Durable response to serial tyrosine kinase inhibitors (TKIs) in an adolescent with metastatic TFG-ROS1 fusion positive Inflammatory Myofibroblastic Tumor (IMT).

Here, we present the case of an adolescent with a rare metastatic Inflammatory myofibroblastic tumor (IMT) harboring a TFG-ROS1 fusion initially detected on tumor progression and retrospectively identified in the primary tumor after targeted RNA sequencing. The patient benefitted from sequential TKIs over a 5-year period with response to the third generation ALK/ROS inhibitor, lorlatinib leading to resection of the primary tumor. Detailed molecular analysis can identify targetable oncogenic kinase fusions that alters management in patients with unresectable disease and should be considered in all patients.