title: Malignant thymoma in a nine-year-old boy presenting with pleuropericardial effusion.
mesh_terms: D002648:Child; D004452:Echocardiography; D006801:Humans; D008297:Male; D010490:Pericardial Effusion / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D010996:Pleural Effusion / Q000209:etiology* / Q000601:surgery; D013945:Thymoma / Q000150:complications* / Q000473:pathology / Q000601:surgery; D013950:Thymus Gland / Q000473:pathology; D013953:Thymus Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery