[Traumatic pulmonary pseudocyst]

Traumatic pulmonary pseudocyst is an unusual complication that appears after a closed thoracic trauma. It is produced as a consequence of outburst and shear forces released by the impact on the elastic thoracic wall. We present a 14-year-old boy who, after a motorcycle crash, presented a traumatic pulmonary pseudocyst, isolated on the right hemithorax. The patient's evolution was good. The antecedent of trauma, together with radiological examination and the tendency toward spontaneous resolution, suggested the diagnosis as well as the advisability of a conservative approach in most pediatric cases. Recognition of this unusual disorder would help to avoid unnecessary diagnostic and therapeutic procedures.