Abstract
Background: A nine months female child presented with dyspnea was diagnosed by third author applying echocardi-ography who discovered a large thymic cyst. The diagnosis was confirmed by CT scan; the patient was operated on by the first author applying median sternotomy with smooth post operative recovery and complete absence of symptoms.
Aim of Study: We intended to report this rare case world-wide so that to throw light on every case with mediastinal cyst to include it in the differential diagnosis, and to be kept in mind always during investigating such a case.