Cystic changes in intracranial meningiomas. A review

Cystic meningiomas: A complex diagnostic challenge and clinicopathological insights from a unique case presentation

Meningiomas present diverse clinical and radiological characteristics, with cystic formations constituting a lesser subset but posing significant diagnostic hurdles. We explore the complexities of cystic meningiomas through a distinctive case, highlighting the challenges in diagnosis and management due to their variable presentations. A 54-year-old female from Bengaluru, Karnataka, initially presented with transient memory disturbances. Brain MRI revealed a sizable left frontal cystic lesion exerting a mass effect and midline shift. However, rapid neurological decline led to an urgent surgical intervention via decompressive craniectomy unveiling unique intraoperative findings and with subsequent histopathological documentation of a Grade WHO 1 cystic meningioma. Cystic meningiomas present intricate diagnostic challenges resembling other intracranial lesions. Various classification systems attempt to categorize these tumors based on their imaging and histopathological characteristics. Despite this, atypical clinical manifestations often lead to misdiagnoses, necessitating a comprehensive approach to differential diagnosis. Further research is crucial to unravel the mechanisms underlying these tumors' cystic changes for improved diagnostic accuracy and tailored therapeutic interventions.

Dural Cavernous Hemangioma: An Under-recognized Lesion Mimicking Meningioma

We report a 77-year-old woman who presented with partial seizures and was found to have an enhancing dural-based parietal convexity mass. The lesion enlarged on serial examination by computed tomography (CT) over a one year period. The clinical features and radiologic appearance were compatible with a pre-operative diagnosis of meningioma; however, pathologic findings were typical of a dural cavernous hemangioma. Accumulating evidence suggests that these lesions are an uncommon but distinct type of vascular malformation most often arising from the cavernous sinus, tentorium, or cerebello-pontine angle. With CT, magnetic resonance imaging and angiography, these lesions can closely resemble meningioma in terms of signal characteristics, enhancement pattern, and location. This is of importance both in the practical management of meningiomas where the diagnosis is often based on radiologic studies alone, and in clinical trials where incorrect entry diagnosis should be avoided.

Usefulness of 320-row area detector computed tomography for the diagnosis of cystic falx meningioma

We present a case of cystic falx meningioma. Cystic meningioma is rare and not easy to diagnose preoperatively; it is often misdiagnosed as other tumors, including glial or metastatic tumors with cystic or necrotic changes. This study showed the potential impact of 320-row computed tomography (CT) on image-based diagnostic evaluation of cystic meningioma with special attention to the novel techniques of 4-dimensional CT angiography (4D-CTA) and CT whole-brain perfusion (CTP). 4D-CTA showed the arterial supply feeding the tumor and late enhancement of the tumor nodule, similar to that seen in meningioma by conventional angiography. CTP showed that the tumor had a higher cerebral blood flow and cerebral blood volume and a longer mean transit time than adjacent brain tissue. These findings were consistent with meningioma and reinforced the other imaging findings, resulting in the correct preoperative diagnosis. The new techniques available for 320-row CT can potentially be used to improve differential diagnosis and preoperative assessment of cystic tumors with nodules.

Clinical analysis for an unusual large cystic meningioma: case report and review of the literature

The authors report the case of a 17-year-old boy with an unusual large cystic meningioma (Nauta type II) in the right hemisphere. The imaging appearances of this patient were very unusual. The shape of the huge cyst was crescentic and similar to subdural hematoma. It lay between the dura and the solid tumor parts. In addition there was a small intracystic nodule attached to the cyst wall. The patient underwent a right hemisphere craniotomy. At surgery it was found that the cyst contained a large amount of xanthochromic fluid and some semitransparent serumlike sediment. The intracystic nodule was proved to be necrotic substance without tissue and cell structure. Histological examination displayed an anaplastic meningioma, of which the cyst wall also consisted of meningioma tissue. To the best of the authors' knowledge, such an unusual case of cystic meningioma has not been reported. The authors review the literature with reference to intratumoral cyst associated with meningiomas, analyze the unusual imaging appearances of this patient, and explore the mechanism of cyst formation. The mechanism of cyst formation associated with meningiomas is not perfectly understood. Intratumoral cyst formation may be attributed to microcystic degeneration, ischemic necrosis, intratumoral hemorrhage, transudation and secretory changes within the tumor.

[Cystic meningioma. Case report and literature review]

BACKGROUND

Cystic meningioma is a rare variety of meningioma. It represents 1,6 to 10% of intracranial meningiomas, the authors report a case of intracranial cystic meningioma with a review of literature.

CASE REPORT

A 46-year-old female presented with left parietooccipital headache followed by right side hemiparesis. CT scan brain showed a left parietal tumor with double solid and cystic components thought to be glioma or metastasis preoperatively. At surgery the extraaxial solid and cystic lesion had a well defined capsule that could be easily separated from the perilesional cortical surface. The tumor was totally removed. The histological study showed a cystic meningioma.

CONCLUSION

Cystic meningioma is an uncommon tumor that should be considered in the differential diagnosis of brain tumors with a cystic component.

Cystic meninigioma

To study the clinical characteristics of cystic meningiomas, we analyzed retrospectively 21 patients with cystic meningiomas and reviewed the literature with regard to clinical presentation, imaging features, preoperative diagnosis, surgical findings, and histopathological results. The cysts were classified into intratumoral and peritumoral cysts based on their relationship to the tumor, and also according to the classification method described by Nauta. For the 21 patients in our group, there were seven peritumoral cysts and 14 intratumoral cysts. Various pathophysiological mechanisms contribute to the formation of cystic meningiomas. The diagnosis of cystic meningiomas based on CT scan can be problematic, and differentiation from glioma or metastasis may be difficult. MRI scans show low signal intensity areas within the mass on T1-weighted images and high signal intensity areas on T2-weighted images, and the solid parts of tumors are contrast-enhanced after gadolinium administration. MRI with gadolinium enhancement dramatically increases the diagnostic accuracy for cystic meningiomas and provides critical information for their surgical care. Total surgical resection of cystic meningioma is ideal, but special attention should be paid to the cyst walls.

Clinical and histopathological analysis of cystic meningiomas

Between 1993 and 2003, we treated 21 patients with cystic meningioma (of 365 with meningioma, 5.5%). We grouped these patients according to classifications by Nauta and Rengachary and analyzed them by gender, age, tumor location, clinical manifestations, MRI features and histopathology. The mean duration of symptoms was relatively short at 1.6 months. There were five atypical and 16 benign meningiomas on histopathology. In type I and II cystic meningiomas, with intratumoral cysts, all cyst walls enhanced on MRI and had tumor cells in the cyst wall on histopathology. In type III and IV cystic meningiomas, with peritumoral cysts, the cyst wall did not enhance on MRI and only one case (type III) had tumor cells in the cyst wall on histopathology. We suggest that when the cyst wall shows contrast enhancement on imaging, the cyst wall should be completely removed at surgery. If there is no contrast enhancement, multiple biopsies of the cyst wall should be taken to assess the presence of tumor cells in the cyst wall.

Suprasellar cystic meningioma: unusual presentation and review of the literature

We report on a case of suprasellar cystic meningioma. The magnetic resonance imaging of this tumor resembled that of a craniopharyngioma. The definitive diagnosis of meningioma was made only after histopathological confirmation. We conclude that preoperative studies are often equivocal. The possibility of meningioma should be considered in the diagnosis of any intracranial neoplasms with radiological and surgical evidence of a cystic lesion.

Dumbbell-shaped meningioma with cystic degeneration in the thoracic spine: a case report

STUDY DESIGN

A case report of dumbbell-shaped meningioma in the thoracic spine with cystic degeneration for which a combined posterior microscopic and anterior thoracoscopic approach was used is described.

OBJECTIVES

To report a rare case of dumbbell-shaped meningioma, and to describe a thoracoscopic surgical approach for paravertebral tumor.

SUMMARY OF BACKGROUND DATA

Dumbbell-shaped tumors arising from nerve root sheaths are very common. However, a dumbbell-shaped meningioma is relatively rare, and reports on thoracoscopic resection of dumbbell and paravertebral tumors are still very few in number.

METHODS

The dumbbell meningioma was managed surgically. Because of the paravertebral tumor's intrathoracic expansion, a combined posterior and anterior approach was used. With the posterior approach, microscopic resection using hemilaminotomy was performed, whereas with the anterior approach, the thoracoscopic approach was used instead of thoracotomy.

RESULTS

Complete resection of the tumor was performed successfully. The patient regained his functional ability to walk soon after surgery because of less pain than with thoracotomy.

CONCLUSIONS

With combined microscopic and thoracoscopic surgery, dumbbell-shaped meningioma could be completely resected. The thoracoscopic approach for the removal of a paravertebral tumor can be a good alternative to thoracotomy.

Intracerebral cyst associated with meningioma

A 27-year-old male had experienced an episode of severe headache and nausea, sometimes accompanied by an inability to name objects. Magnetic resonance imaging showed a huge cyst within the left temporal lobe and a high degree of brain shift by it. A small round mass, which appeared to be a mural nodule, was located in the tip of left middle fossa. It was highly enhancing together with its attached dura mater, but the cyst wall was not enhanced. Sphenoid ridge meningioma with an associated intracerebral cyst or cystic glioma invading the dura mater was suspected. During surgery the small tumor was found to be arising from the sphenoid ridge and evaginating into the tip of the temporal lobe. The intracerebral cyst had a smooth surface and the tumor was visible outside the cyst through its wall. The tumor was totally removed, but the cyst wall was left without excision. Postoperatively he had no symptoms. Histological examination showed a microcystic meningioma. It is stressed that differentiations of cystic meningiomas from other cystic tumors and, of intratumoral from extratumoral cystic meningiomas using radiological, operative or histological findings are important.

Cystic meningioma: neuroradiological (MRI, CT) and macroscopic intraoperative appearance. A case report

Differential diagnosis of intracranial cystic meningiomas may present difficulties in about 10-15% of cases where anatomo-pathological alterations such as intratumoral necrosis, cystic cavity, hemorrhage or lipomatous infiltration are present. These alterations are responsible for an unusual radiological appearance which may suggest a false diagnosis. We describe a case of meningioma with a cystic appearance in which MRI was more helpful than CT, because it suggested an extra-axial meningiomatous lesion and thus allowed more precise surgical planning.

Cystic meningiomas resembling glial tumors

BACKGROUND

Meningiomas can be associated with peripheral or intratumoral cysts. Meningiomas with intratumoral cysts, also called "true cystic" meningiomas, are rare and can frequently be confused with glial or metastatic tumors.

METHODS

We report three cases of "true cystic" meningiomas and discuss the preoperative evaluation, etiology, and surgical treatment of these cystic lesions with reference to the literature.

RESULTS

Magnetic resonance imaging (MRI) and computed tomography (CT) studies usually display a cystic lesion close to the dura with or without enhancement of the cyst wall. Multiplanar MRI scans are very useful to show the presence of a solid tumor or some dural enhancement. Some cases of "true cystic" meningiomas however, are still erroneously preoperatively diagnosed. Complete surgical removal of the tumors and of the entire cyst wall was performed in our cases. Despite the absence of a typical ring enhancement of the cystic lesion in two cases, histopathologic studies displayed the presence of tumor cells on the cyst wall of both cases.

CONCLUSIONS

Tumor cells can be present on the cyst wall and therefore can be one of the causes of tumor recurrence if not totally removed. Accurate preoperative radiologic diagnosis (multiplanar MR images) and intraoperative histopathologic studies are fundamental in that they will definitely influence the surgical strategy and outcome.

Cystic meningiomas in children: a diagnostic challenge

Two cases of cystic meningioma in children are presented. The MR imaging features of each case presented difficulties in differential diagnosis because of the cystic nature of the neoplasms and their location. Cystic areas in meningiomas are encountered more frequently in children than in adults. Meningioma must be included in the differential diagnosis of cystic intracranial tumors in children.

Cystic meningiomas: a review

Cystic meningiomas are uncommon tumors that are easily confused with metastatic or glial tumors that have cystic components. We have retrospectively reviewed all of the meningiomas operated on at the University of Puerto Rico in a 5-year period (1989-1993) and found only five cystic meningiomas (4.3% of total meningiomas). There is still debate about the etiology of the cyst wall; thus, multiple biopsies and frozen sections are recommended. Magnetic resonance imaging has improved diagnostic accuracy with its ability to demonstrate the dural attachment of the tumor.

Meningiomas

This article reviews the recent literature on the pathogenesis and pathology of meningiomas, contemporary techniques of surgical resection, and new nonsurgical treatments, including radiation and hormone therapy. Factors predisposing to meningioma formation include female sex, previous ionizing radiation, and Type 2 neurofibromatosis. The first factor may act through the expression of sex hormone receptors, especially the progesterone receptor, in these tumors; the other two probably act by causing a deletion on Chromosome 22. The pathological classifications of meningiomas include the traditional division into histological subtypes and the World Health Organization classification that selects characteristics that may lead to recurrence. There is an increasing emphasis on proliferative indices and other characteristics that may predict aggressive behavior in these tumors. On computed tomography, meningiomas are enhancing, well-marginated, dural-based lesions that may have considerable surrounding edema; the cause of the edema is uncertain but may result from secretory products of the tumor. Magnetic resonance imaging with enhancement will demonstrate these lesions accurately and can be used for three-dimensional reconstruction as well. Computed tomography and magnetic resonance imaging have largely replaced angiography in the preoperative diagnosis of meningiomas, but angiographic embolization may be a useful operative adjunct. Although meningioma surgery is sometimes thought of as benign and curative, the reported surgical mortality rate is as high as 14.3% and the reported 10-year survival rate after surgery varies from 43 to 77%. Surgery has advanced most in the management of suprasellar, cavernous sinus, clivus, tentorial, and posterior fossa meningiomas, because new approaches and a better understanding of anatomy have allowed more radical resection. There is still substantial morbidity associated with surgery in these regions, however, and the long-term recurrence rates are still unknown for these new radical techniques. For convexity, parasagittal, lateral sphenoid wing, and olfactory groove meningiomas, complete resection should be the goal and operative morbidity appears to be low. There is a high recurrence rate after surgery. With apparent total removal, the recurrence rate varies from 9 to 20% at 10 years, with subtotal resection varying from 18.4 to 50%. The degree of resection appears to be most important in recurrence, but histopathological features are also important. Recently, radiation therapy has been recognized as a useful adjunct to surgery, and with radiosurgical techniques may become more important in the future. Antiprogesterone therapy appears to have had some success as well, and it or other hormonal therapy may be another future option for residual or recurrent meningiomas.

Cystic meningioma: report of three patients

Three patients with cystic meningioma are reported. The computed tomographic scans or magnetic resonance images of these tumors resembled those of a glial or metastatic tumor with cystic or necrotic changes. There is no definitive method for preoperatively differentiating cystic meningiomas from the more common malignant glioma. Angiographic evaluation and collaboration with a neuropathologist are important for the recognition of these potentially curable neoplasms.

Optic nerve sheath meningioma. Definition of intraorbital, intracanalicular, and intracranial components with magnetic resonance imaging

Magnetic resonance imaging with fat saturation after the administration of gadolinium-DTPA can detect and demarcate meningioma of the optic nerve sheath with a precision not attainable with any other current imaging technique. This article describes some of the clinical implications of this technique and illustrates the appearance of this tumor on magnetic resonance images.

Large cystic intraparenchymal brain metastasis from prostate cancer

A large, cystic, intraparenchymal brain metastasis from prostate cancer is reported. The clinical and radiological features of prostate carcinoma metastatic to the brain parenchyma are reviewed.

Cystic meningiomas

Five cases of meningiomas associated with cysts are reported. In a review of the literature the authors stress the importance and difficulty of the preoperative accurate diagnosis and the differential diagnosis from other cystic tumours to avoid misdiagnosis.