Fat migrated behind muscle after 10 months? (Photo)

Hello. I had saline implants removed two years ago; a year later, I had fat transferred to my breasts. Last week, the top of my right breast suddenly ballooned. After extensive testing, doctors discovered that I hada large pool of very inflamed fat behind my pectoral muscle on the right side. There was no fat behind my left pectoral muscle. The diagnostic doctor called my plastic surgeon, who did the surgery 10 months ago. His office called me and said the fat migrated. Is that possible?