What is a ganglion cyst?

My brilliant sister ended up at the hospital because of this growth on her foot. They checked her out and told her she needs surgery, but she didn't even bother asking what was actually wrong with her.
The report says "hygroma pedis sin."
Does anyone have a clue what that actually means?
I tried searching for it online, but honestly, Google hasn't been any help at all.
Thanks in advance.

It’s really nothing to lose sleep over... just a benign soft tissue cyst filled with some gelatinous gunk. It tends to wrap itself tightly around a joint or a tendon, which is why you end up dealing with that nagging pain and losing some grip strength. It isn't cancerous—no risk of malignancy there. As for what causes it? Nobody knows for sure, though I've heard it's likely due to repetitive strain or minor trauma over time. You see them most often on hands and feet, and they seem to pop up more frequently in women...

If you want to fall down a rabbit hole and read up on it, just search Google for "hygroma" or "ganglion cyst."

gentlehound9 said:My brilliant sister ended up at the hospital because of this growth on her foot. They checked her out and told her she needs surgery, but she didn't even bother asking what was actually wrong with her.
The report says "hygroma pedis sin."
Does anyone have a clue what that actually means?
I tried searching for it online, but honestly, Google hasn't been any help at all.
Thanks in advance.

We've already discussed ganglions on this forum before—do a little digging.

thanks so much