SU22.1-6 | Thyroid and Parathyroid Surgery — Glossary

Undifferentiated, rapidly progressive thyroid cancer of the elderly with very poor prognosis.

Standardised reporting of thyroid FNAC in six categories (I–VI) stratifying the risk of malignancy and guiding management.

Surgical inspection of all four parathyroid glands, used when localisation is equivocal or four-gland hyperplasia is suspected (e.g. in MEN syndromes).

A hormone secreted by parafollicular C cells; raised levels serve as the tumour marker for medullary thyroid carcinoma.

The receptor on parathyroid cells that detects serum calcium and adjusts PTH secretion by negative feedback.

A twitch of the facial muscles on tapping over the facial nerve, indicating the neuromuscular irritability of hypocalcaemia.

Papillary and follicular carcinomas, which arise from follicular cells and retain iodine uptake, making them responsive to radioiodine therapy.

Supplies cricothyroid; injury during upper-pole ligation produces a weak, easily fatigued voice.

A benign inherited cause of hypercalcaemia with low urinary calcium that mimics primary hyperparathyroidism and must not be treated surgically.

Fine-needle aspiration cytology — the key test for sampling a thyroid nodule, reported by the Bethesda system.

Minimally invasive removal of a single, pre-operatively localised parathyroid adenoma, often guided by intra-operative PTH monitoring.

Follicular-cell cancer spreading haematogenously to lung/bone; diagnosis needs histological capsular/vascular invasion, not FNAC.

Any enlargement of the thyroid gland, classified by pattern (diffuse vs nodular) and aetiology.

Removal of one thyroid lobe and the isthmus, used for indeterminate or low-risk unilateral nodules.

Deficient PTH secretion causing hypocalcaemia; most commonly iatrogenic after thyroid or parathyroid surgery, or autoimmune.

Branch of the thyrocervical trunk supplying the lower pole; closely related to the recurrent laryngeal nerve and the parathyroids.

Measurement of PTH during parathyroid surgery; a fall of more than 50% after excision confirms that the overactive gland has been removed.

The midline bridge of thyroid tissue joining the two lobes, overlying the upper trachea.

Removal of one thyroid lobe; used diagnostically for indeterminate follicular lesions and therapeutically for small, low-risk differentiated cancers.

Cancer of calcitonin-secreting parafollicular C cells, associated with MEN-2.

Multiple endocrine neoplasia type 2 (2A and 2B); familial syndromes featuring medullary thyroid carcinoma, phaeochromocytoma and (in 2A) hyperparathyroidism, caused by RET mutations.

A thyroid enlarged by multiple nodules, often long-standing and benign but capable of harbouring malignancy.

Surgical removal of cervical lymph nodes; performed when nodal metastases are present and routinely in medullary carcinoma.

The characteristic bone resorption and cystic change seen in severe long-standing hyperparathyroidism.

Commonest thyroid cancer; follicular-cell origin, lymphatic spread, excellent prognosis (psammoma bodies, Orphan-Annie nuclei).

A benign tumour of a single parathyroid gland; the commonest cause (~85%) of primary hyperparathyroidism.

Four glands on the posterior thyroid controlling calcium; inadvertent removal/devascularisation causes hypocalcaemia.

The master regulator of serum calcium; it raises calcium by acting on bone, kidney and (via vitamin D) the gut, and is controlled by negative feedback through the calcium-sensing receptor.

Autonomous excess secretion of PTH — most often from a single adenoma (~85%) — producing high serum calcium with a high or inappropriately normal PTH.

Laminated calcified concretions seen histologically in papillary thyroid carcinoma (among other tumours).

Administration of radioactive iodine after total thyroidectomy to destroy residual thyroid tissue and micrometastases in differentiated thyroid cancer.

Supplies all intrinsic laryngeal muscles except cricothyroid; unilateral injury causes hoarseness, bilateral injury threatens the airway.

A gene whose mutations drive medullary thyroid carcinoma and the MEN-2 syndromes; the basis for genetic testing and family screening.

An appropriate compensatory rise in PTH driven by chronic hypocalcaemia, classically from chronic kidney disease or vitamin D deficiency, with low or normal calcium.

Technetium-99m sestamibi scintigraphy used, with ultrasound, to localise a parathyroid adenoma before focused parathyroidectomy.

A single discrete thyroid swelling that must be worked up (TSH → ultrasound → FNAC) to exclude malignancy.

First branch of the external carotid supplying the upper pole; closely related to the external laryngeal nerve.

Autonomous PTH secretion that persists after long-standing secondary hyperparathyroidism (e.g. after renal transplantation), giving high serum calcium.

A protein used as a surveillance marker after total thyroidectomy for differentiated thyroid cancer; a rising level suggests recurrence.

The embryological tract of thyroid descent from the foramen caecum; its remnants form thyroglossal cysts that move on tongue protrusion.

Removal of the entire gland, used for confirmed carcinoma or bilateral disease; risks nerve palsy and hypoparathyroidism.

Carpopedal spasm provoked by inflating a blood-pressure cuff above systolic pressure, a sign of latent tetany in hypocalcaemia.

Thyroid hormone given at a dose that suppresses TSH after surgery for differentiated cancer, both replacing hormone and reducing the growth drive to any residual tumour.