KIT is a growth factor receptor of the tyrosine kinase subclass III family, normally expressed in a variety of human tissues. Somatic mutations of KIT are only identified in ~ 4% of thymic carcinoma, but KIT protein overexpression has been observed in up to 88% of cases. Valine at amino acid position 560 (V560) is located in exon 11 within the juxtamembrane domain of KIT, and an in-frame deletion of V560 results in an activating mutation. A case report has described a patient with thymic carcinoma harboring KIT V560del who had a partial response to imatinib. In another case, patient who has kit mutation in his thymic carcinoma achieved 27 moths of disease control with imatinib followed by sunitinib. Results should be interpreted in conjunction with other laboratory and clinical findings.