Synovial Sarcoma of the Nerve—Clinical and Pathological Features: Case Series and Systematic Review

Abstract

BACKGROUND Synovial sarcoma of the nerve is a rare entity with several cases and case series reported in the literature. Despite an improved understanding of the biology, the clinical course is difficult to predict. OBJECTIVE To compile a series of patients with synovial sarcoma of the peripheral nerve (SSPN) and assess clinical and pathological factors and their contribution to survival and recurrence. METHODS Cases from 2 institutions collected in patients undergoing surgical intervention for SSPN. Systematic review including PubMed and Scopus databases were searched for related articles published from 1970 to December 2018. Eligibility criteria: (1) case reports or case series reporting on SSPN, (2) clinical course and/or pathological features of the tumor reported, and (3) articles published in English. RESULTS From patients treated at our institutions (13) the average follow-up period was 3.2 yr. Tumor recurrence was seen in 4 cases and death in 3. Systematic review of the literature yielded 44 additional cases with an average follow-up period of 3.6 yr. From pooled data, there were 10 recurrences and 7 deaths (20% and 14%, respectively). Adjuvant treatment used in 62.5% of cases. Immunohistochemical markers used in diagnosis varied widely; the most common are the following: Epithelial membrane antigen (EMA), cytokeratin, vimentin, cluster of differentiation (CD34), and transducin-like enhancer of split 1 (TLE1). Statistical analysis illustrated tumor size and use of chemotherapy to be negative predictors of survival. No other factors, clinically or from pathologist review, were correlated with recurrence or survival. CONCLUSION By combining cases from our institution with historical data and performing statistical analysis we show correlation between tumor size and death.