A floating ball: a pathognomonic sign of ovarian cystic teratoma.

A 47-year-old woman with regular menstrual cycle had no remarkable history in the past. She was diagnosed invasive ductal carcinoma of right breast and received imaging survey for cancer staging. In transabdominal ultrasonography, a 6-cm hypoechoic cystic mass with an echogenic globular nodule, 2 cm in diameter containing some hyperechoic dots, was identified in the pelvis by accident (Figure 1A). Contrast enhanced computed tomography (CT) of pelvis demonstrated a well-defined ovarian tumor with fat-fluid level, containing round mass with hairlike matted tuft in the pelvis cavity (Figure 1B). Based on image finding, a mature ovarian cystic teratoma was diagnosed. Histopathological examination of this lesion after surgical excision confirmed the diagnosis.