Complete remission following icotinib administration in an advanced ectopic thymic carcinoma patient harbouring the EGFR exon 19 deletion.

Background: Ectopic thymic carcinoma (TC) is an extremely rare disease with a poor prognosis. The main treatment for early TC is surgery, although an effective treatment for advanced TC is lacking. Methods: We present the case of a 61-year-old man with advanced posterior mediastinum thymic squamous cell carcinoma. Amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR) analysis was used to investigate the molecular and mutational characteristics of this tumour. Results: After chemotherapy and radiotherapy, the tumour showed disease progression. Immunohistochemistry revealed that the tumour was positive for CD117 (specific for primary TC), CK19, CD56 and Ki67. ARMS-PCR analysis revealed an EGFR exon 19 deletion in the patient. The patient subsequently received icotinib treatment and achieved complete remission for 3 years. Conclusions: This case report suggests that tyrosine kinase inhibitors are a potential treatment strategy for patients with TC harbouring EGFR alterations. [ABSTRACT FROM AUTHOR]