Mediastinal Hodgkin's disease and thymic cysts.

2 cases of nodular sclerosing Hodgkin's disease with apparent mediastinal recurrence following mantle irradiation are described. In both cases the abnormal mass was found at thoracotomy to be a benign thymic cyst. The possible aetiology of thymic cysts in this context and the importance of obtaining repeat biopsies in cases of suspected relapse are discussed.