Very rare, Transformation into Sarcoma

Hello All,
My husband was originally diagnosed with Testicular Cancer, however three tumours contained Teratoma in his retroperitoneal area transformed into Fibro Sarcoma. It was complete dissected in Aug 2011 and since then thankfully all clear for 6months.
This transformation is very rare to happen and so we have been having a hard time to find some resources to find a real long term survivors with the similar situation.
If anybody experienced the transformation or knows about survival stories and information, I would love to hear about it.
Thank you very much.