Thyroid Surgery: Types
There are three main thyroid operations:
1. Thyroid lobectomy
This operation involves removing the half of the thyroid gland that has the nodule. It is sometimes called a "diagnostic lobectomyLobectomy - removal of half the thyroid" because the preoperative diagnosis may be uncertain and part of the reason for the operation is to make a diagnosis of cancer or no cancer. These patients may have had a FNAFNA - fine needle aspiration biopsy biopsy result that is non-diagnostic, suspicious for malignancy, or shows a follicular or Hurthle cell neoplasmHurthle cell neoplasm - variant of follicular neoplasm.
A diagnostic lobectomy may or may not involve a frozen sectionFrozen section - tissue taken during an operation that is given to the pathologist to evaluate the thyroid lobe and make a preliminary diagnosis while the patient is still on the operating room table. A frozen section is biopsy of the nodule that is taken during the operation while the patient is still under anesthesia. The pathologist will examine one or two slices of the thyroid nodule under the microscope and try to make a diagnosis. If definite cancer is found on the frozen section, then the patient would likely have a total thyroidectomyTotal thyroidectomy - removal of the whole thyroid. It is important to note that frozen section is not 100% accurate. Since the pathologist is looking at only one or two slices of the nodule, there is a good chance that there may be evidence of cancer, just not in the slices that are examined. More often than not, the pathologist cannot make the diagnosis of follicular or Hurthle cell cancer on frozen section and it is necessary to wait for the final pathology (permanent sections that require special processing and allow for the entire specimen to be reviewed). The final pathology usually is ready about 5-7 business days after the surgery. If the cancer is not found on the frozen section, but found on the final pathology, then a second surgery may be needed to remove the rest of the thyroid gland (completion thyroidectomyCompletion thyroidectomy - when a lobectomy is performed and the pathology comes back that the lobe had cancer, the remaining lobe is surgically removed as well.). Ultimately, whether or not to send a frozen section will depend on the experience and expertise of the surgeon. (See Frozen section)
All patients that have one half of the thyroid gland removed will need to have their thyroid levels checked sometime after surgery. Depending on these levels, some patients may need thyroid hormone replacement and some patients will not.
2. Total or Near-total thyroidectomy
This operation involves removing all or nearly all of the thyroid gland. It may be done for benign thyroid conditions that affect both thyroid lobes, such as large goiterGoiter - enlarged thyroid or Graves' diseaseGraves' disease - autoimmune overproduction of thyroid hormone resulting in hyperthyroidism, or it may be done for cancer. A near-total thyroidectomy means that the surgeon decided to leave a very small amount of benign thyroid tissue behind. Thyroid tissue may be intentionally left behind in areas around important structures, such as the nerves that control the voice, swallowing, and breathing, or the parathyroid glands. All patients who undergo a total or near-total thyroidectomy will need to be on life-long thyroid hormone replacement after surgery.
3. Completion thyroidectomy
A completion thyroidectomyCompletion thyroidectomy - when a lobectomy is performed and the pathology comes back that the lobe had cancer, the remaining lobe is surgically removed as well. involves removing the remaining thyroid tissue after a patient has had a previous partial thyroid resection (i.e. lobectomy). It may be done years later or it may be done soon after a lobectomy (as early as the next week). The reasons for completion thyroidectomy are the same as for a lobectomy or total thyroidectomyTotal thyroidectomy - removal of the whole thyroid. All patients who undergo a completion thyroidectomy will need to be on life-long thyroid hormone replacement after surgery.