Well this is all very fascinating. I'll try to sum all this up in a way that makes sense

Leigh, I also passed something that looks an awful lot like your photo of an ovary. But without the red/orange cysts. It was whitish and fleshy and approx golf ball size (but a little squished - not as round).
The thing is, it was a few cycles after a miscarriage that was likely (although not officially diagnosed as such) a blighted ovum. And I'm 99% sure I passed the sac and pieces of placenta (way prior to this) - so I'm almost *positive* that the whitish fleshy thing was NOT a blighted ovum. This whitish thing was not all vascular like the placenta pieces, and it wasn't a sac and didn't have anything inside it - just a chunk of fleshy material. I had several hours of horrible cramping and then it just appeared with a plop. I know I ovulated prior to passing the fleshy material and it passed during my period.
Also, when I had the ultrasound that diagnosed the impending miscarriage, doc (very experienced w/ ultrasounds - like 22+ years) said my ovaries looked good and did not note anything particularly unusual about the situation. I think that would most likely rule out any uterine growths.
We're actually TTC and I'm (duh) not on the pill. I just kind of assumed this was somehow miscarriage related, but I wasn't able to find pictures even close to what I saw. It's really hard to search for.
So I'm really curious to find out what it was that you passed.