Abstract: Objective To investigate the clinical characteristics of systemic lupus erythematosus (SLE) with thymoma. Methods The clinical manifestations, laboratory tests, treatment and prognosis of SLE with thymoma from 1984 to 2015 in Peking Union Medical College Hospital were retrospectively reviewed. And comparison of cases in our study and in the literature was made. Results 11 cases of SLE patients complicated with thymoma were collected. The prevalence of thymoma in the total SLE patients was 1.55‰ and the prevalence of SLE in the total thymoma patients was 1.07% during the same period. 10 were female and 1 was man. The mean ages of the onset and diagnosis of SLE were 25.5 and 26.4 years old respectively. The mean age of thymoma was 28.5 years old. The average disease course from SLE to thymoma was 2.1 years old. The mean SLEDAI at the diagnosis of thymoma complicated with SLE was 3.6. 5 patients were performed thymectomy and 1 patient was given radiotherapy. According to the WHO classifications of thymoma, 2 cases were type A, 1 case was type AB, and 1 case was type C. 8 patients were followed up for 3 to 92 months, including 6 patients SLE stable, 1 patient SLE flare and 1 patient died of tumor metastasis. Compared with cases in the literature, our patients were younger and the rate of thymectomy was lower. Conclusions The coincidence of thymoma and SLE was not rare. Thymoma was concealed and could be involved in the pathogenesis of SLE. Thymectomy might contribute to the remission of SLE, which should arise the attention of clinicians.

Key words: lupus,systemic erythematosus, thymoma, thymectomy