Natural History, Multimodal Management, and Quality of Life Outcomes of Trigeminal Schwannomas

A, Rao KVLN, Somanna S. Surgical Management of Large (≥3 cm) Trigeminal Schwannomas: Functional Outcomes and Approach Selection in Multicompartmental Schwannomas

Introduction  Trigeminal schwannoma surgery has shown a remarkable improvement in functional recovery and tumor resection. In the era of radiosurgery, these outcomes need to be characterized for tumors which are outside the realm of being treated with radiosurgery. We present a series of trigeminal schwannomas larger than 3 cm, surgical approaches used, and outcomes with an emphasis on functional recovery in a high-volume center with radiosurgery facilities. Method  All consecutive cases of trigeminal schwannoma from January 2012 to May 2021 which were more than 3 cm in size and underwent microsurgery were included in this series. The surgical approach, neurological outcomes, and extent of resection were defined objectively with pre/postoperative magnetic resonance imaging. Results  A total of 83 such cases (>3 cm) were found, with cranial nerve symptoms (5th most common) being the commonest. Twenty three percent cases had blindness due to secondary optic atrophy and eighteen percent had long tract motor symptoms signifying the tumor burden in our series. Radiological gross total excision was achieved in 75.9% cases. Conclusion  Large-volume schwannomas present with cranial nerve involvement and may need extensive skull base approaches. Functional outcomes need to be prioritized and can be achieved albeit with lesser gross resection rates. Hearing and facial preservation in addition to relief of trigeminal symptoms should be the goal of resection with minimal additional morbidity.

Outcomes following surgical resection of trigeminal schwannomas: a systematic review and meta-analysis

Although typically benign, trigeminal schwannomas (TS) may require surgical resection when large or symptomatic and can cause significant morbidity. This study aims to summarize the literature and synthesize outcomes following surgical resection of TS. A systematic review was performed according to PRISMA guidelines. Data extracted included patient and tumor characteristics, surgical approaches, and postoperative outcomes. Odds ratios (OR) with corresponding 95% confidence intervals (CI) were used for outcome analysis. The initial search yielded 1838 results, of which 26 studies with 974 patients undergoing surgical resection of TS were included. The mean age was 42.9 years and 58.0% were female. The mean tumor diameter was 4.7 cm, with Samii type A, B, C, and D tumors corresponding to 33.4%, 15.8%, 37.2%, and 13.6%, respectively. Over a mean symptom duration of 29 months, patients presented with trigeminal hypesthesia (58.7%), headache (32.8%), trigeminal motor weakness (22.8%), facial pain (21.3%), ataxia (19.4%), diplopia (18.7%), and visual impairment (12.0%). Surgical approaches included supratentorial (61.4%), infratentorial (15.0%), endoscopic (8.6%), combined/staged (5.3%), and anterior (5.7%) or posterior (4.0%) petrosectomy. Postoperative improvement of facial pain (83.9%) was significantly greater than trigeminal motor weakness (33.0%) or hypesthesia (29.4%). The extent of resection (EOR) was reported as gross total (GTR), near total, and subtotal in 77.7%, 7.7%, and 14.6% of cases, respectively. Over a mean follow-up time of 62.6 months, recurrence/progression was noted in 7.4% of patients at a mean time to recurrence of 44.9 months. Patients with GTR had statistically significantly lower odds of recurrence/progression (OR: 0.07; 95% CI: 0.04-0.15) compared to patients with non-GTR. This systematic review and meta-analysis report patient outcomes following surgical resection of TS. EOR was found to be an important predictor of the risk of recurrence. Facial pain was more likely to improve postoperatively than facial hypesthesia. This work reports baseline rates of post-operative complications across studies, establishing benchmarks for neurosurgeons innovating and working to improve surgical outcomes for TS patients.

[Trigeminal neuromas: modern diagnosis and treatment]

Trigeminal neuroma (TN) is a benign neoplasm arising from trigeminal nerve sheath. The tumor can grow from any part of the nerve from the root in posterior cranial fossa to peripheral extracranial branches. Symptoms of trigeminal neuroma are variable and usually depend on location and dimensions of tumor. We present a review devoted to the problem of TN. Surgery was the only possible option in patients with TN for a long time. However, radiotherapy became one of the options and sometimes alternative to surgical treatment since the late 1980s. Besides active management of patients with TN, follow-up with regular radiographic control of small asymptomatic tumors also seems to be reasonable. When evaluating treatment outcomes, physicians consider quality of life and return to previous work and activity in addition to resection quality, neurological impairment, relapse-free period and tumor growth control. However, assessment of these indicators after certain treatment is rare. Thus, it is difficult to determine treatment strategy with maximum ratio of effectiveness and quality of life. Therefore, optimization of TN treatment is currently an urgent problem that requires further study.

Management of non-vestibular schwannomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section Part II: Trigeminal and facial nerve schwannomas (CN V, VII)

BACKGROUND

Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations.

METHODS

A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the second of a three-part series describing non-vestibular schwannomas (V, VII).

RESULTS

A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to pre-operative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies, and follow-up management.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the treatment of trigeminal and facial schwannoma. The aim of treatment is maximal safe resection with preservation of function. Careful thought is required to select the appropriate surgical approach. Most middle fossa trigeminal schwannoma tumours can be safely accessed by a subtemporal extradural middle fossa approach. The treatment of facial nerve schwannoma remains controversial.

Pediatric multicompartmental trigeminal schwannoma: illustrative case

BACKGROUND

Trigeminal schwannoma (TS) is an uncommon and histologically benign intracranial lesion that can involve any segment of the fifth cranial nerve. Given its often impressive size at diagnosis and frequent involvement of critical neurovascular structures of the skull base, it represents a challenging entity to treat. Pediatric TS is particularly rare and presents unique challenges. Similarly, tumors with extension into multiple compartments (e.g., middle cranial fossa, posterior cranial fossa, extracranial spaces) are notoriously difficult to treat surgically. Combined or staged surgical approaches are typically required to address them, with radiosurgical treatment as an adjunct.

OBSERVATIONS

The authors presented the unusual case of a 9-year-old boy with a large, recurrent multicompartmental TS involving Meckel’s cave, the cerebellopontine angle, and the infratemporal fossa. Near-total resection was achieved using a frontotemporal-orbitozygomatic craniotomy with a combined interdural and extradural approach.

LESSONS

The case report adds to the current literature on multicompartmental TSs in children and their management. The authors also provided a simplified classification of TS that can be generalized to other skull base tumors. Given a lack of precedent, the authors intended to add to the discussion regarding surgical management of these rare and challenging skull base lesions.

Trends in the Management of Non-Vestibular Skull Base and Intracranial Schwannomas

The aim of this review is to analyze the latest trends in the management of non-vestibular skull base and intracranial schwannomas in order to optimize tumor control and quality of life. Non-vestibular cranial nerve schwannomas are rare lesions, representing 5–10% of cranial nerve schwannomas. Management decisions should be individualized depending on tumor size, location and associated functional deficits. Generally, large sized schwannomas exerting significant mass effect with increased intracranial pressure are treated surgically. In some cases, even after optimal skull base resection, it is not possible to achieve a gross total resection because tumor location and extent and/or to reduce morbidity. Thus, subtotal resection followed by stereotactic radiosurgery or fractioned radiotherapy offers an alternative approach. In certain cases, stereotactic radiosurgery or radiotherapy alone achieves good tumor control rates and less morbidity to gross total resection. Finally, given the slow growth rate of most of these tumors, observation with periodic radiographic follow-up approach is also a reasonable alternative for small tumors with few, if any, symptoms.

"Apoplectic" Recurrence of Massive Trigeminal Neurinomas: Report of 7 Cases

OBJECTIVE

The pattern of recurrence of large trigeminal neurinomas is analyzed on the basis of experience with 7 cases.

METHODS

This is a report of 7 cases of large trigeminal neurinomas that were operated on an average of 11 years earlier. After being relatively asymptomatic over the years, these patients worsened relatively suddenly in their neurologic symptoms and were reoperated.

RESULTS

Imaging showed massive recurrence with tumor having cystic and solid components with sizes ranging from 4.5-11 cm. In 4 cases, the cysts at the time of initial presentation and at the time of recurrence showed a well-defined fluid level within the fluid content of the cyst. During operation it was seen that the tumor contained "hemorrhagic" fluid that was under significant pressure. The solid component in the circumferential periphery of the cyst fluid was soft, necrotic, and vascular. The entire recurrence in the middle and posterior cranial fossa and in the extracranial compartment was "interdural" or within the dural confines. Radical tumor resection within the dural confines by deploying relatively small surgical exposure resulted in "unusually" rapid recovery in the symptoms. Histological examination of the tumor did not reveal any malignant transformation.

CONCLUSIONS

The cases add further insight to the growth pattern and characteristics of large trigeminal neurinomas.