Vestibular schwannoma natural history

Vestibular schwannoma natural history

see also Vestibular schwannoma conservative treatment.

Spontaneous involution of acoustic tumors does occur. Long-term follow-up is necessary to determine this potential 1).

Three-dimensional volumetric assessment of VS provides a more sensitive measure of tumor growth when compared with linear diameter assessment. Through volumetric analysis, a study revealed that a significant proportion of VSs demonstrate growth during observation 2).

An extensive MEDLINE search was performed to cull studies on VS growth according to sequential imaging. The percentages of growing and regressing tumors and lesions requiring treatment during follow-up periods were calculated. Factors associated with differences among studies were identified. Twenty-six studies including 1340 patients met all inclusion criteria. The overall frequency of VS growth during a mean follow-up period of 38 months was 46% (95% confidence interval [CI] 43-48%) and that of regression was 8% (95% CI 6-10%). The mean annual tumor growth rate was 1.2 mm/year. Furthermore, the percentage of cases requiring treatment during follow up was 18% (95% CI 16-21%). According to results of a sensitivity analysis, evaluation by serial MR imaging (39%, 95% CI 35-43%) and a prospective study design (29%, 95% CI 21-37%) were associated with less frequent reported tumor growth.

Conclusions: Although their applicability may be limited to relatively elderly patients with small tumors, data revealing a limited frequency of VS enlargement and an infrequent necessity for eventual therapy should assist decision-making in the treatment of small VSs causing minimal symptoms 3)

Volumetric tumor measurements from 3,505 serial MRI studies were analyzed from unselected consecutive patients undergoing wait-and-scan management at three tertiary referral centers between 1998 and 2018. Volumetric tumor growth was defined as a change in volume ≥20%.

Among 952 patients undergoing observation, 622 experienced tumor growth with initial growth-free survival rates (95% CI) at 1, 3, and 5 years following diagnosis of 66% (63-69), 30% (27-34), and 20% (17-24). Among 405 patients who continued to be observed despite demonstrating initial growth, 210 experienced subsequent tumor growth with subsequent growth-free survival rates at 1, 3, and 5 years following initial growth of 77% (72-81), 37% (31-43), and 24% (18-31). Larger tumor volume at initial growth (HR 1.13, p=0.02) and increasing tumor growth rate (HR 1.31; p<0.001) were significantly associated with an increased likelihood of subsequent growth, whereas a longer duration of time between diagnosis and detection of initial growth was protective (HR 0.69; p<0.001).

While most vestibular schwannomas exhibit an overall propensity for volumetric growth following diagnosis, prior tumor growth does not perfectly predict future growth. Tumors can subsequently grow faster, slower, or demonstrate quiescence and stability. Larger tumor size and increasing tumor growth rate portend a higher likelihood of continued growth. These findings can inform timing of intervention: whether upfront at initial diagnosis, after detection of initial growth, or only after continued growth is observed 4).

Of the 1,818 consecutive patients, diagnosed with VS during the period from 1975 to 2005, 729 patients were allocated to observation by repetitive magnetic resonance imaging. At least two scans had been performed in 552 patients at the time of data analysis. Two hundred thirty patients had a tumor confined to the internal acoustic meatus, whereas 322 patients had a tumor with an extrameatal extension. Growth to extrameatal extension was the definition for growth in intrameatal tumors, whereas a largest diameter change of more than 2 mm was the criteria for growth/shrinkage of extrameatal tumors. The mean observation time was 3.6 years (range, 1-15 yr).

Seventeen percent of the intrameatal tumors grew, whereas significantly more of the extrameatal tumors displayed growth during the period (28.9%). Growth occurred within the first 5 years after diagnosis. No correlation could be demonstrated between tumor growth rate, sex, or age.

VS growth occurs within the first 5 years after diagnosis in a limited number of tumors, primarily in tumors with an extrameatal extension. They found no relation between tumor growth and sex or age. These findings justify primary observation of small tumors. A treatment strategy is proposed for this disease, focusing on the patient group allocated to observation 5).

The natural history of Vestibular Schwannomas (VS) is yet not totally known, but most of them have the tendency to slow growth, sometimes without any kind of symptoms during the individuals entire time. About 69% of diagnosed VS do not grow at all and 16% of these can even regress. Considering tumors that grow, about 70% have grown less than 2mm an year. Advanced radiological diagnosis, especially magnetic resonance imaging with gadolinium helps us diagnose small and less symptomatic tumors. Treatment of choice still is complete tumor resection. Surgical approaches have improved considerably and have helped preserve facial nerve function and hearing. Considering VSs natural history, there is a possibility for conservative treatment for these tumors, because their growth in the first year after diagnosis predicts tumor growth behavior in the next years. Surgery should be done in cases of tumor growth, patients desire or symptoms worsening. Moreover, in terms of postoperative sequelae, there is no difference between patients who underwent surgery immediately after diagnosis and those who underwent initial conservative treatment for these tumors 6).


Luetje CM. Spontaneous involution of acoustic tumors. Am J Otol. 2000 May;21(3):393-8. PubMed PMID: 10821554.

Lees KA, Tombers NM, Link MJ, Driscoll CL, Neff BA, Van Gompel JJ, Lane JI, Lohse CM, Carlson ML. Natural History of Sporadic Vestibular Schwannoma: A Volumetric Study of Tumor Growth. Otolaryngol Head Neck Surg. 2018 Sep;159(3):535-542. doi: 10.1177/0194599818770413. Epub 2018 Apr 24. PMID: 29685084.

Yoshimoto Y. Systematic review of the natural history of vestibular schwannoma. J Neurosurg. 2005 Jul;103(1):59-63. doi: 10.3171/jns.2005.103.1.0059. PMID: 16121974.

Marinelli JP, Schnurman Z, Killeen DE, Nassiri AM, Hunter JB, Lees KA, Lohse CM, Roland JT, Golfinos JG, Kondziolka D, Link MJ, Carlson ML. Long-term Natural History and Patterns of Sporadic Vestibular Schwannoma Growth: A Multi-institutional Volumetric Analysis of 952 Patients. Neuro Oncol. 2021 Dec 29:noab303. doi: 10.1093/neuonc/noab303. Epub ahead of print. PMID: 34964894.

Stangerup SE, Caye-Thomasen P, Tos M, Thomsen J. The natural history of vestibular schwannoma. Otol Neurotol. 2006 Jun;27(4):547-52. doi: 10.1097/01.mao.0000217356.73463.e7. PMID: 16791048.

Oliveira Penido N, Tangerina RP, Macoto Kosugi E, Cesário de Abreu CE, Brandão Vasco M. Vestibular Schwannoma: spontaneous tumor involution. Braz J Otorhinolaryngol. 2007 Nov-Dec;73(6):867-871. doi: 10.1016/S1808-8694(15)31189-7. PubMed PMID: 18278239.

Trepanation, Trephining and Craniotomy History and Stories

Trepanation, Trephining and Craniotomy History and Stories

by José M González-Darder (Author)

List Price: $149.99


This book takes readers on a journey around the world and through time, accompanied by a modern neurosurgeon who reviews historical techniques and instruments used for cranial opening. The author draws on original medical and surgical books to provide a comprehensive history of these techniques and tools.

To complement the general overview and offer readers a more ‘hands-on’ sense of context and atmosphere, extensive historical references, stories, media news, and illustrative cases have been included for each historical and geographical scenario. In addition, original illustrations and plates of these archaic instruments and techniques are supplied.

Neurosurgical surgeons, nurses, technicians, medical historiographers, paleo-pathologists and researchers interested in surgical techniques for cranial opening will find the volume a valuable guide, intended to increase the historical and cultural awareness of this core topic in neurological surgery.

Pituitary Adenoma Natural History

Pituitary Adenoma Natural History

Pituitary adenomas (PAs) are often detected as incidentalfindings. However, the natural history remains unclear. The objective of a study of Hwang et al., was to evaluate the natural history and growth pattern of untreated PAs.

Between 2003 and 2014, 59 PAs were managed with clinico-radiological follow up for longer than 12 months without any kind of therapeutic interventionTumor volumes were calculated at initial and last follow-up visit, and tumor growth during the observation period was determined. Data were analyzed according to clinical and imaging characteristics.

The mean initial and last tumor volume and diameter were 1.83±2.97 mL and 13.77±6.45 mm, 2.85±4.47 mL and 15.75±8.08 mm, respectively. The mean annual tumor growth rate was 0.33±0.68 mL/year during a mean observation period of 46.8±32.1 months. Sixteen (27%) PAs showed tumor growth. The initial tumor size (HR, 1.140; 95% confidence interval, 1.003-1.295; p=0.045) was the independent predictive factor that determined the tumor growth. Six patients (11%) of 56 conservatively managed non-symptomatic PAs underwent resection for aggravating visual symptoms with mean interval of 34.5 months from diagnosis. By Cox regression analysis, PAs of last longest diameter over 21.75 mm were a significant prognostic factor for eventual treatment.

The initial tumor size of PAs was independently associated with the tumor growth. Six patients (11%) of conservatively managed PAs were likely to be treated eventually. PAs of last follow-up longest diameter over 21.75 mm were a significant prognostic factor for treatment. Further studies with a large series are required to determine treatment strategy 1).

Despite the relatively high prevalence of pituitary incidentalomas (PIs)/nonfunctioning pituitary adenomas (NFPAs), the evidence on the natural history of these entities is scarce and of low quality. PIs/NFPAs seem to have fairly rare complications that may be more common when lesions are large (>10 mm) and solid 2).

The ‘watch and wait’ policy seems reasonable for microadenomas but is probably not a safe approach for macroadenomas, which appear to have a significant growth potential; in these cases, given the lack of established medical treatment, the decision for surgical intervention should balance the presence of significant comorbidities and the anaesthetic/peri-operative risks at presentation against the probability of tumour enlargement and its consequences, as well as the possible loss of advantages associated with early operation 3).



Hwang K, Kwon T, Park J, Joo JD, Han JH, Oh CW, Kim CY. Growth Pattern and Prognostic Factors of Untreated Nonfunctioning Pituitary Adenomas. J Korean Neurosurg Soc. 2019 Mar;62(2):256-262. doi: 10.3340/jkns.2018.0153. Epub 2019 Feb 27. PubMed PMID: 30840981.

Fernández-Balsells MM, Murad MH, Barwise A, Gallegos-Orozco JF, Paul A, Lane MA, Lampropulos JF, Natividad I, Perestelo-Pérez L, Ponce de León-Lovatón PG, Erwin PJ, Carey J, Montori VM. Natural history of nonfunctioning pituitary adenomas and incidentalomas: a systematic review and metaanalysis. J Clin Endocrinol Metab. 2011 Apr;96(4):905-12. doi: 10.1210/jc.2010-1054. Review. PubMed PMID: 21474687.

Karavitaki N, Collison K, Halliday J, Byrne JV, Price P, Cudlip S, Wass JA. What is the natural history of nonoperated nonfunctioning pituitary adenomas? Clin Endocrinol (Oxf). 2007 Dec;67(6):938-43. Epub 2007 Aug 13. PubMed PMID: 17692109.
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