[Mediastinal large B-cell lymphoma associated with systemic sclerosis].

Malignant lymphoma (ML) is frequently associated with several forms of collagen diseases such as Sjören syndrome, systemic lupus erythematodes, and rheumatoid arthritis. However, the occurrence of ML in systemic sclerosis (SSc) patients has rarely been reported. Here we report an SSc patient who developed mediastinal (thymic) large B-cell lymphoma (MLBCL). A 31-year-old woman was diagnosed as having SSc in August 2007. The patient was treated with low-dose prednisolone (10 mg/day) without any effect. One year after the diagnosis, chest computed tomography-scan demonstrated thymic tumor in the anterior mediastinum. Thymectomy was performed, and a pathohistological diagnosis of MLBCL was established. Immunohistochemical analysis demonstrated that the tumor cells were positive for CD45 and CD20, but negative for CD30 and EBV-encoded RNA. The patient was treated with 6 courses of CHOP regimen, resulting in complete remission of lymphoma. This report describes the first SSc patient associated with MLBCL. SSc patients occasionally develop ML after a relatively short interval. Our case suggests that intensive monitoring for the development of ML is needed in newly diagnosed SSc patients.