A child had a pulmonary plasma cell granuloma/fibrous histiocytoma that recurred after lobectomy in 1952 and required pneumonectomy in 1953, at which time it extended into the mediastinum at the pulmonary hilus. A metastatic nodule was removed from within the diaphragmatic musculature. The long-term favorable outcome suggests a good prognosis after adequate surgical therapy. The possible relationship of fibrous histiocytoma/plasma cell granuloma to modified measles is discussed.