I guess it could be either!
Depends on the history.
If there was an overloading injury it could be a damages A2 pulley.
It is certainly at the level of the A2 pulley.
It is also quite localised so I don’t think it is a tenosynovitis event (also no vascularity)
Remember it takes a large trauma to damage an A2 pulley so the patient will report a traumatic event.
We certainly see A2 degenerative changes with associated ganglion cysts.
What I think you are seeing is a degenerative change of the A2 pulley and rather than being a nice clean ganglion cyst, it is an area of “swiss cheese” appearance small cystic spaces.
Think of what we see in the anterior labrum of the hip, sometimes it is a clean paralabral cyst, but sometimes it is a swollen labrum with small tiny cystic areas within it. Either way we call it a labral tear / degenerative changes.
So same thing here.
Yes it could be a ruptured ganglion / cyst, or it might just be a multi cystic area.
Again, the history is important. Was there an acute onset of pain?
Steve.