Epithelioid angiosarcoma arising from Schwannoma: report of a rare case and potential of circulating tumor DNA as a useful biomarker

Abstract

Epithelioid angiosarcoma arising from Schwannoma (EASS) is an exceptionally rare and aggressive malignant neoplasm with a poor prognosis. To date, only 22 cases have been reported in the literature, and its risk factors, etiology, and pathogenesis remain poorly understood. There is no established consensus for optimal management or surveillance strategies. These tumors may present as an asymptomatic or symptomatic mass, with most diagnoses being unexpected. Given the rarity and therapeutic challenges of EASS, we present a 58-year-old man diagnosed with EASS, highlighting the potential role of next generation sequencing (NGS) in identifying therapeutic targets and the use of circulating tumor DNA (ctDNA) as a potential tumor burden biomarker. Tumor-informed ctDNA was elevated to 30.49 at the time of diagnosis and increased to 213.90 after presence of metastasis. This case is the first documented instance of a SMARCB1 mutation in EASS, suggesting a potential therapeutic target. Further research is needed to better understand the etiology, pathogenesis, and optimal management strategies for EASS, including the role of targeted therapies based on NGS findings and the utility of ctDNA as a monitoring tool. Overall, the rarity and aggressive nature of EASS, a comprehensive metastatic workup, including cross-sectional imaging, is crucial for staging and management.