Abstract

Teratomas are most commonly observed as lesions of ovarian origin. They can also be detected in extragonadal regions such as brain, face, neck, mediastinum, retroperitoneum, and sacrococcygeal region. Ovarian teratomas are usually in mature cystic form as benign, well-differentiated, and cystic lesions. Immature teratomas and monodermal teratomas (struma ovarii, carcinoid tumors and neural tumors) are rare forms. Mature cystic teratomas are usually diagnosed by ultrasound (US) and magnetic resonance (MR) imaging. On US, a variety of appearances including echogenic sebaceous material and calcification are observed. MR imaging can specifically demonstrate fat component by fat-saturation sequences. On the other hand, teratomas are usually incidentally detected on computed tomography (CT) and fat attenuation within a cyst is diagnostic. It may be difficult to characterize immature teratomas due to nonspesicific findings on US. However, CT and MR can provide diagnosis by identifying small foci of fat within a mass with irregular solid component containing coarse calcifications. A small proportion of mature cystic teratomas can undergo malignant transformation (carcinomas or sarcomas). The purpose of this paper is to review the imaging features of various types of abdominally located teratomas for differentiation and diagnosis.

Keywords: Computed tomography, dermoid cyst, magnetic resonance, ovary, teratoma, tumor, ultrasonography.

Graphical Abstract