Thymoma and lupus: two cases and a literature review.

Introduction. - Thymoma is a tumour originating in the epithelial cells of the thymus, associated with several immunologic disorders. The association of thymoma with systemic lupus erythematosus has rarely been described. We report two cases of this association. Exegesis. - Description of two cases and a review of the literature. Mr T: was 41 years old when the diagnosis of thymoma and lupus was made. The thymectomy did not influence the evolution of his lupus. Mrs G. had been treated because of a lupus for 8 years prior to developing a thymoma. One year later she presented with erythroblastopenia, which was only sensitive to cyclosporin. Conclusion. - The association between lupus and thymoma has been reported in 36 cases in the literature. Thymoma is benign in 59% of the cases. The clinical presentation of lupus is nonspecific except for age, median 48 years, and sex ratio, 4:3. The clinical outcome of the lupus is not influenced by the thymectomy. Thymoma may precede lupus with a delay of several years or it may be diagnosed concurrently or several years later. This association is not accidental, though the pathogenic link between these conditions remains unknown. One could suppose that the decrease of the thymic function in the course of thymoma could enhance the expression of autoreactive T lymphocytes as well as the activation of B cells. Patients should be followed after thymectomy because autoimmune diseases, particularly lupus, may develop belatedly. On the other hand, thymoma may be suspected mainly when lupus occurs in patients around 50 years of age. (C) 2001 Editions scientifiques et medicales Elsevier SAS.