High-Grade Angiosarcoma Transformation in Schwannoma and SMARCB1 Mutation: A Case Report

Area of Science:

• Oncology
• Pathology
• Genetics

Background:

• Epithelioid angiosarcoma arising in a schwannoma is an extremely rare and aggressive cancer.
• This condition combines schwannoma's spindle cell features with angiosarcoma's epithelioid and vascular traits.
• Loss-of-function mutations in SMARCB1 are implicated in aggressive cancers.

Purpose of the Study:

• To report a case of high-grade epithelioid angiosarcoma arising in a schwannoma.
• To highlight diagnostic challenges and the role of molecular profiling.
• To discuss treatment strategies and prognostic biomarkers.

Main Methods:

• Case report of a 58-year-old male with slow-growing masses.
• Diagnostic workup included ultrasound, MRI, surgical resection, biopsy, PET scan, and Tempus molecular profiling.
• Treatment involved weekly paclitaxel, tazemetostat, and palliative radiation.

Main Results:

• Histopathology revealed high-grade epithelioid angiosarcoma arising in a schwannoma with positive margins.
• Molecular profiling identified SMARCB1 frameshift loss-of-function.
• The patient experienced symptomatic progression despite systemic therapy and palliative radiation.

Conclusions:

• Diagnosis of epithelioid angiosarcoma in schwannoma is challenging due to non-specific presentation.
• Histopathology, immunohistochemistry, and SMARCB1 mutation status are crucial for diagnosis and prognosis.
• Multimodal treatment including surgery, chemotherapy, and radiotherapy is recommended, with close monitoring for recurrence.