The First Reported Case of Neurotrophic Tyrosine Receptor Kinase Fusion-Positive Thymoma Treated Successfully With Entrectinib.

We present the first reported case of stage 4 thymoma with pleural metastases that was found to be driven by the neurotrophic tyrosine receptor kinase (NTRK)-fusion gene. The patient was started on chemotherapy but it was discontinued due to intolerable side effects. Alternative options in such patients with rare diseases are limited; in fact, many concerns exist regarding the safety and efficacy of newly approved agents for the treatment of advanced thymomas, such as pembrolizumab and sunitinib.