skip to main content

Indeterminate Thyroid Nodule — RACP Adult Medicine MCQ

Instant feedback + full explanation. One question, done properly.

ModerateEndocrinology & DiabetesIndeterminate Thyroid NoduleRACP Adult Medicine

A 50-year-old woman with a 15 mm thyroid nodule undergoes FNA. Cytology returns as Bethesda III (atypia of undetermined significance/follicular lesion of undetermined significance). What is the recommended next step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Molecular testing or repeat FNA

Bethesda III (AUS/FLUS) has a malignancy risk of 10–30%. Options include repeat FNA in 6–12 weeks (to clarify the diagnosis) or molecular testing (if available) to refine the risk. If repeat FNA returns Bethesda III again, diagnostic hemithyroidectomy may be considered. Molecular panels (ThyroSeq, Afirma) can help reclassify indeterminate nodules and guide management decisions, reducing unnecessary surgery.

Reference: ATA – 2015 – Thyroid Nodule Management Guidelines; Cancer Council Australia – 2023