Thymoma--an important differential diagnosis of mediastinal tumours.

A 69-year-old man with slight dyspnoea underwent routine X-ray examination by his primary care physician. The X-ray and the CT showed a homogenous mass at the right side of the anterior mediastinum. The benignity and the origin of the tissue were still unknown. Therefore, we performed a CT-guided fine needle aspiration biopsy of the mediastinal mass. Histopathological examination finds out a spindle-cell or type A thymoma. Based on these findings we decide for a thoracoscopic resection of the thymoma. After the surgical intervention the patient was completely asymptomatic. In conclusion, because thymomas are prone to ectopic occurrence, they should be considered in the differential diagnosis of mediastinal tumors.