Inflammatory myofibroblastic tumor (IMT) is a neoplastic proliferation of myofibroblastic/fibroblastic cells with a variable admixture of inflammatory cells. It primarily affects soft tissue and viscera of children and young adults. IMT occurring in bone is extremely rare. Approximately 50% of IMTs carry a clonal rearrangement of the anaplastic lymphoma kinase (ALK) gene, while other receptor tyrosine kinase gene rearrangements have been seen in a small subset of IMT. Herein, we report the first case of IMT which harbors an ALK gene amplification rather than a rearrangement thus resulting in overexpression of the protein, arising from the femur of a 24-year-old man. Our case provides a novel pathogenesis for IMT. An overview of cytogenetic abnormalities of IMT is also integrated into this report. READ ARTICLE
Pathology - Research and Practice DOI:10.1016/j.prp.2019.152535
Authors: Kai Wang, Rongjun Guo, Gene P. Siegal, Shi Wei
Introduction: Half of inflammatory myofibroblastic tumors (IMTs) regardless of anatomic location harbor anaplastic lymphoma kinase gene (ALK) rearrangements and overexpress anaplastic lymphoma kinase protein. The wide application of next-generation sequencing and the clinical benefit to tyrosine kinase inhibitors have opened new opportunities for investigation of ALK-negative IMTs. Conclusions: By using a battery of complementary molecular techniques, we have shown that all the thoracic IMTs harbored a tyrosine kinase abnormality, with 30% involving a kinase gene other than ALK, including ROS1, NTRK3, and RET gene fusions. We have also described for the first time ALKATI-induced ALK oncogenic activation in IMTs. READ ARTICLE
Journal of Thoracic Oncology DOI:10.1016/j.jtho.2018.12.003
Authors: Jason C. Chang, Lei Zhang, Alexander E. Drilon, Ping Chi, Rita Alaggio, Laetitia Borsu, Ryma Benayed, William D. Travis, Marc Ladanyi, Cristina R. Antonescu