It is an unusual appearance,
Has there been trauma recently or in the past?
The calcium is very dense, so if it is calcific tendinosis it is old and chronic,
It is unusual to get an enthesophyte in this location that is as large as this,
If there has been trauma it may well be an old minimally displaced greater tuberosity fracture that has resulted in some bone remodelling.
There is a bit of a step in the greater tuberosity at the junction between the enthesis and the cartilage which is a good location for a fracture.
This patient needs a plain radiograph of the shoulder and then we can work it out.
Whenever you have an unusual bony appearance or dense calcium appearance a plain x-ray is essential to ensure there is not a fracture of something more sinister.
Load up the plain x-ray and I should be able to give you a nice answer.
It is a case of ultrasound needing the plain radiograph to assist in the correct diagnosis being reached.
Steve