Hi there
Keep your eye on it!! My all time best was a litre and a half and no, I am not exaggerating!! If your body is as keen on helping you to heal as mine was, it can and may refill. Apart from the weight (and the sloshing and the difficulty with a prosthesis, which le it's waxing and waning), a warm fluid filled spot in the body is heaven for bugs and infection can occur (from bacteria already naturally in your body).
Massage can help - a good lymphoedema therapist is a good choice, but check with your oncologist.
Most seromas do go away naturally or after aspiraration, so you'll probably be fine, but if it lingers get some action. Mine hung around for ridiculous amount of time and finally had to be surgically cleaned out, but all fine since.
Good luck.
