Treatment and Clinical Outcome of a Patient With Spindle Cell Rhabdomyosarcoma Harboring MEIS1-FOXO1 Gene Fusion.

Fusion-driven extraosseous spindle cell rhabdomyosarcoma (SRMS) is a rare and recently recognized subcategory of rhabdomyosarcoma, with limited data on optimal management and clinical outcomes. We present the clinical course and long-term outcome of a unique case of SRMS harboring a novel gene fusion diagnosed in a 40-year-old female. The case was successfully managed with a treatment regimen including surgery, radiation, and chemotherapy following a low-risk rhabdomyosarcoma paradigm. This report highlights the importance of molecular diagnostics in identifying rare gene fusions in SRMS and may help guide the management of future patients.