Résumé
Teratomas mediastinais representam 8 a 13 por cento dos tumores nesta região. Uma paciente de 27 anos apresentou-se com dor torácica e dispnéia de evolução arrastada. O radiograma de tórax revelou opacidade quase total do hemitórax direito, levando à suspeita de derrame pleural. A tomografia de tórax evidenciou coleção pleural heterogênea, de contornos regulares (10,1 x 11,7 cm), nos dois terços inferiores do hemitórax direito, sem envolvimento de estruturas adjacentes. Na toracotomia exploradora, pela hipótese de teratoma cístico benigno do mediastino, realizou-se ressecção total da lesão, com boa evolução pós-operatória. A apresentação atípica e grande crescimento do tumor dificultaram o diagnóstico pré-operatório.
Teratomas account for 8-13 percent of all mediastinal tumors. A 27-year-old patient presented with chest pain and dyspnea of prolonged evolution. A chest X-ray revealed near total opacification of the right hemithorax. On a tomography scan of the chest, a collection of heterogeneous fluid, with irregular borders and 10.1 x 11.7 cm in size, was seen in the pleura of the lower two-thirds of the right hemithorax but was not encroaching on any of the adjacent structures. Based on the hypothesis that these findings represented a benign mediastinal teratoma, an exploratory thoracotomy was performed, during which such a teratoma was found and completely excised. The post-operative evolution was favorable. The atypical presentation and considerable growth of the tumor hindered the pre-operative diagnosis.