The following glossary of terms is excerpted from Thyroid Cancer and Thyroid Nodules In 30 Minutes.

Anesthesiologist – A doctor who puts patients to sleep during thyroidectomies and other surgeries.

Asymptomatic – Not having any symptoms.

Beta-blocker – A drug that slows the heart rate or lowers the blood pressure.

Bethesda classification – A classification of cells to evaluate the risk of malignancy (ROM) in thyroid nodules.

Biomarker – A molecule whose presence in the blood can indicate the onset of disease.

Calcifications – Small calcium deposits in the thyroid gland that can show up on ultrasound and may raise the suspicion of cancer.

Calcitonin – Patients with medullary thyroid cancer (an unusual type of thyroid cancer) have elevated calcitonin levels.

Centimeter (cm) – A metric measurement of size or length. One inch equals 2.54 centimeters.

Chyle leak – If the thoracic duct is injured during surgery, the patient may develop leakage of intestinal lymph into the neck, which can lead to swelling of the neck and drainage of a whitish, milky fluid after surgery.

Completion thyroidectomy – An additional surgery to remove the remaining thyroid gland after a partial thyroidectomy.

Computer assisted tomography (CAT) – A diagnostic imaging technology based on computed tomography (CT). Also known as a CT scan.

Cytologist – A cytologist is a pathologist who specializes in the microscopic evaluation of cells obtained during a fine needle aspiration biopsy.

Cytology – Test results based on the examination of cells under a microscope.

Diagnostic lobectomy – When a lobectomy (removal of one half of the thyroid gland) is performed to make a definitive diagnosis, such as when there is a nodule with some suspicion of cancer.

Diffuse enlargement – The thyroid gland is enlarged without any nodules being present. The most common type of diffuse goiter is seen in patients with hyperactive thyroid glands.

Drain – A thin plastic tube connected to a small bulb with suction, placed by the surgeon after certain procedures.

Endocrine surgeon – A surgeon who specializes in the surgery of endocrine organs, in particular thyroid surgery.

Endocrinologist – A doctor who specializes in disorders of the endocrine organs, including thyroid nodules and cancer.

Esophagus – The muscular tube connecting the throat and stomach. Also known as the “food pipe.”

Euthyroid – Having normal levels of thyroid hormones in the blood.

Extrathyroidal extension – Growth of thyroid cancer beyond the thyroid gland into adjacent tissues.

Fine needle aspiration (FNA) – A doctor inserts a thin needle into a thyroid nodule to obtain a small number of cells, which are then subjected to a microscopic evaluation by a cytologist.

Follicular thyroid cancer – Second most common type of thyroid cancer, mainly made up of microscopic follicles (small sacs) lined by thyroid cells.

General anesthesia – Application of anesthesia to put patients to sleep during surgery.

General complications – Surgical complications that can occur after any type of surgery, such as bleeding or infection.

Goiter – Enlargement of the thyroid gland irrespective of the underlying cause.

Graves’ disease – Hyperactivity accompanied by diffuse enlargement of the thyroid gland.

Hashimoto’s disease – Chronic lymphocytic thyroiditis, or chronic inflammation of the thyroid gland, often leading to hypothyroidism.

Hemithyroidectomy – See lobectomy.

Horner’s syndrome – Caused by injury to the sympathetic trunk nerve structure during surgery. Symptoms include miosis (contracted, small pupil), ptosis (“hanging” upper eyelid), and anhidrosis (reduced sweating of the skin on the cheek).

Hűrthle cell cancer – Commonly referred to as follicular cancer of the oxyphilic type. Hűrthle cell cancer takes up radioiodine less well than cells from regular follicular cancer, and has a higher tendency to metastasize to regional lymph nodes.

Hyperactive – When a thyroid nodule or the entire thyroid gland produces increased amounts of thyroid hormones.

Hyperparathyroidism – Enlargement of parathyroid glands resulting in increased levels of parathyroid hormones and calcium.

Hyperthyroidism – Excessively high levels of thyroid hormones.

Hypervascularity – Increased blood flow.

Hypothyroidism – Insufficient hormone levels.

Incidental findings – When nodules are discovered for unrelated reasons, such as an x-ray following a car accident or ultrasound screening for hardening of the carotid arteries.

Intracuticular stitches – Stitches inside the skin

Isthmus – A thin bridge of thyroid tissue connecting the two lobes of the thyroid gland.

Isthmusectomy – Removal of only the isthmus.

Laparoscopic surgery – For thyroid surgery, procedures performed from the armpit (axillary) areas or through small incisions on the chest wall. Laparoscopes—a surgical instrument and camera mounted at the end of a thin tube—are inserted into the incision and tunneled under the skin up to the neck area. The instruments can also be inserted via small incisions on the inside of the lower lip, leaving no visible scars on the skin at all.

Larynx – The voice box.

Lobectomy – Surgery in which only one of the thyroid lobes is removed. Another term commonly used for this procedure is hemithyroidectomy.

Lobes – Parts of the thyroid gland. The thyroid gland has two lobes, one on each side.

Metastases – Cancer cells that have spread to another part of the body.

Microcarcinoma  A papillary thyroid cancer less than 1 cm in size.

Millicuries (mCi) – Unit of radioiodine dosage.

Multinodular goiter – Enlargement of the thyroid gland caused by multiple nodules.

Non-toxic – When a thyroid gland is not hyperactive and the patient has normal thyroid hormone levels.

NIFTP – Noninvasive follicular thyroid neoplasm with papillary-like nuclear features. A type of tumor that used to be classified and treated as a cancer but is  nowadays managed like a benign tumor.

Nuclear medicine specialist – A physician specializing in nuclear medicine, including radioiodine treatment.

Outpatient surgery – Surgery performed on the same day, requiring no overnight hospital stay.

Papillary thyroid cancer (PTC) – Most common type of thyroid cancer, characterized by papillae (protuberances covered by thyroid cells as seen under the microscope).

Parafollicular cells (or C-cells) – The parafollicular cells produce and secrete the hormone calcitonin. Medullary thyroid cancer originates in the parafollicular cells.

Parathyroid hormone – Produced by the parathyroid glands and regulates calcium levels in the body.

Partial thyroidectomy – Surgery in which only part of the thyroid gland is removed (for example, a thyroid lobectomy).

Pathologist – A medical doctor who uses a microscope and other laboratory techniques to diagnose thyroid and other tumors.

Pheochromocytoma – Tumor of the adrenal gland producing catecholamines.

Pituitary gland – Part of the brain that produces thyroid stimulating hormone (TSH).

Plummer’s disease – A thyroid gland with multiple hyperactive nodules.

Postoperative hypocalcemia – Low calcium levels in the blood stream after surgery.

Primary care physician (PCP) – A person’s regular family doctor. PCPs sometimes discover thyroid nodules and can help coordinate care with specialist doctors.

Prophylactic antibiotics – Antibiotics administered to reduce the risk of postoperative infection.

Prophylactic radioiodine – Radioiodine given to prevent thyroid cancer from returning in the future.

Radiologist – A doctor who specializes in imaging technologies, including x-rays and ultrasound.

Recurrent disease – Disease that returns. For instance, thyroid cancer coming back in a patient.

Recurrent laryngeal nerve – A nerve close to the thyroid gland regulating the movements of the vocal cord. If the nerve is injured during surgery, the patient may experience hoarseness and weakness of the voice after surgery.

Solitary nodule – The presence of only one nodule in the thyroid gland.

Specific complications – Surgical complications relating to the area of the body where the operation is performed.

Spinal accessory nerve – Regulates muscle function around the shoulder.

Stridor – A high-pitched wheezing sound caused by pressure on the trachea, for example by a large goiter. The sound is created by turbulence of the air when flowing through a narrowed trachea.

Subclinical hyperthyroidism – Minimal changes in TSH and thyroid hormone levels without symptoms of hyperthyroidism.

Supine – Lying on the back.

Surgical resection – Partial or total removal of tissue or an organ (for example, the thyroid).

Thoracic duct – A thin-walled tubular structure draining lymph from the small bowel – It ends up in the left neck and empties into the subclavian vein.

Thyroglobulin (Tg) – A thyroid-specific protein. Measurement of Tg is most commonly done in patients undergoing follow up after total thyroidectomy for cancer.

Thyroid cartilage – Commonly known as the Adam’s apple.

Thyroid scintigraphy – A nuclear medicine test visualizing functional thyroid tissue.

Thyroid stimulating hormone (TSH) – A hormone produced in the pituitary gland that stimulates hormone production in the thyroid gland.

Thyroid storm – A potentially dangerous situation caused by the certain outflow of hormones from the thyroid gland during surgery. It is characterized by rising heart rate, blood pressure, and body temperature.

Total thyroidectomy – Complete removal of the thyroid gland.

Toxic adenoma – A thyroid nodule producing thyroid hormones, with the patient having some degree of hyperthyroidism.

Trachea – Also known as the windpipe.

Transverse incision – During a thyroidectomy, a horizontal opening of the skin on the ventral aspect (front) of the neck.

Vocal cord paralysis – Total loss of vocal cord movements.

Vocal cord paresis – Weakness of the vocal cords.

Workup – A series of diagnostic tests, including blood test for thyroid hormone levels, ultrasound, and cytology after FNA.