Ectopic thymoma: report of 2 cases and review of the literature.

In this report, we present two cases of ectopic thymoma, aiming to explore the clinicopathologic features, diagnosis, and differential diagnosis of ectopic thymoma. Case 1 was a female 56-years-old. For 6 months' time, there was no obvious cause of cough, expectoration, chest tightness, or asthma with chest pain. PET-CT showed a right middle lung and lower lung mass with increased FDG metabolism. Postoperative pathology was diagnosed as right middle and lower lung ectopic thymoma, type B2, invading the chest wall. Case 2 was a male of 54-years-old. By physical examination the right chest cavity had a mass present for 1 week and he was admitted to hospital. Postoperative pathology was diagnosed as right thoracic ectopic thymoma, type AB. No recurrence has been found to in the follow-up of these two patients. In conclusion, ectopic thymoma occurs outside the anterior mediastinum. It is rare, the clinical symptoms are not typical, and pre-operative diagnosis is difficult. It is easily misdiagnosed as other diseases. Surgical treatment is the best method. According to the pathologic type and invasion of the tumor, radiotherapy may be considered.