Ovarian Teratoma | Figure 1

Ovarian Teratoma

Image description
Axial abdominal radiograph (image 1) shows a cluster of dysmorphic calcifications in the left lower pelvis (arrow). Axial contrast-enhanced CT (image 2) demonstrates a left ovarian mass (arrow) containing macroscopic fat and calcified components.

Teaching point

Mature ovarian teratomas are composed of elements from multiple germ layers and commonly contain macroscopic fat and calcification. Fat density within an ovarian mass, especially when combined with coarse or tooth-like calcifications, strongly favors this diagnosis. In pediatric and adolescent patients, the mass effect of a teratoma increases susceptibility to adnexal twisting.

Diagnosis added by author

Ovarian Teratoma

A 15 year old previously healthy girl presented to the casualty with one-day history of paraumbilical pain that shifted to the right iliac fossa soon after. She vomited once and was anorexic as well. Examination revealed rebound tenderness and guarding in the right iliac fossa, making a diagnosis of acute appendicitis more plausible. A CT abdomen was done, however, and showed signs of appendiceal inflammation with fat stranding. That wasn’t all though, the radiologist also noticed the presence of bilateral heterogenous ovarian masses with a calcific component.

Immature Teratoma
Axial CECT (#1-3) shows a right ovarian mass (white arrows, #1-3) that appears separate from the uterus (black arrow, #1) and the left ovary (curved black arrow, #1), which contains a simple-appearing cyst. The right ovarian mass is heterogeneous in attenuation, and it is composed mainly of soft tissue attenuation with islands of fat attenuation (open white arrows, #2-3) and punctate calcifications (curved white arrow, #3).

Coronal T2-weighted (image 1), T2-weighted with fat saturation (image 2), axial T2-weighted (image 3), and axial T2-weighted with fat saturation (image 4) MR images show a teratoma of the left ovary (arrow). The mass contains fat which loses signal on the fat-saturated images. A solid component (arrowhead) is present in the inferior aspect of the mass. Calcification is likely present within this portion of the mass. Ovarian teratomas are the most common ovarian germ cell tumor and the most common ovarian neoplasm in a child. Teratomas are often incidental findings identified via imaging for unrelated symptoms or may act as a lead point for ovarian torsion.