[Mediastinal widening simulating relapse in a case of Hodgkin's disease].

The appearance of a mediastinal mass in a patient with Hodgkin's disease in remission frequently indicates recurrence. However, benign processes such as rebound hyperplasia of the thymus gland should be included in the differential diagnosis. The authors present a case in which an anterior mediastinal mass was revealed by a routine chest radiograph 3 months after completion of combined modality treatment with low-dose radiation and MOPP chemotherapy for cervical Hodgkin's disease, stage I, nodular sclerosis. As the patient was clinically well with no other laboratory evidence of disease, recurrence was considered unlikely. Benign thymic enlargement was strongly suspected on the basis of striking resolution of the mediastinal mass after treatment with a short course of oral prednisolone. Thymic rebound in our case occurred coincidentally with the restoration of normal immune functions after removal of the stress imposed by antineoplastic treatment. The patient has remained free of disease recurrence for more than 20 months after cessation of therapy. Awareness of the possible benign etiology of a mediastinal mass may avert a diagnostic surgical exploration and also unnecessary adjuvant therapy.