Hello, last year I had an ectopic pg and when they discovered that on the left side they found a 6cm cyst on the right side! Both the u/s operator and my Doctor told me that as there was solid/hard particles inside the tumour it was extremely unlikely to go away and I was put on a waiting list for keyhole surgery. A couple of months later when I received my surgery date I went in for another u/s to see if it had grown and to get the exact location and it had disappeared! The u/s operator couldnt believe it and had 2 other specialists come in the room to look as well and they all confirmed it! So even the cysts they say won't go away on their own sometimes do!