Palpable mass on the lateral side of the popliteal fossa.

The mass is characteristically eccentric with respect to the affected nerve, and the nerve is displaced to the periphery of the mass. 

The ultrasound picture allows us to distinguish the internal structure of the lesion accurately and study the entire course of the nerve. 

The histologic architecture of the mass is with more myxoid material peripherally and more fibrous tissue centrally. 

The study with elastosonography shows the different structural characteristics of the various components of the mass, distinguishing between the “softer” mixoids and the “harder” fibrous ones.

My suggestion is always to combine MRI and ultrasound examinations to define these kinds of lesions better.