I had a diagnosis of hurthle cell cancer based on vascular invasion of the tumor. The first surgery excised the lobe with the tumor and the isthmust. A second surgery removed the other lobe and ablation followed. Apparently surgery is necessary to biopsy the entire tumor and then make a judgment based on blood vessels.
I'm dealing with hurthle cells myself. My FNA biopsy came back benign, but with "abundant hurthle cells".
From what I've read, hurthle cells can be in tumors that are benign and that are malignant. I've also read that the only true diagnosis for hurthle cell carcinoma is with surgery. I've read medical papers that suggest that any FNA biopsy with over 50% hurthle cells should be treated surgically. I also read one paper that was much more aggressive and suggested that any FNA biopsy findings with hurthle cells should be treated surgically, but I don't know where the medical community currently stands on the issue.
I see a surgeon next week, so I guess I'll find out then.