Soft Tissue Tumor with Kinase Fusion: An Emerging Sarcoma Entity.

Introduction: Here, we report the first case of a soft tissue tumor with a fusion.

Case Presentation: The patient was an 11-year-old female presenting with a 5 cm intramuscular mass in the lower leg. Microscopic examination revealed a mitotically active spindle cell lesion with monomorphic and moderately atypical cells growing in a patternless pattern with the presence of stromal and perivascular keloidal collagen with focal immunoreactivity for smooth muscle actin and S100; negative stains included cytokeratins, CD34, and caldesmon.

SFPQ-ABL1-positive B-cell precursor acute lymphoblastic leukemias.

In recent years, a subgroup of B-cell precursor acute lymphoblastic leukemia (BCP ALL) without an established abnormality ("B-other") has been shown to be characterized by rearrangements of ABL1, ABL2, CSF1R, or PDGFRB (a.k.a.