Typical example of nodular fasciitis of the myxoid subtype.
Subcutaneous lesions tend to belong to a myxoid subtype and to be of younger age.
- Ultrasound is helpful in determining whether the lesion is cystic or solid. The lesion can be of mixed echogenicity and sometimes the lesion presents as a low-level vascular lesion on doppler ultrasound despite the intense neovascularity visible on angiography
- On MRI the myxoid subtypes show
- homogeneous SI comparable with normal muscle on T1
- high SI on fat saturation proton-density or T2 weighted images
- they usually show mild to moderate enhancement, which is diffuse but slightly inhomogeneous
- The increased T2 SI is most likely caused by fluid-filled mucoid spaces. Compact cellularity with a prominent capillary network and a myxoid pattern may be responsible for the enhancement on MRI.