Introduction Found in 1% of individuals from 20-30, 5% greater than 30 Benign cysts or goiters (60%) cysts are usually part of a multinodular goiter and are generally benign follicular adenoma (25%) Malignant medullary carcinoma / anaplastic carcinoma Evaluation Thyroid Function tests Patients suspicious of malignancy usually present with low T3/T4 Typically nodules are hypofunctional Some prefer to start with an ultrasound to determine if cystic or solid ultrasound if solid, then FNA if malignant, surgical resection if benign, treat with thyroxine and follow with ultrasound if inconclusive, then lobectomy and wait for pathology (some do a scan first) if cold, then resect if hot, then follow with ultrasound if cystic, then treat with thyroxine and follow with ultrasound The majority start with a fine-needle aspiration Thyroxine suppreses TSH and shrinks nodule