KIAA1549-BRAF Gene Fusion Spindle Cell Sarcoma With Infantile Fibrosarcoma-Like Pattern in a Pediatric Patient: A Case Report.

Spindle cell sarcoma with fusion is a type of childhood sarcoma that closely resembles infantile fibrosarcoma by morphologic criteria and harbors molecular alteration other than the fusion gene. This neoplasm was diagnostically challenging without molecular tests, including next-generation sequencing. The discovery of translocation in this tumor contributes to the promise of the clinical implication of selecting new therapeutic options for the treatment of progressive diseases that are refractory to conventional chemotherapy. Here we present the case of a three-year-old girl who was diagnosed with spindle cell sarcoma with fusion gene and had a favorable outcome three years after surgery.