SHORT COMMUNICATION Anterior mediastinal mass in children following chemotherapy for malignant disease: thymic hyperplasia vs recurrence M. E. Aribal, MD, Professor* C. Canpolat, MD, Professoryz S. G. Berrak, MD, Assistant Professoryz and P. Berik, MD, Fellowyz *Radiology Department, Marmara University Hospital, Istanbul, Turkey; yDepartment of Pediatric Hematology and Oncology, Marmara University Hospital, Istanbul, Turkey Anterior mediastinal masses in children following chemotherapy for malignant disease often cause diagnostic problems. Differential diagnosis of thymic hyperplasia from re- currence frequently poses a challenge both for the radiologist and the physician. Thymic hyperplasia was seen in five patients, three with Hodgkin’s disease, one with Burkitt’s lymphoma and one with Wilms’ tumour, after chemotherapy. In one patient, thymic hyperplasia was proven by biopsy and the other four were followed. None of the masses in the anterior mediastinum showed difference in size or shape during fol- low-up. We recommend that such patients should be evaluated cautiously before plan- ning an invasive procedure. In patients who did not have an anterior mediastinal mass prior to chemotherapy, diagnosis of thymic hyperplasia should be stressed. Ó 2003 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. Thymic hyperplasia appearing as an anterior medias- tinal mass after treatment of malignant disease, gen- erally seen in younger patients, often causes a diagnostic problem both for the radiologist and the clinician. Differentiating thymic rebound from recurrent tumour may pose a challenge, especially in paediatric patients following chemotherapy. In adults, abnormal masses arising after treatment of cancer are highly suspicious, since they may be indicative of re- current disease or relapse. Mediastinal masses are mostly the result of metastatic lymph node involve- ment. Only rarely has thymic hyperplasia been ob- served to give rise to an anterior mediastinal mass after treatment of malignant neoplasms with chemo- therapy, and those that were reported are usually in patients with Hodgkin’s disease (HD) [1–3]. In this study, we present five paediatric patients, with different types of malignant neoplasms, who had oc- currence of an anterior mediastinal mass after suc- cessful treatment of their disease with chemotherapy. CASE REPORTS Case 1 A 2.5-year-old white boy presented complaining of abdominal pain and constipation. Biopsy specimen and work-up revealed a small non-cleaved cell KEY WORDS: thymic hyperplasia; computed tomography; anterior mediastinal mass. (Received 20 July 2001; received in revised form 17 April 2003; accepted 3 May 2003) Correspondence should be addressed to: M. Erkin Aribal, Eyu ¨p Pas xa sok 20/15, Feneryolu, 81030 Istanbul, Turkey. Tel: 90-216- 327-6954; Fax: 90-216-327-6956. E-mail address: earibal@marmara.edu.tr z Tel: 90-216-327-7470; Fax: 90-216-327-6956. 1078–8174/03/000139+07 $30.00/0 Ó 2003 The College of Radiographers. Published by Elsevier Ltd. All rights reserved. Radiography (2003) 9, 139–145 doi:10.1016/S1078-8174(03)00042-7