Thymic enlargement following chemotherapy

Atrophy of the thymus during periods of stress is a well-recognised phenomenon in children. Thymic hyperplasia following the termination of a stressful period has been noted after recovery from burns (Gelfand & Goldman, 1972), after cessation of oral steroid treatment (Caffey & Sibley, 1960), and following successful surgery for transposition of the great vessels (Rizk et al, 1972). Cohen et al (1980) reported rebound thymic enlargement noted on the conventional PA chest radiographs of seven patients under ten years of age following courses of chemotherapy. The case presented below is of a 13-year-pld boy who received chemotherapy for a Ewing's sarcoma. Though conventional PA chest X rays were normal, thymic enlargement following chemotherapy was noted on computed tomography. A thirteen-year-old boy presented in February 1982 following several years of an aching pain in the right lower humerus. Surgical exploration of the upper arm demonstrated a Ewing's sarcoma. Using shrinking fields a course of radiotherapy sparing the growth plate was carried out during March and April 1982. This was followed by a course of chemotherapy. A regime of vincristine 1.5 mg/m2, Adriamycin 1 mg/m2 and cyclophosphamide 500 mg/m2 (VAC) was alternated with vincristine 1.5 mg/m2 and Adriamycin 60 mg/m2 (VA). A total of five courses was given between April 1982 and March 1983, at which time treatment was terminated. PA chest X rays were normal on presentation in April 1982 and have remained normal throughout his followup.