioma

A series of 17 meningiomas histologically characterized by a papillary pattern is reported. This pattern was invariably associated with other histologic features of malignancy. The tumors often displayed aggressive clinical behavior marked by a high rate of local recurrence or the development of distant metastases. A relatively large proportion occurred in children. It is suggested that this variant of meningioma is sufficiently characteristic to justify its separation as a distinct clinicopathologic entity.

The diagnostic problem of multiple intracranial tumours--case report of a pituitary chromophobe adenoma and cerebellar haemangioblastoma

The clinical and pathological details of a case in which a pituitary chromophobe adenoma and a cerebellar haemangioblastoma occurred simultaneously are presented and the diagnostic problems discussed. This is a rare combination considering the disparate tissue origin of the two tumours.

Cerebellar capillary hemangioblastoma: its histogenesis studied by organ culture and electron microscopy

A capillary hemangioblastoma from the vermis of a 21-year-old man with von Hippel-Lindau's disease was successfully maintained in organ culture systems on Millipore filter platforms and gelatin sponge foam matrices up to 48 days. Three cell types--endothelial cells, pericytes, and stromal cells--identified by their fine structural features and their architectural relationships to vascular lumens and to the extracellular space were recognized in the original tumor. By light microscopy the explants showed, in the late stages, increased lipid droplets in the stromal cells and perivascular hyaline thickening. By electron microscopy, endothelial cells, pericytes, and stromal cells remained distinguishable as cell types. However, the stromal cells demonstrated, in addition to an increase of their normal complement of microfilaments and lipid droplets, features that were more characteristic of the two other cell types, i.e. micropinocytotic vesicles and the formation of zonula occludens junctions and hemidesmosomes. Basement membranes also became more apparent around the stromal cells. With increasing time in vitro, there was a striking increase in mature collagen fibers in the extracellular space. The roles of the different cell types in capillary hemangioblastoma and the histogenesis of the stromal cells are discussed in light of these observations. It is concluded that the capillary hemangioblastoma consists of multiple cell lines--endothelial cells, pericytes, stromal cells and, occasionally, hematopoietic cells--all of which are neoplastic and replicate in parallel with one another. Stromal cells may be regarded as an aberrant monopotential cell type which shares with the endothelial cell and pericyte a common mesenchymal, presumably angiogenic, ancestry, and may, on occasion, display morphological features, such as increased basement membrane formation and the formation of zonula occludens junctions, which recall its angiogenic lineage. However, interconvertibility between endothelial cells and stromal cells does not appear to occur in vivo or in vitro.

Malignant meningioma metastasizing through the cerebrospinal pathways

A 53-year old man presented with a malignant meningioma which was incompletely removed. The tumour subsequently metastasized through the cerebrospinal pathways causing clinical signs through invasion of the cranial nerve roots. Microscopically, the metastatic deposits displayed a papillary pattern and increased anaplastic cytological features.

Pathological and haematological aspects of posterior fossa haemangioblastomata

A retrospective study has been carried out on 67 patients harbouring 78 posterior fossa haemangioblastomata. The site, macroscopic nature, and histological features are described, and correlations sought with the degree of erythrocytosis in the peripheral blood. The problems of aetiology are discussed and a single hypothesis advanced.