Thymic rebound following successful chemotherapy of B-lymphoma in an adolescent boy.

Four months after termination of successful chemotherapy for epipharyngeal B-non-Hodgkin lymphoma, an enlarging anterior mediastinal mass was discovered in a 15-year-old boy. There was no other suspicion of tumour recurrence. A simple thymic rebound was likely and a conservative management was chosen. Follow up for more than 12 months was uneventful. The frequency of thymic hyperplasia after termination of chemotherapy is discussed. It is a benign immunological rebound phenomenon and does not require operative intervention.