What are the imaging features of a mature teratoma of the ovary?
A mature teratoma on US is identified as a cystic or echogenic mass with distinct features such as thin, echogenic lines representing hair, posterior acoustic shadowing from calcifications including bone and teeth, and fluid-fluid levels from sebum layering with serous fluid.
On CT, fat attenuation with or without calcification is diagnostic for a mature teratoma. On MRI, high T1-weighted signal intensity may indicate the presence of fat or hemorrhage within a mass.
Using fat suppression techniques on MRI, one can differentiate a mature teratoma from a hemorrhagic cyst or endometrioma, as the former will lose signal intensity on fat-suppressed T1-weighted images, whereas the latter will not.
Mature teratoma can be associated with complications such as torsion (common), malignant degeneration (rare, <2%), or rupture (rare <1%), sometimes with associated chemical peritonitis.