Management of growing vestibular schwannomas

Abstract

Conservative management of small vestibular schwannomas is frequently proposed as most tumours do not grow. Anyway, tumour growth is reported in 30-40 % of the cases, so that surgery is consequently generally proposed. We primarily observed 161 patients affected by unilateral vestibular schwannomas. All patients were examined by means of gadolinium-enhanced magnetic resonance imaging scans. Tumour growth was recorded in 58 cases (35.8 %) and these subjects set up the group of study. Twenty-two (37.9 %) patients were surgically treated; tumour was always completely removed, all patients had normal facial function after surgery and only one patient suffered from a major complication (cerebellar haematoma). Fourteen patients (24.1 %) were submitted to radiotherapy, while one patient was lost at follow-up and another one died because of other medical reasons. Finally, 20 (34.5 %) subjects continued to be observed for different reasons. The mean follow-up period after identification of growth was 6.1 years. Nine tumours continued to grow, nine tumours stopped growing, one tumour grew and then regressed in size and one tumour decreased. Sixty percent of patients with useful hearing at diagnosis preserved it during the entire observation period. In conclusion, most of VS do not grow; in case of tumour growth, a surgical procedure may be suggested and the outcomes are not negatively influenced by the delay of the procedure. But in some cases, patients can still follow the "wait and scan" policy. In fact, only less than half of the growing tumours continued to grow. Moreover, most of the patients continued to retain a useful hearing.

Natural History of Growing Sporadic Vestibular Schwannomas During Observation: An International Multi-Institutional Study

“…In this way, modern patient counseling and the observation treatment paradigm presuppose a saltatory growth pattern of sporadic VS. Substantiating this, large population-based data demonstrate that 75% of IAC tumors and almost 60% of CPA tumors exhibit no evidence of tumor growth after 10 years of observation (15). Moreover, it has been recently demonstrated in a volumetric analysis of 85 patients, as well as previously observed in a subgroup of 20 patients undergoing observation who demonstrated growth but could not undergo treatment, that not all patients who previously demonstrated tumor growth experience continued growth over time (16,17). Taken together, the primary conclusion of the current study—that growth detected during observation does not necessarily portend future growth—should not be overly surprising.…”

Management of Vestibular Schwannoma with Normal Hearing

“…Two intrameatal cases showed no growth after initial growth. As shown by some authors, a mixed growth pattern could be indicative to proceed with further W&S [Ferri et al, 2012;Patnaik et al, 2015].…”

Screening for vestibular schwannoma in the context of an ageing population

“…While most papers considered an increase in extra-canalicular diameter as growth, 17,19,20,22–29,31,32,35,40 some studies used an increase in tumour volume or volume doubling time. 34 Even when diameter was considered, some papers defined growth as 2 mm or more per year, 17,19,22,23,25,29,33,36 while others defined it as 1 mm or more. 20,27,31,37 The time interval used to measure growth was also variable.…”

“…20,27,31,37 The time interval used to measure growth was also variable. While most considered growth per annum, 19,20,22,23,25,27,29,31,33,36,37 others considered the growth between two successive scans, 17,26,32,38,39 although imaging is not always conducted at one-year intervals.…”

“…The average tumour size at diagnosis varied from 5.1 mm 20 to 20.1 mm. 26 No average value was reported in five articles; 22,29,35,36,38 two articles 30,33 included intra-canalicular tumours only, two articles 23,39 included intra-canalicular tumours and up to 2 cm of extra-canalicular tumours, while one article 34 considered tumour volume. We calculated the weighted average diameter of tumours at diagnosis as 9.32 mm.…”