Two malignant tumours in the anterior mediastinum positive for CD5.

To our knowledge, the simultaneous involvement of the anterior mediastinum by a thymic carcinoma and a B-cell chronic lymphocytic leukaemia has not been reported previously. The authors describe the case of a 62-year-old man, suffering from severe bronchitis. Chest x-ray and CT scan showed a mediastinal tumour, resected short-time after diagnosis. First, standard based histological examination revealed a thymic carcinoma admixed by a dense lymphatic infiltrate. Additional immunohistochemical staining for CD5-labelled epithelial thymic carcinoma cells as well as neoplastic B cells and led in combination with blood tests to confirm the diagnosis of the composite occurrence of a thymic carcinoma and a B-cell chronic lymphocytic leukaemia.