Rapid Response to Lenvatinib and Disease Flare After Discontinuation in a Patient With Thymic Carcinoma Harboring KIT Exon 11 Mutation: A Case Report oleh Masahiro Torasawa, MD, Tatsuya Yoshida, MD, PhD, Kouya Shiraishi, PhD, Naoko Goto, BS, Toshihide Ueno, PhD, Hitoshi Ichikawa, MD, PhD, Shigehiro Yagishita, MD, PhD, Shinji Kohsaka, MD, PhD, Yasushi Goto, MD, PhD, Yasushi Yatabe, MD, PhD, Akinobu Hamada, PhD, Hiroyuki Mano, MD, PhD, Yuichiro Ohe, MD, PhD