Ok thx..I'll ask in the expert forum
It looks like stretch marks to me too. Have you recently put on weight or muscle in that area? Stretch marks fade over time to a silver/grey colour.
Please see a doctor though.
You should post this in the Expert's forum because there are no doctors here, but anyway, I'm not an expert, but to me it looks like stretch marks. I would go to the doctor anyway and see what he/she thinks it is.