myxoid degeneration of a leiomyoma
While this type of degeneration is generally considered rare, the highest prevalence for this type of degeneration has been reported as up to 50% of all degenerations of leiomyomas .
Fibroids (i.e. uterine leiomyomas) that have undergone myxoid degeneration are filled with a gelatinous material and can be difficult to differentiate from cystic degeneration; however, they typically appear as more complex cystic masses. They appear hypocellular with a myxoid matrix .
On pelvic MRI, the myxoid material usually demonstrates :
- T1: low signal intensity
- T2: usually high signal intensity with a peripheral low signal intensity
- T1 C+ (Gd): there is minimal or no enhancement
The above signal changes are of intralesional change on a background of low T2 signal of non-myxoid components.
Certain malignant uterine tumors also show myxoid degeneration, e.g.leiomyosarcoma