Systematic Review of Endolymphatic Sac Tumor Treatment and Outcomes.

Objective: Endolymphatic sac tumors are rare neoplasms originating in the endolymphatic sac. Current literature is limited to case reports and small case series. The objective of this study was to systematically review the literature to better describe clinical presentation, treatment options, and outcomes in endolymphatic sac tumors.

Data Source: PubMed, Embase, and Cochrane Library.

Review Methods: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines describing human endolymphatic sac tumors. Risk of bias was assessed using a validated critical appraisal checklist for case series. Studies without inclusion of individual patient characteristics, corresponding treatments, and outcomes were excluded. Heterogeneity of data precluded meta-analysis.

Results: A total of 82 studies met inclusion criteria, and 253 discrete tumors were analyzed. A total of 23.4% of patients had von Hippel-Lindau disease. Von Hippel-Lindau-associated tumors affected females to males in a 2.4:1 ratio. Patients with von Hippel-Lindau disease displayed earlier average age at diagnosis compared to the sporadic cohort. Surgery was the primary treatment modality and was performed in 88.9% of cases. Adjuvant radiation therapy was employed in 18.7% of cases; 16.2% cases recurred, and 10.6% had progression of residual disease after treatment. Mean time to recurrence or progression was 53.1 ± 52.4 months with a range of 3 to 240 months.

Conclusion: Endolymphatic sac tumors require a high degree of suspicion for early diagnosis. Complete resection is the standard of care. No strong evidence supports routine use of adjuvant radiation therapy. Given the high rate of recurrence and wide-ranging time to recurrence, long-term follow-up is necessary.