Acquired Platythorax, or Anteroposterior Flattening of the Chest Wall, as a Late Complication of Cyclophosphamide Treatment for Childhood Acute Lymphoblastic Leukemia, Presenting in a Young Man with Respiratory Failure.

BACKGROUND Acquired platythorax, or flattening of the chest with a reduction in the anteroposterior (AP) diameter, is very rare and the prognosis depends on the degree of the deformity, respiratory function, and on any underlying disease. Drug-induced pulmonary fibrosis is associated with pulmonary hypoplasia. A case of acquired platythorax is presented in a young man previously treated with cyclophosphamide in childhood. CASE REPORT A 20-year-old man began to experience cough, chest pain, and mild exertional dyspnea. He was admitted to the hospital at 23 years of age with respiratory failure. Chest imaging showed pleural thickening and platythorax. He had been successfully treated for acute lymphoblastic leukemia (ALL), at 3 years of age, with chemotherapy that included a cumulative dose of cyclophosphamide of 15.6 g/m². His ALL relapsed six years later and he was the treated again with cyclophosphamide and underwent a second and complete remission. A clinical diagnosis of late-onset cyclophosphamide-induced lung disease with progressive platythorax was made on the basis of his clinical history and on imaging findings of the ratio of the AP to lateral chest wall diameter when compared with age-matched controls. Despite continued remission of his ALL, he died of progressive cardiopulmonary failure at 25 years of age. CONCLUSIONS This report described a rare case of acquired platythorax, or flattening of the chest, in a young adult. The use of the ratio of the chest wall AP diameter to lateral diameter may be used in the early detection of this rare chemotherapy-induced complication in children and adults.