Meningioma

Intraparenchymal schwannoma with calcification of the temporal lobe: Case report and literature review

RATIONALE

Intracranial schwannomas most frequently arise from the trigeminal nerve and the vestibular nerve. Schwannomas within the cerebral parenchyma are exceedingly rare. Additionally, calcification is an uncommon histopathological and radiological characteristic in schwannomas.

PATIENT CONCERNS

A 46-year-old man presented to us with sudden onset epileptic seizure and a 3-month history of intermittent headache. After admission, the physical and neurological examinations were all normal. Brain CT revealed an irregular, well-defined, hyperdense mass in the right temporal lobe. MRI showed a solid mass appearing iso- to hypointensity on T1-weighted imaging and heterogeneous intensity on T2-weighted imaging in the right temporal lobe; after Gd-DTPA administration, the lesion showed heterogeneous enhancement.

DIAGNOSIS

Histopathological examination revealed hyperchromatic nuclei and loose intercellular matrix with calcification. Immunohistochemical analysis demonstrated that the tumor was strongly positive for S100 protein but negative for GFAP and CK, which was consistent with a schwannoma.

INTERVENTIONS AND OUTCOMES

A surgical resection via the right temporal approach was performed. Intraoperatively, we noticed that the tumor was grayish yellow, capsuled, and located entirely within the temporal parenchyma. A gross total resection was achieved. The postoperative course was uneventful, and there was no epileptic seizure.

LESSONS

Intraparenchymal schwannoma with calcification is an uncommon histopathological and radiological characteristic in schwannomas. Intraparenchymal schwannoma with calcification is extremely rare. The early identification and appropriate surgical treatment should be highlighted.

Temozolomide Combined with Radiotherapy in the Treatment of Recurrent Cranial Meningioma Previously Treated with Multiple Surgical Resections and Two Sessions of Radiosurgery: A Case Report and Literature Review

Meningioma is a common primary brain tumor in adults. The treatment approach depends on its grade, size and symptoms. The case reported here was a repeatedly recurring transitional meningioma, previously treated with several surgical procedures and two sessions of cranial radiosurgery. At the time of last relapse, temozolomide was administered alone and combined with external beam radiation therapy. At the last follow-up after 38 months, the disease was stable. In conclusion, in this case of plurirecurrent meningioma, treatment with temozolomide alone and in combination with radiotherapy was feasible and associated with limited morbidity, providing clinical benefit and long local disease control. We discuss the case comparing our approach with other experiences reported in the literature.

EANO guidelines for the diagnosis and treatment of meningiomas

Although meningiomas are the most common intracranial tumours, the level of evidence to provide recommendations for the diagnosis and treatment of meningiomas is low compared with other tumours such as high-grade gliomas. The meningioma task force of the European Association of Neuro-Oncology (EANO) assessed the scientific literature and composed a framework of the best possible evidence-based recommendations for health professionals. The provisional diagnosis of meningioma is mainly made by MRI. Definitive diagnosis, including histological classification, grading, and molecular profiling, requires a surgical procedure to obtain tumour tissue. Therefore, in many elderly patients, observation is the best therapeutic option. If therapy is deemed necessary, the standard treatment is gross total surgical resection including the involved dura. As an alternative, radiosurgery can be done for small tumours, or fractionated radiotherapy in large or previously treated tumours. Treatment concepts combining surgery and radiosurgery or fractionated radiotherapy, which enable treatment of the complete tumour volume with low morbidity, are being developed. Pharmacotherapy for meningiomas has remained largely experimental. However, antiangiogenic drugs, peptide receptor radionuclide therapy, and targeted agents are promising candidates for future pharmacological approaches to treat refractory meningiomas across all WHO grades.

Systemic therapy for recurrent meningioma

INTRODUCTION

Meningioma comprise 20-30% of all primary brain tumors. Notwithstanding surgery and radiotherapy, a subset of patients will manifest recurrent meningioma. Systemic therapy is recommended only when further surgery and radiotherapy are not possible. No prospective study with a high level of evidence is available to inform as to recommendations regarding systemic therapy.

AREAS COVERED

We aim to summarize systemic therapies for recurrent meningioma. Expert commentary: Hydroxurea, temozolomide, irinotecan, the combination of cyclophosphamide/adriamycine/vincristine, interferon-alpha, somatostatin analogs, mifepristone, megestrol acetate, imatinib, erlotinib and gefitinib are considered as having limited efficacy. Potential activity of VEGF (vascular endothelial growth factor) inhibitors such as sunitinib, valatinib, and bevacizumab is suggested in small non-controlled studies and requires validation in randomized trials. The identification of new prognostic markers such as TERT promoter mutations and potential new therapeutic targets, such as KLF4, AKT1, TRAF7, and SMO mutations hopefully facilitate this endeavor.

IFN-α for recurrent surgery- and radiation-refractory high-grade meningioma: a retrospective case series

AIM

Limited literature is available regarding the treatment of recurrent surgery- and radiation-refractory meningioma, and it primarily examines the treatment of low-grade (WHO grade 1) meningioma. Data regarding systemic therapy for recurrent high-grade meningioma are sparse. A retrospective case series of patients with recurrent WHO grade 2/3 meningioma treated with IFN-α following progression after surgery, radiotherapy and hydroxyurea was carried out, with the primary study objective of overall response rate, and median and 6-month progression-free survival (PFS).

PATIENTS & METHODS

35 patients (28 women and 17 men; median age 63 years; range: 36-86 years) with recurrent high-grade meningioma (WHO grade 2 [n = 22] or 3 [n = 13]) were treated with IFN-α (10 million units/m(2)) subcutaneously every 2 days; one cycle was operationally defined as 4 weeks of IFN-α. Patients had progressed radiographically after prior therapy with surgery (35 out of 35), radiotherapy (35 out of 35; external-beam radiotherapy: 35 out of 35; and stereotactic radiotherapy: 34 out of 35) and hydroxyurea chemotherapy (35 out of 35). One patient was also treated with a somatostatin analog before initiating IFN-α treatment.

RESULTS

Patients received one to 13 cycles (median: three) of IFN-α with moderate toxicity (100% of patients manifested grades 1-3 toxicity, of which only 20% were grade 3). There were no radiographic responses, 63% of patients had stable disease and 37% manifested progressive disease at first evaluation. PFS was 17% at 6 months (95% CI: 0.07-0.31; median PFS: 12 weeks; 95% CI: 8-20 weeks; range: 4-52 weeks). Following progression on IFN-α, the majority of patients (60%) were subsequently treated on an alternative therapy.

CONCLUSION

In this large retrospective series, IFN-α was moderately toxic, but appeared to have limited activity in patients with recurrent high-grade meningiomas.

Management of petroclival meningiomas: a review of the development of current therapy

The surgical management of petroclival meningioma remains challenging, due to the difficulty of accessing the region and the vital structures adjacent to the origin of these tumors. Petroclival meningiomas were originally considered largely unresectable. Until the 1970s, resection carried a 50% mortality rate, with very high rates of operative morbidity if attempted. However, in the past 40 years, advances in neuroimaging and approaches to the region were refined, and results from resection of petroclival meningiomas have become more acceptable. Today, the developments of a multitude of surgical approaches as well as innovations in neuroimaging and stereotactic radiotherapy have proved powerful options for multimodality management of these challenging tumors.

Novel therapies for meningiomas

Although advances in surgery, radiation therapy and stereotactic radiosurgery have significantly improved the treatment of meningiomas, there remains an important subset of patients who remain refractory to conventional therapy. Treatment with chemotherapeutic agents such as hydroxyurea and alpha-interferon has provided minimal benefit. In this review, the role of newly emerging novel therapies for meningiomas, with a focus on targeted molecular agents, will be discussed.

Impact of anterior clinoidectomy on visual function after resection of meningiomas in and around the optic canal

BACKGROUND

Meningiomas of the anterior and middle skull base frequently involve the optic nerve and cause progressive visual impairment. Surgical decompression of the optic nerve is the only option to preserve visual function. Depending on the invaded structures, optic nerve decompression can be part of a complete tumor removal or the main surgical intention in terms of local debulking. However, bony decompression of the optic canal including anterior clinoidectomy for optic nerve decompression is still a surgical maneuver under discussion.

METHODS

From 2006 to 2011, 46 consecutive patients with skull base meningiomas in and around the optic canal were operated. The pterional approach was tailored for each patient. Resection included bony decompression of the optic canal with or without anterior clinoidectomy. Visual acuity and fields were evaluated pre- and postoperatively.

RESULTS

Fifty-three percent of patients underwent anterior clinoidectomy, 23 % optic canal unroofing, and 24 % any bony decompression. In 21 patients (46 %), gross total resection (GTR, Simpson grade I or II) was achieved, while 25 patients (54 %) received subtotal resection (STR, Simpson grade III or IV). Sixty-three percent of patients presented with preoperative visual impairment. Postoperative visual changes were significantly related to preoperative visual function. While all patients with normal preoperative vision remained unchanged, in patients with impaired vision, surgery caused improvement in 70 % and deterioration in 10 % of patients (p < 0.0001). In patients with anterior clinoidectomy, vision improved more frequently than without anterior clinoidectomy (p < 0.05).

CONCLUSIONS

Anterior clinoidectomy is safe and may improve visual outcome in meningiomas in and around the optic canal.

Calcification of vestibular schwannoma: a case report and literature review

Calcification rarely occurs in vestibular schwannoma (VS), and only seven cases of calcified VS have been reported in the literature. Here, we report a 48-year-old man with VS, who had a history of progressive left-sided hearing loss for 3 years. Neurological examination revealed that he had left-sided hearing loss and left cerebellar ataxia. Magnetic resonance imaging and computerized tomography angiography showed a mass with calcification in the left cerebellopontine angle (CPA). The tumor was successfully removed via suboccipital craniotomy, and postoperative histopathology showed that the tumor was a schwannoma. We reviewed seven cases of calcified VS that were previously reported in the literature, and we analyzed and summarized the characteristics of these tumors, including the calcification, texture, and blood supply. We conclude that calcification in VS is associated with its texture and blood supply, and these characteristics affect the surgical removal of the tumor.

Hydroxyurea for recurrent surgery and radiation refractory high-grade meningioma

Hydroxyurea (HU), an orally administered chemotherapy, has become the de facto standard chemotherapeutic agent in patients with surgically and radiation refractory meningiomas based on a limited literature. A retrospective case series of 35 patients with recurrent WHO Grade 2 (n = 22) or 3 (n = 13) meningioma treated with HU following progression after surgery and radiotherapy was collated with primary study objectives of overall response rate, median and progression free survival (PFS) at 6-months. Thirty-five patients (25 women; 10 men: median age 63 years, range 34-86) with recurrent high-grade meningioma were treated with HU (1,000 mg/m(2) orally divided twice per day; one cycle operationally defined as 4 weeks of daily HU). Patients had progressed radiographically after prior therapy with surgery (35/35) and radiotherapy (35/35: external beam radiotherapy 35/35; stereotactic radiotherapy 35/35). No patient received prior chemotherapy or targeted therapy before instituting HU. Patients received 0.5-7 cycles (median 2.0) of HU with modest toxicity (28.5% all grades and 8.5% grade 3+ anemia or fatigue). There were no radiographic responses, 43% of patients had stable disease and 57% manifested progressive disease at first evaluation. The overall PFS was 3.0% at 6 months (median PFS 2.0 months; 95% CI 1.6-2.4). The majority of patients (80%) following progression on HU were subsequently treated on an investigational trial. In this retrospective series, HU though well tolerated and convenient appeared to have very limited activity, raise questions of what constitutes effective salvage therapy and indicates an unmet need for alternative treatments for recurrent high-grade meningiomas.

Hydroxyurea for recurrent surgery and radiation refractory meningioma: a retrospective case series

Hydroxyurea (HU), an orally administered chemotherapy, has become the de facto standard therapeutic agent in patients with surgically and radiation refractory meningiomas based on a limited literature. A retrospective case series of 60 patients with recurrent WHO grade 1 meningioma treated with HU following progression after surgery and radiotherapy was conducted with primary study objective progression free survival (PFS) at 6- and 12-months. Sixty patients (45 women; 15 men: median age 61.5 years, range 26-88) with recurrent meningioma were treated with HU (1000 mg/m(2)/day orally divided twice per day; one cycle operationally defined as 4-weeks of daily HU). All patients had progressed radiographically after prior therapy with surgery (60/60) and radiotherapy (external beam radiotherapy 60/60; stereotactic radiotherapy 53/60). No patient received prior chemotherapy or targeted therapy before instituting HU. Patients received 1-12 cycles (median 2.0) of HU with modest toxicity (10% grade 3 + anemia or fatigue). There were no radiographic responses, 35% of patients had stable disease and 65% manifested progressive disease. Duration of stable disease ranged from 3 to 12 months (median 4.0 months). The overall PFS was 10% (median PFS 2.0 months). The majority of patients (80%) following progression on HU were subsequently treated on an investigational trial. In this retrospective case series, HU though generally well tolerated and convenient, appeared to have very limited activity which raises questions of what constitutes effective salvage therapy and indicates an unmet need for alternative treatments for recurrent meningiomas.

Medical therapies for meningiomas

Meningiomas are the most common primary brain tumor in adults. Although the majority of these tumors can be effectively treated with surgery and radiation therapy, an important subset of patients have inoperable tumors, or develop recurrent disease after surgery and radiotherapy, and require some form of medical therapy. There are increasing numbers of studies evaluating various medical therapies but the results remain disappointing. Chemotherapies and hormonal therapies have been generally ineffective, although somatostatin analogues may have therapeutic potential. There is also increasing interest in targeted molecular therapies. Agents inhibiting platelet derived growth factor receptors and epidermal growth factor receptors have shown little efficacy, but molecular agents inhibiting vascular endothelial growth factor receptors appear to have some promise. As with other tumors, advances in the medical therapies for meningiomas will require improved understanding of the molecular pathogenesis of these tumors, more predictive preclinical models, and efficient mechanisms for conducting clinical trials, given the small population of eligible patients.

Stereotactic radiosurgery for skull base meningioma

Stereotactic radiosurgery is now a treatment option for meningiomas, especially for high-risk patients such as those with skull base lesions. The clinical outcomes were retrospectively analyzed of stereotactic radiosurgery using the Leksell Gamma Knife((R)) performed for 98 patients with 106 skull base meningiomas at the University of Tokyo Hospital between June 1990 and April 2006 and followed up for more than a year. After a median follow-up period of 53.2 months (range 12.2-204.4 months), local tumor control rates were 86.9% and 78.9% at 5 years and 10 years, respectively. Tumors with volume of 4 cm(3) or smaller (97.5% vs. 76.1% at 5 years, p = 0.001) and tumors completely included within the isodose line of 14 Gy or more (97.5% vs. 67.2% at 5 years, p = 0.0006) had higher local control rates. Postoperative residual tumors treated by stereotactic radiosurgery were controlled in all 25 cases. Cranial nerve deficits were improved, stable, and deteriorated in 12, 64, and 3 patients, respectively, after stereotactic radiosurgery. Stereotactic radiosurgery was effective treatment method for local control of skull base meningiomas, especially for small or postoperative residual tumors. Correct combination of microsurgery and radiosurgery leads to excellent local control.

Rare sellar lesions

Sellar masses are associated most commonly with pituitary adenomas. Many other neoplastic, inflammatory, infectious, and vascular lesions, however, may affect the sellar region and mimic pituitary tumors. These lesions must be considered in a differential diagnosis. This article describes the characteristics of rare sellar masses that provide clues to their differential diagnosis.

Foramen magnum meningioma: Dysphagia of atypical etiology

INTRODUCTION

We present a case of a foramen magnum meningioma that highlights the importance of the neurologic exam when evaluating a patient with dysphagia. A 58-year-old woman presented with an 18-month history of progressive dysphagia, chronic cough and 30-pound weight loss. Prior gastroenterologic and laryngologic workup was unrevealing.

RESULTS

Her neurologic examination revealed an absent gag reflex, decreased sensation to light touch on bilateral distal extremities, hyperreflexia, and tandem gait instability. Repeat esophagogastroduodenoscopy was normal, whereas laryngoscopy and video fluoroscopy revealed marked hypopharyngeal dysfunction. Brain magnetic resonance imaging demonstrated a 3.1 x 2.7 x 2.9 cm foramen magnum mass consistent with meningioma. The patient underwent neurosurgical resection of her mass with near complete resolution of her neurologic symptoms. Pathology confirmed diagnosis of a WHO grade I meningothelial meningioma.

CONCLUSION

CNS pathology is an uncommon but impressive cause of dysphagia. Our case demonstrates the importance of a thorough neurologic survey when evaluating such a patient.

Targeted drug therapy for meningiomas

✓ Although advances in surgery, radiation therapy, and stereotactic radiosurgery have significantly improved the treatment of meningiomas, there remains an important subset of patients whose tumors are refractory to conventional therapy. Treatment with traditional chemotherapeutic agents has provided minimal benefit. In this review, the role of targeted molecular therapies for recurrent or progressive meningiomas is discussed.