Needle tract implantation of thymoma after transthoracic needle biopsy.

A 73 year old woman was admitted to hospital because of an anterior mediastinal mass. For definite diagnosis, needle biopsy was performed under fluoroscopic observation. The histopathological diagnosis was thymoma and combination chemotherapy was given. The tumour almost completely disappeared and the patient was discharged. But the tumour recurred in the left anterior chest wall four months later. It is suggested that the thymoma tissue had been implanted in the needle tract.