Which test provides cytology to confirm a thyroid nodule diagnosis?

• A. Ultrasound
• B. MRI
• C. Fine-needle aspiration biopsy
• D. X-ray

Answer: (C)

Fine-needle aspiration biopsy provides cytology from a thyroid nodule. By inserting a small needle into the nodule (often under ultrasound guidance) and aspirating cells, a pathologist can examine those cells under a microscope to determine whether the lesion is benign or malignant and to identify suspicious cytologic features. Imaging tests like ultrasound help characterize the nodule and guide the biopsy but do not yield cellular material or a definitive diagnosis; MRI and X-ray do not provide cytology for confirming thyroid nodules.