What is a Thyroid nodule?

A thyroid nodule is a lump in an otherwise normal thyroid gland. Thyroid nodules are very common and it has been estimated that one in every 12-15 women and one in every 40-50 men have a thyroid nodule. Less than 5% of these nodules are malignant and many are cysts. The most common types of benign thyroid nodules are adenomas (benign overgrowths of normal thyroid tissue), cysts and Hashimoto's Thyroiditis. Uncommon types of benign thyroid nodules are due to subacute thyroiditis, silent thyroiditis or Reidel's thyroiditis. Papillary carcinoma accounts for almost 60% of malignant nodules and follicular carcinoma almost 15%. These malignant carcinomas are well differentiated and have a good prognosis.