Navigating Management of Spindle Cell/Sclerosing Rhabdomyosarcoma With FUS::TFCP2 Fusion in the Era of Targeted Therapy

Spindle cell/sclerosing rhabdomyosarcoma (ssRMS) with FUS-TFCP2 translocation is a rare, aggressive RMS subtype often involving facial and pelvic bones and showing poor response to standard therapy. The FUS-TFCP2 fusion drives ALK gene activation and overexpression, suggesting ALK as a therapeutic target, though clinical use of ALK inhibitors remains limited in this context. We report a case of mandibular ssRMS with FUS-TFCP2 fusion treated with the third-generation ALK inhibitor Lorlatinib, resulting in a marked clinical response. We also review the potential utility of ALK-targeted therapies in managing FUS-TFCP2 fusion-positive ssRMS and support further exploration of ALK inhibition in this subset.