Hurthle cell thyroid cancer is usually classified with follicular thyroid cancer, although it really is a distinct kind of tumor. It is an unusual tumor, making up about 4% of thyroid cancers and is only about one-fourth as common as follicular cancers.
- What is a Hurthle Cell? A Hurthle cell is a kind of thyroid cell which has a distinctive look: under the microscope it is bigger than a follicular cell and has pink-staining cellular material.
- Is the Hurthle Cell Tumor Benign or Malignant? Like follicular tumors, there are benign Hurthle cell tumors and malignant Hurthle cell tumors, and the pathologist tells the difference between them based on invasion of the capsule and the blood vessels. Benign Hurthle cell tumors are not a threat at all and should not come back once they are removed.
- How Is Hurthle Cell Cancer Different from Follicular Cancer ? Hurthle cells look different than other types of thyroid cells, and they tend to occur in older patients. The median age is patients with Hurthle cell cancer is 55, about 10 years older than patients with follicular cancer. Like follicular cancer, Hurthle cell thyroid cancer infrequently spreads to lymph nodes (about 10%) but can recur locally (the cancer can come back in the neck) or spread to lung or bone.
Because younger patients with thyroid cancer tend to have a better prognosis than older patients with a very similar tumor, and because Hurthle cell cancers occur in older patients, they have the reputation of being more dangerous. However, if you control for age and other factors like size and initial extent of tumor (whether it has spread locally in the neck or elsewhere in the body), Hurthle cell tumors behave very similarly to follicular tumors. A small Hurthle cell cancer which does not have extensive invasion, especially in a younger patient (under 45), can have an excellent prognosis.
- How Is Hurthle Cell Cancer Treated? Patients with Hurthle cell thyroid cancer, if there is more than minimal invasion, should generally undergo removal of all or nearly all of their thyroid tissue (see our article on the different types of thyroid surgery). In all areas of well-differentiated thyroid cancer, there is some disagreement about how extensive the surgery should be; however, because Hurthle cell tumors tend to occur in patients with more serious risk factors, the surgery is correspondingly more aggressive. If there are involved lymph nodes, they are removed, although this is uncommon.
Surgery may be followed with radioactive iodine. Radioactive iodine does not work as well for Hurthle cell cancer as it does for follicular cancer, because the Hurthle cells are less likely to "take up" the radioactive iodine and then be destroyed by it. However, it is well-tolerated treatment and may be helpful in some cases. Patients are then followed at regular intervals to check for recurrence, which can be dangerous in Hurthle cell cancer and needs to be watched for carefully.
About the Author: James Norman, MD, FACS, FACE, is recognized as one of world's foremost experts on parathyroid disease and the most experienced thyroid/parathyroid surgeon in the world. He is a Fellow of the American College of Surgeons (FACS) and one of only a handful of surgeons to also be a Fellow of the American College of Endocrinology (FACE). He is recognized as the inventor of minimally invasive radioguided parathyroid surgery in the mid-1990s and is credited with dramatically changing the way parathyroid surgery is performed.