AKT · ENT/Neck & thyroid

Thyroid nodule

Discrete lump within the thyroid (mostly benign)

Overview

A discrete swelling within the thyroid gland — very common and usually benign (colloid nodule, cyst, adenoma), but a minority are malignant. Assessment combines thyroid function, ultrasound (with a risk-stratification grade), and FNA cytology, triaging which nodules need surgery.

Recognise

A palpable, usually painless, thyroid lump that moves up on swallowing
Mostly euthyroid; a "hot" (toxic) nodule may cause hyperthyroidism (and is rarely malignant)
Most are benign — but assess malignancy risk in every nodule

Red flags

Features raising malignancy concern: rapid growth, a hard/fixed nodule, hoarseness (recurrent laryngeal nerve), cervical lymphadenopathy, age 60, male sex, or prior neck irradiation

Differentials & how to tell them apart

Multinodular goitremultiple nodules; dominant nodules still need assessment

Thyroid cystfluid on ultrasound; usually benign

Thyroid carcinomasuspicious ultrasound + FNA cytology — the reason every nodule is risk-assessed

Toxic adenomahyperthyroidism with a "hot" nodule on uptake scan, rarely malignant

Investigations

Thyroid function tests + ultrasound (U/TIRADS risk grading) → FNA cytology (Thy classification) for nodules meeting size/risk criteria. A toxic nodule (suppressed TSH) → uptake scan (and is rarely cancer).

Management

TFTs + ultrasound → FNA by risk; observe benign, refer suspicious

1Assess with thyroid function tests and ultrasound risk-grading; perform FNA cytology of nodules meeting size/risk criteria.Gate: A suppressed TSH means do an uptake scan first — a "hot" (toxic) nodule is almost never malignant and does not need FNA, whereas a non-functioning nodule with suspicious ultrasound does
2Benign/low-risk → surveillance; indeterminate/suspicious/malignant cytology → surgery (diagnostic hemithyroidectomy or total thyroidectomy); treat any associated thyroid dysfunction.

Observation — benign, low-risk nodules — surveillance

Levothyroxine / antithyroid drugs as appropriate — treat associated thyroid dysfunction

Hemithyroidectomy/thyroidectomy — suspicious/malignant cytology, compressive symptoms, or toxic nodule

Key points

Most nodules are benign, but every one is risk-assessed (US grade + FNA). A toxic "hot" nodule is reassuringly almost never cancer. Hoarseness or fixation/lymphadenopathy raises real concern.

Monitor & prognosis

Ultrasound surveillance; cytology; thyroid function.

Excellent for benign nodules; depends on histology if malignant.

Source: British Thyroid Association; NICE NG145 (thyroid disease)