Abstract
BACKGROUND AND OBJECTIVES:
Cavernous sinus meningiomas (CSMs) are surgically challenging due to their proximity to the internal carotid artery and multiple cranial nerves, and long-term visual trajectories after treatment remain incompletely characterized. This study aimed to define mid- to long-term outcomes, with an emphasis on temporal patterns of visual change, in patients undergoing surgical treatment for CSMs.
METHODS:
We retrospectively analyzed 30 patients with CSM who underwent initial surgical treatment between April 2004 and October 2024. Clinical, radiological, and pathological data were reviewed, including surgical approach, extent of resection, optic canal decompression, complications, adjuvant radiotherapy, tumor control, visual outcomes, and Karnofsky Performance Status score. Extent of resection was calculated volumetrically using contrast-enhanced magnetic resonance imaging. Visual outcomes were evaluated at 4 to 6 months postoperatively and at final follow-up.
RESULTS:
The median age was 56 years, and 76.7% were women. Radical intracavernous resection was not attempted. Optic canal decompression was performed in 20 patients. World Health Organization grade 1 tumors accounted for 92.6% of cases. Median follow-up was 81.0 months, and the mean number of surgeries was 1.7 per patient. Early visual improvement was observed in 7 of 11 patients (63.6%) with preoperative deficits. Four patients (13.3%) developed severe visual deterioration to perception of hand motion or worse, with a mean time to event of 94 months; all had received radiotherapy. Tumor irradiation with radiosurgery or radiotherapy provided durable tumor control in selected cases but was associated with higher rates of progression, reflecting selection bias. The mean final Karnofsky Performance Status score was 81.0.
CONCLUSION:
These findings suggest the possibility of a biphasic visual trajectory after surgical management of CSM. Optic canal decompression may facilitate early visual improvement, although delayed visual deterioration can occur despite prolonged disease control, as observed in a limited number of patients. A function-preserving, multimodal strategy may optimize long-term outcomes.
KEY WORDS: Cavernous sinus meningioma, Long-term outcome, Optic canal decompression, Surgical management, Visual function
ABBREVIATIONS:
- EOR
extent of resection
- HRs
hazard ratios
- IMRT
intensity-modulated radiation therapy
- KPS
Karnofsky Performance Status
- WHO
World Health Organization.
Cavernous sinus meningiomas (CSMs) are among the most challenging intracranial tumors to treat because of the complex anatomy of the region in which they arise, which encompasses the internal carotid artery and multiple cranial nerves (CNs) within the cavernous sinus.1,2 Surgical management of CSMs is therefore associated with a high risk of neurological morbidity and vascular injury. Although several reports have described radical resection of the portion of the tumor within the cavernous sinus using adjunctive techniques such as high-flow bypass,3,4 these aggressive approaches are highly invasive and carry a substantial risk of postoperative complications that may compromise quality of life. Moreover, tumor recurrence has been reported even after almost complete resection.5-9
Radiotherapy of CSMs can achieve acceptable progression-free survival and overall survival rates with lower morbidity than resection.10-13 Consequently, most neurosurgeons avoid attempting radical resection. CSMs are generally benign and slow-growing, and mild symptoms can usually be adequately controlled with conservative management alone.14 Therefore, the indications for surgical removal of CSMs are controversial. Treatment is typically individualized based on patient age, clinical symptoms, tumor growth rate, and tumor extension. The main options include surgery, radiotherapy, or observation with serial imaging.15-18 Tumor progression can lead to a variety of neurological deficits, among which visual dysfunction has a particularly profound impact on quality of life. In this study, we report the outcomes of surgically treated CSM at our institution, with a particular focus on visual and CN function.
METHODS
Patients with CSM who underwent surgical treatment at our institution between April 2004 and October 2024 were retrospectively reviewed. This study was approved by the institutional review board of our institution (approval no. 20130379). Written informed consent for surgical treatment was obtained from all patients. The requirement for informed consent for participation in this retrospective study was waived through an opt-out process approved by the institutional review board. CSMs typically originate from the dura of the cavernous sinus itself; however, some tumors arise from adjacent dura mater and secondarily invade the cavernous sinus.17 Several studies have distinguished secondary cavernous sinus invasion from primary CSM.19 In this study, we reviewed medical records of patients who underwent surgery at our institution during the study period and had radiological evidence of tumor involvement within the cavernous sinus at the time of initial presentation. The surgical approach was determined by the operating neurosurgeon based on the direction of tumor extension. Clinical data, including patient age and sex, preoperative symptoms, pathological diagnosis, MIB-1 labeling index, surgical approach, postoperative improvement or deterioration of symptoms, postoperative complications, tumor control, use of adjuvant radiotherapy, final visual outcome (deterioration to perception of hand motion or worse), and final Karnofsky performance status (KPS) score, were obtained from electronic medical records and analyzed. For patients who underwent multiple surgeries, data were analyzed based on the initial surgical procedure. Among an initial cohort of 37 patients, 5 who had undergone their first surgery at another institution and 2 whose follow-up was ≤3 months were excluded. Therefore, 30 patients were included for analysis.
Optic canal decompression was defined as surgical removal of bone overlying the optic nerve within the optic canal to relieve compression. In transcranial approaches, this involved drilling of the roof and medial wall of the optic canal after removal of the anterior clinoid process. In transnasal endoscopic approaches, decompression was achieved by removal of the medial wall and floor of the optic canal.
Extent of resection (EOR) was calculated as (preoperative tumor volume − postoperative residual tumor volume)/preoperative tumor volume × 100% and classified as subtotal resection (>90%), partial resection (50%-90%), partial resection (10%-49%), or biopsy (<10%). Tumor volume was measured on preoperative and postoperative contrast-enhanced magnetic resonance imaging using Vincent software (Fujifilm Corp.).
Radiotherapy during follow-up was defined as tumor irradiation (including radiosurgery and fractionated radiotherapy) administered at any time during the observation period, regardless of indication, including both planned postoperative radiotherapy and salvage radiotherapy for tumor progression. Visual progression-free survival (PFS) was defined as the time from surgery to visual deterioration to perception of hand motion or worse. Patients who did not experience visual deterioration to hand motion or worse were censored at the time of last follow-up. PFS was defined as the time from surgery to radiological tumor progression that required additional intervention (reoperation or salvage radiotherapy). Patients who had radiographic progression managed conservatively were not classified as having a PFS event; patients without qualifying progression were censored at the time of last follow-up. Planned postoperative radiotherapy was defined as radiotherapy performed within 1 year of surgery in the absence of radiological tumor progression and was not counted as a PFS event. Radiotherapy administered as salvage treatment for documented tumor progression was considered an event.
Categorical variables are presented as counts and percentages and were compared using Fisher's exact test. Unless otherwise indicated, continuous variables are presented as medians with IQR or means with range, as appropriate, and were compared using the Wilcoxon rank-sum test. PFS and visual PFS were estimated using the Kaplan–Meier method and compared using the log-rank test. Univariate Cox proportional hazards regression was performed to evaluate associations between clinicopathological variables and PFS or visual PFS; results are reported as hazard ratios (HRs) with 95% CIs. Variables with complete separation (all events occurring within one category) were reported as not estimable. Median follow-up was estimated using the reverse Kaplan–Meier method. P < .05 was considered significant. Statistical analyses were performed using R software (www.r-project.org).
RESULTS
Demographic Characteristics
Among the 30 patients included for analysis, 23 were women (76.7%). Median age at the time of the initial surgery was 56 years (range, 28-75). Patient characteristics are summarized in Table 1. Although some tumors were detected incidentally, most preoperative symptoms were related to dysfunction of CNs located within the cavernous sinus region.
TABLE 1.
Patient and Tumor Characteristics
| Characteristics | Value |
|---|---|
| Sex (%) | |
| Male | 7 (23.3) |
| Female | 23 (76.7) |
| Median age, y (range) | 56 (28-75) |
| Presenting symptoms (%) | |
| Headache | 3 (10.0) |
| CN palsy (CN III-VI) | 8 (26.7) |
| Trigeminal neuralgia | 4 (13.3) |
| Visual loss | 11 (36.7) |
| Dizziness | 1 (3.3) |
| Aphasia | 1 (3.3) |
| Pathologya (%) | |
| WHO grade 1 | 25 (92.6) |
| WHO grade 2 | 2 (7.4) |
| WHO grade 3 | 0 (0) |
| MIB-1 indexa (%) | |
| 0%-3% | 11 (73.3) |
| 4%-10% | 3 (20.0) |
| >10% | 1 (6.7) |
CN, cranial nerve; WHO, World Health Organization.
Percentages for pathology and MIB-1 index were calculated using only cases with available data.
Histopathological diagnosis revealed World Health Organization (WHO) grade 1 meningioma in 25 patients (92.6%) and WHO grade 2 in 2 patients (7.4%); grade was not available in 3 patients. Notably, CDKN2A/B homozygous deletion was identified on genetic analysis of a recurrent tumor specimen in one patient, indicating WHO grade 3.20
Surgical Procedure
Surgical approaches, optic canal decompression, and EOR are summarized in Table 2.
TABLE 2.
Surgical Procedure
| Surgical approaches | Value (%) | Optic canal decompression | Extent of resection | |||
|---|---|---|---|---|---|---|
| Subtotal resection (>90%) | Partial resection (50%-90%) | Partial resection (10%-49%) | Biopsy (<10%) | |||
| Transnasal | 4 (13.3) | 3 | 0 | 0 | 1 | 3 |
| Frontotemporal | 8 (26.7) | 8 | 1 | 2 | 4 | 1 |
| Orbitozygomatic | 4 (13.3) | 2 | 0 | 4 | 0 | 0 |
| Frontotemporal + zygomatic | 8 (26.7) | 7 | 3 | 1 | 4 | 0 |
| Frontotemporal + anterior transpetrosal | 1 (3.3) | 0 | 0 | 1 | 0 | 0 |
| Anterior transpetrosal | 1 (3.3) | 0 | 0 | 0 | 1 | 0 |
| Combined transpetrosal | 3 (10.0) | 0 | 0 | 3 | 0 | 0 |
| Retrosigmoid | 1 (3.3) | 0 | 1 | 0 | 0 | 0 |
| Total | 30 | 20 | 5 | 11 | 10 | 4 |
Optic canal decompression was performed in 20 patients, including 3 who underwent biopsy with optic canal decompression alone. Radical resection of the intracavernous tumor component was not attempted. Preoperative tumor embolization was performed in 6 patients (20%).
Observation Duration and Number of Treatments
Median follow-up estimated by the reverse Kaplan–Meier method was 81.0 months (range, 4-177). Patients underwent a mean of 1.7 surgical procedures (range, 1-4), and 13 patients (43.3%) required multiple surgeries. The mean number of radiotherapy sessions was 0.7 (range, 0-6).
Radiotherapy modalities included Gamma Knife radiosurgery (5 treatments), stereotactic radiotherapy (10 treatments), and intensity-modulated radiation therapy (IMRT; 4 treatments), selected based on residual tumor volume and location. The mean marginal dose for Gamma Knife radiosurgery was 13.6 Gy (range, 12-15). The mean total doses for stereotactic radiotherapy and IMRT were 26.1 Gy (range, 21-32.9) and 55.5 Gy (range, 54-60), respectively.
Treatment Outcomes
Perioperative complications and changes in symptoms 4 to 6 months after surgery are summarized in Table 3. Perioperative complications, including transient deficits, occurred in 10 patients (33.3%).
TABLE 3.
Complications and Changes in Symptoms 4 to 6 Months After Surgery
| Complications | Value (%) |
|---|---|
| CN palsy (CN III-VI) | 7/30 (23.3) |
| Meningitis | 1/30 (3.3) |
| CSF leakage | 1/30 (3.3) |
| Cerebral infarction | 1/30 (3.3) |
| Postoperative (4-6 mo) improvement in symptoms | |
| Headache | 2/2 (100) |
| CN palsy (CN III-VI) | 1/8 (12.5) |
| Trigeminal neuralgia | 3/4 (75.0) |
| Visual loss | 7/11 (63.6) |
| Dizziness | 1/1 (100) |
| Motor aphasia | 1/1 (100) |
CN, cranial nerve; CSF, cerebrospinal fluid.
Improvement of preoperative symptoms was observed in 15 patients (50.0%), with higher recovery rates for visual impairment (7/11, 63.6%) and trigeminal neuralgia (3/4, 75.0%) than for CN palsy (1/8, 12.5%). No improvement was observed after 6 months.
Final outcomes for the radiotherapy and no radiotherapy groups are summarized in Table 4. Mean follow-ups were 109.1 months (range, 58-177) and 60.4 months (range, 4-136), respectively. Radiological tumor progression after surgery was significantly more frequent in the radiotherapy group (69.2% vs 23.5%; P = .025). Notably, 2 patients who demonstrated tumor shrinkage with sustained control were both in the radiotherapy group. Four patients experienced deterioration of visual acuity to hand motion or worse at final follow-up, with a mean time to event of 94 months (range, 26-164); all belonged to the radiotherapy group (30.8% vs 0%; P = .026). Median KPS score at final follow-up did not significantly differ between the radiotherapy and no radiotherapy groups (90 and 90, respectively; P = .320). These between-group comparisons are descriptive only, as radiotherapy was not randomly assigned but was preferentially administered to patients with more aggressive or progressive disease.
TABLE 4.
Outcomes in the Radiotherapy and No Radiotherapy Groups
| No radiotherapy group (N = 17) | Radiotherapy group (N = 13) | Overall cohort (N = 30) | P value | |
|---|---|---|---|---|
| Mean follow-up duration, mo [range] | 60.4 [4-136] | 109.1 [58-177] | 81.5 [4-177] | .002 |
| Postoperative radiological changes (%) | ||||
| Progression | 4 (23.5) | 9 (69.2) | 14 (46.7) | .025a |
| Stable | 13 (76.5) | 2 (15.4) | 14 (46.7) | |
| Regression | 0 (0) | 2 (15.4) | 2 (6.7) | |
| Visual acuity ≤ hand motion (%) | 0 (0) | 4 (30.8) | 4 (13.3) | .026 |
| KPS, median (IQR) [range] | 90 (0) [60-100] | 90 (20) [0-100] | 90 (7.5) [0-100] | .320 |
KPS, Karnofsky performance scale.
P value for progression vs no progression (stable + regression).
Follow-up duration and KPS were compared using the Wilcoxon rank-sum test. Categorical variables were compared using Fisher's exact test.
Tumor progression requiring additional treatment occurred in 7 of 25 patients in the surgery-alone group and 2 of 5 patients in the surgery plus radiotherapy group (Figure 1A). The median PFS was not reached in the surgery-alone group, whereas it was 89 months in the surgery plus radiotherapy group.
FIGURE 1.
Kaplan–Meier curves for A, progression-free survival in the surgery alone and surgery plus radiotherapy groups and B, visual progression-free survival in patients dichotomized according to optic canal decompression.
Mid- to long-term visual outcomes are summarized in Table 5. Among 19 patients without preoperative visual impairment, optic canal decompression was performed in 10 patients; 2 of these patients eventually deteriorated to hand motion or worse. Among 11 patients with preoperative visual impairment, optic canal decompression was performed in 10 patients; postoperative visual improvement was observed in 7 patients 4 to 6 months after surgery. The single patient with preoperative visual impairment who did not undergo optic canal decompression showed no improvement. Among the 7 patients who demonstrated early postoperative visual improvement, 2 patients ultimately deteriorated to hand motion or worse. The detailed clinical course of the 7 patients with early postoperative visual improvement are presented in Table 6; this group included patients treated with biopsy and optic canal decompression via the transnasal approach followed by radiotherapy alone. Overall, no visual progression events were observed in patients who did not undergo optic canal decompression, whereas 4 visual progression events occurred in those who did (Figure 1B). The median visual PFS was not reached in the no decompression group; in the decompression group, median visual PFS was 164 months. Univariate Cox proportional hazards regression analysis for PFS and visual PFS is summarized in Table 7. For PFS, younger age (HR 0.928; 95% CI, 0.876-0.984; P = .012) was a significant predictor; WHO grade ≥2 was not estimable due to complete separation (both patients with WHO grade ≥2 experienced progression). Preoperative tumor embolization was not significantly associated with PFS (HR 0.765; 95% CI, 0.093-6.277; P = .803). For visual PFS, no variable reached statistical significance; WHO grade ≥2 was not estimable due to complete separation. Sex and optic canal decompression were not estimable for visual PFS owing to quasi-complete separation.
TABLE 5.
Visual Function Outcomes and Optic Canal Decompression
| Preoperative visual impairment | Optic canal decompression | n | Improvement of postop (4-6 mo) visual impairment | Visual acuity ≤ hand motion at last follow-up |
|---|---|---|---|---|
| None | Yes | 10 | Not applicable | 2 |
| None | No | 9 | Not applicable | 0 |
| Impaired | Yes | 10 | 7 | 2 |
| Impaired | No | 1 | 0 | 0 |
TABLE 6.
Details of Patients Whose Visual Function Improved After Surgery
| Case | Approach | Extent of resection | Radiation | Follow-up duration (mo) | Visual acuity ≤ hand motion at last follow-up |
|---|---|---|---|---|---|
| Case 1 | Transnasal | Biopsy (<10%) | Yes | 107 | No |
| Case 2 | Frontotemporal | Partial resection (10%-49%) | Yes | 137 | No |
| Case 3 | Frontotemporal | Partial resection (10%-49%) | Yes | 63 | Yes |
| Case 4 | Frontotemporal | Partial resection (50%-90%) | Yes | 177 | Yes |
| Case 5 | Orbitozygomatic | Partial resection (50%-90%) | No | 13 | No |
| Case 6 | Frontotemporal | Partial resection (50%-90%) | Yes | 176 | No |
| Case 7 | Frontotemporal | Subtotal resection (>90%) | No | 117 | No |
TABLE 7.
Univariate Cox Proportional Hazards Regression Analysis for Progression-Free Survival and Visual Progression-Free Survival
| Variable | HR | 95% CI | P value |
|---|---|---|---|
| PFS (9 events) | |||
| Age | 0.928 | 0.876-0.984 | .012 |
| Sex (female) | 1.636 | 0.199-13.448 | .647 |
| Tumor volume (cm3) | 0.996 | 0.968-1.024 | .757 |
| EOR (%) | 0.995 | 0.975-1.015 | .630 |
| WHO grade ≥2 | — | — | — |
| Preoperative visual impairment | 1.157 | 0.308-4.353 | .829 |
| Preoperative tumor embolization | 0.765 | 0.093-6.277 | .803 |
| Planned radiotherapy | 0.951 | 0.196-4.610 | .950 |
| Visual PFS (4 events) | |||
| Age | 0.978 | 0.896-1.068 | .623 |
| Sex (female) | — | — | — |
| Tumor volume (cm3) | 0.972 | 0.901-1.049 | .463 |
| EOR (%) | 0.977 | 0.941-1.013 | .209 |
| WHO grade ≥2 | — | — | — |
| Preoperative visual impairment | 0.561 | 0.046-6.902 | .651 |
| Optic canal decompression | — | — | — |
| Planned radiotherapy | 3.779 | 0.235-60.649 | .348 |
EOR, extent of resection; HR, hazard ratio; PFS, progression-free survival; WHO, World Health Organization.
WHO grade ≥2 was not estimable for PFS or visual PFS due to complete separation (all patients with WHO grade ≥2 experienced events; n = 2). Sex and optic canal decompression were not estimable for visual PFS due to quasi-complete separation (all events occurred within one category). Planned radiotherapy was defined as radiotherapy administered within 1 year of surgery in the absence of radiological tumor progression.
Representative Cases
Case 1
A 72-year-old man underwent resection of a CSM with large extracavernous component via the orbitozygomatic approach (EOR 85.9%) without optic canal decompression (Figure 2A). His symptoms of dizziness and gait instability improved. Pathology revealed WHO grade 1 meningioma. No adjuvant radiotherapy was administered. The patient remained progression-free with a KPS score of 100 at 81 months.
FIGURE 2.
Gadolinium-enhanced T1-weighted magnetic resonance imaging and T2-weighted imaging of A, case 1, B, case 2, C, case 3, and D, case 4.
Case 2
A 32-year-old asymptomatic woman presented with a tumor predominantly confined to the cavernous sinus and underwent biopsy and optic canal decompression via the transnasal approach (Figure 2B). Pathology revealed WHO grade 1 meningioma. Postoperative Gamma Knife radiosurgery resulted in tumor shrinkage, which was maintained over 81 months of follow-up. Final KPS score was 100.
Case 3
A 33-year-old woman with visual impairment underwent maximal safe resection of the extracavernous component via the frontotemporal approach (EOR 80.7%) with optic canal decompression. Despite initial improvement, repeated tumor progression required 4 surgeries and adjuvant IMRT (54 Gy/30 fractions) (Figure 2C). Almost 14 years after the initial surgery, her visual acuity had deteriorated to perception of hand motion (KPS 80).
Case 4
A 39-year-old woman presented with oculomotor nerve palsy and underwent biopsy and optic canal decompression via the frontotemporal approach. Pathology revealed WHO grade 2 meningioma. Despite Gamma Knife radiosurgery and multiple subsequent surgeries and radiotherapy sessions (Figure 2D), her functional status progressively declined. At 163 months of follow-up, her KPS score was 10, and she was transferred to hospice care.
DISCUSSION
Meningiomas are generally benign, and prognosis is favorable when gross total resection can be achieved.21 However, for those in which complete resection is challenging to achieve, such as CSM, clinical issues include recurrence and symptom progression due to growth of residual disease. Our cohort of patients with CSM who underwent surgery included those in whom visual acuity improved after a minimally invasive transnasal procedure consisting of biopsy with optic canal decompression, and in whom long-term tumor control was subsequently maintained with adjuvant radiotherapy. More complete resection may be possible with tumors with a larger extracavernous component, suggesting that the EOR itself may have limited impact on long-term visual outcomes. When the extracavernous component is small, a less invasive strategy—namely, endonasal biopsy with optic canal decompression—may effectively preserve visual function.
To our knowledge, detailed long-term visual trajectories and time-to-event analyses of visual deterioration after surgical management of CSM have not been well characterized. Given the small number of events in the present case series, the following observations should be considered exploratory. In our series, visual acuity in 4 patients ultimately deteriorated to perception of hand motion or worse, regardless of the presence or absence of preoperative visual impairment, and all had undergone optic canal decompression. Although the median visual PFS was not reached in patients who did not undergo optic canal decompression, this finding should be interpreted cautiously because of the limited number of events and substantial censoring. The median visual PFS was 164 months, indicating that severe visual decline may occur even after relatively prolonged periods of disease control. No patient who did not undergo optic canal decompression deteriorated to perception of hand motion or worse at final follow-up. This finding likely reflects confounding by indication, as optic canal decompression tends to be performed in patients with tumor involvement around the optic apparatus, who have a higher inherent risk of visual deterioration. Nevertheless, at least in the short term, visual improvement was frequently achieved in our cohort. Previous reports have also shown that endonasal optic canal decompression can improve visual function at 1 and 6 months postoperatively.22
Although all 4 patients with severe visual deterioration had received radiotherapy, this association likely reflects treatment selection bias rather than a causal effect, as durable tumor control was also observed after radiotherapy.
Attempts at radical intracavernous resection have been associated with a substantial risk of CN morbidity. Accordingly, the primary therapeutic goals in resection of CSM are preservation of neurological function and control of tumor growth. In many cases, maximal safe resection within an acceptable risk profile combined with radiotherapy constitutes the standard treatment strategy.15,17 By contrast, other studies have revisited the potential benefits of more aggressive intracavernous tumor debulking within safe limits. Recent reports have demonstrated that the combined transpetrosal approach enables safe and maximal tumor resection from the posterior aspect of the clinoid process.23,24
CN outcomes also merit consideration. In our cohort, visual function and trigeminal neuralgia showed substantially higher improvement rates than other CN deficits involving the cavernous sinus. This finding is consistent with the known difficulty of reversing established CN III-VI deficits and underscores that the primary surgical objective in CSM should be prevention of further neurological decline rather than restoration of existing deficits. The short-term visual preservation effect of optic canal decompression has been reported previously, and our findings are in agreement. Given the strong impact of visual deterioration on quality of life, optic canal decompression may represent a key technique for long-term visual preservation. The endonasal approach is particularly advantageous because it allows wide bilateral optic canal decompression without performing a craniotomy. In our cohort, despite residual intracavernous tumor, many patients achieved long-term disease control through appropriately timed reoperations and/or radiotherapy, suggesting that routine aggressive resection of the cavernous sinus component is not warranted in most patients. Skull base meningiomas, including CSMs, have been reported to grow more slowly than convexity meningiomas.25 In addition, CSMs harbor fewer macrophages and regulatory T cells associated with tumor growth than other meningioma subtypes.26 Differences in the tumor microenvironment may therefore contribute to the relatively indolent growth behavior of CSM. Furthermore, anterior and medial skull base meningiomas, including CSM, harbor mutations in the genes for tumor necrosis factor receptor–associated factor 7, Krüppel-like factor 4, v-akt murine thymoma viral oncogene homolog 1, and smoothened more frequently than convexity meningiomas, which more commonly have mutations in neurofibromin 2.27 These genetic alterations have been associated with greater genomic stability and a clinically less aggressive phenotype; such distinct biological behavior may be relevant to the natural history and treatment response of CSMs.
Limitations
This study is limited by its retrospective, single-center design and the small sample size of 30 patients, which limited statistical power and precluded multivariate analysis owing to insufficient events per variable. The cohort is inherently heterogeneous, combining primary and secondary CSMs, various WHO grades, multiple surgical approaches, and varying extents of resection; this heterogeneity reflects the clinical reality of this pathology but limits the generalizability of between-group comparisons. No formal power analysis was performed, given the exploratory nature of this case series. Comparisons between the radiotherapy and no radiotherapy groups are descriptive and confounded by treatment selection bias, as radiotherapy was preferentially administered to patients with more aggressive or progressive disease; a time-dependent treatment analysis would be required to assess the independent effects of radiotherapy. The observation that all visual deterioration events occurred in the optic canal decompression group is subject to confounding by indication and should not be interpreted as a causal relationship. Detailed longitudinal assessment of neurological symptoms was not consistently available unless severe deficits occurred. Treatment selection may also have been influenced by surgeon preference and temporal trends, such as the increasing adoption of endonasal approaches in more recent years.
CONCLUSION
In this case series, we described the visual and treatment outcomes of 30 patients with CSM at our institution. Our findings suggest the possibility of delayed visual deterioration despite prolonged disease control, although the small number of events limits definitive conclusions. Optic canal decompression may facilitate early visual improvement; however, comparisons between decompression and nondecompression groups are confounded by indication. Given the generally benign nature of CSM and the long survival of affected patients, treatment strategies should prioritize preservation of visual function and overall quality of life. Further studies with larger cohorts are needed to identify risk factors for tumor progression and visual deterioration.
Acknowledgments
The authors thank Edanz (https://jp.edanz.com/ac) for editing a draft of this manuscript. Author contributions: Conception and design: Hino, Tamura. Acquisition of data: Hino, Sogano, Karatsu, Sayanagi. Analysis and interpretation of data: Hino, Tamura. Drafting the manuscript: Hino. Critically revising the manuscript: Tamura, Ueda, Toda. Reviewed submitted version of manuscript: all authors. Statistical analysis: Hino. Study supervision: Tamura, Toda.
Contributor Information
Utaro Hino, Email: utaro526@gmail.com.
Junki Sogano, Email: jnk.sogano@gmail.com.
Kosuke Karatsu, Email: chilipep1221@gmail.com.
Taichi Sayanagi, Email: t_sayanagi@keio.jp.
Ryo Ueda, Email: ueda.ryo@gmail.com.
Masahiro Toda, Email: todam@keio.jp.
Funding
This study did not receive any funding or financial support.
Disclosures
The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
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