Introduction
Albeit rare overall, emerging ALK-fusion myofibroblastic/infantile-fibrosarcoma-like spindled-to-ovoid-sarcomas with tyrosine-kinase RAS::MAPK pathway fusions1,2, are increasingly identified using next generation sequencing and other advanced molecular studies for diagnosis, prognosis, and targeted therapy. Crizotinib treatment ofALK gene mutation tumors, including carcinomas, lymphoma and neuroblastoma have been reported3. Experience with targeted therapy in ALK -fusion sarcomas has mostly included inflammatory myofibroblastic tumor (IMFT)4, yet treatment of emerging novel ALK -fusions has not previously been described in detail. Crizotinib, an ALK tyrosine-kinase inhibitor, is a first-line agent used forALK -mutations3. We demonstrate successful treatment of a pediatric unique ERC1-ALK fusion sarcoma interdigitating the right hand that avoided distal forearm amputation by use of neoadjuvant crizotinib.