Dyspnea as a clinical manifestation in primary retroperitoneal teratoma

The retroperitoneum is an unusual location for a teratoma in adults. We report a case of retroperitoneal teratoma with clinical manifestation of dyspnea and chest discomfort. Chest radiograph showed elevated left hemidiaphragm. Ultrasonography (US) showed a hypoechoic tumor in the left subphrenic area. Computed tomography (CT) revealed a hypodense tumor in the left subphrenic area. Endoscopic ultrasound-guided fine-needle aspiration of the tumor suggested a diagnosis of liposarcoma. Magnetic resonance imaging (MRI) showed a tumor in the left subphrenic area that was isointense to the spleen on T1-weighted images and hyperintense on T2-weighted images. No typical imaging characters of teratoma such as fat, fat-fluid level, calcification, hair, or Rokitansky bodies were depicted on US, CT, or MRI in our case. The thoracic symptoms completely disappeared after surgical removal of the tumor.