Surgical management and prognostic factors for primary intracranial myxoma: a single-institute experience with a systematic review

OBJECTIVE: Primary intracranial myxomas (PICMs) are extremely rare neoplasms, and their management and prognostic factors remain ambiguous. The authors aimed to elaborate the radiological features, evaluate the risk factors for progression-free survival (PFS), and propose a treatment protocol based on pooled data from cases treated at their institute and those found in the literature. METHODS: Clinical data from all cases of PICMs treated at the authors' institute and those cases reported in the English-language literature between 1987 and December 2017 were reviewed. The authors searched the Ovid MEDLINE, Embase, PubMed, and Cochrane databases using the keywords "myxoma" and "central nervous system," "intracranial," "cerebral," "skull base," "skull," or "brain." Previously published data were processed and used according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Risk factors in the pooled cohort were evaluated. RESULTS: Cases from the authors' institute included 21 males and 9 females, with a mean age of 35.7 ± 1.7 years. Gross-total resection (GTR) and non-GTR were achieved in 6 (20.0%) and 24 (80.0%) patients, respectively. After a mean follow-up of 86.7 ± 14.1 months, recurrence occurred in 6 (24%) patients, for a median PFS time of 85.2 months (range 36.0-136.0 months) and no deaths. In the literature between 1987 and 2017, 35 cases of PICM were identified in 14 males and 21 females with a mean age of 31.7 ± 3.2 years. GTR and non-GTR were achieved in 23 (65.7%) and 9 (25.7%) cases, respectively. After a mean follow-up of 25.8 ± 6.9 months (range 1.0-156.0 months), recurrence occurred in 4 (14.3%) patients, for a median PFS time of 11.0 months (range 3.0-36.0 months) and no deaths. Actuarial PFS rates at 1, 5, and 10 years were 93.0%, 80.6%, and 67.9%, respectively. A multivariate model demonstrated that GTR (HR 0.058, 95% CI 0.005-0.680, p = 0.023) was the only factor that favored PFS. CONCLUSIONS: PICMs are rare neoplasms with a slightly higher occurrence in males. GTR was the only favorable factor for PFS. Based on statistical results, GTR alone, if tolerable, is advocated as the optimal treatment for PICM. Nevertheless, conservative excision may be preferred to avoid damage to vital structures. PICMs have a tendency to recur within a few years of the initial surgery if resection is incomplete; therefore, close postoperative follow-up is mandatory. Future studies with larger cohorts are necessary to verify the study findings.Systematic review registration no.: CRD42018091517 (www.crd.york.ac.uk/prospero/).