Thymomas are rare in children. Most of them are asymptomatic and found incidentally on chest radiographs. In literature there are very few number of deaths reported due to the compressional effect of a Thymoma on the lungs. We present a case of a 14 year old girl, who died suddenly following an acute onset chest pain and dyspnoea. The autopsy revealed a mediastinal mass which encroached upon and compressed the Lungs causing respiratory failure and death. Further, Histopathological examination revealed the mass to be a Thymoma B1 (WHO classification). 

Keywords: Thymoma; Sudden death; Mediastinal mass; Respiratory failure.