Click here to view next page of this article Thyroid NoduleA thyroid nodule (STN) affects between 4 and 8 percent of the general population, and its prevalence increases with age. Most STNs are found during routine medical evaluation. The vast majority of STNs are benign and, most frequently, colloid nodules thyroid nodule, thyroid mass, lump. Cancer is present in 5 to 30 percent of palpable thyroid nodules. The challenge for the physician is to determine whether an asymptomatic STN may be malignant, a problem made more complicated by the fact that almost any thyroid disease can present as a thyroid nodule. The significance of asymptomatic STN is debatable. Autopsy reports have shown a 50 percent incidence of asymptomatic thyroid nodule in patients over age 50 and a 60 percent incidence in patients over age 70. The incidence of occult thyroid carcinoma in autopsy specimens is about 10 percent. Although single palpable thyroid nodules often prompt the initial evaluation, many glands are found. Nonfunctional Thyroid Diseases Presenting as a Solitary Thyroid Nodule Type of nodule Comments Simple colloid Approximately 40 percent of all nodules Adenomas Follicular adenomas are the most frequent neoplasm Carcinomas Papillary, follicular, medullar, Horthle cell, anaplastic Thyroid cysts Simple cysts, hemorrhagic colloid, 20 to 25 percent Inflammatory thyroid Acute thyroiditis, disease Hashimoto's thyroiditis Asymmetric thyroid Occasionally, thyroid enlargement unilateral agenesis Parathyroid Rarely carcinoma cyst/adenoma Metastatic carcinomas Breast, kidney, prostate Thyroid lymphoma Associated with Hashimoto's thyroiditis Benign tumors Neurofibroma, hamartoma, paraganglioma, teratoma, hemangioma HISTORY AND PHYSICAL EXAMINATION In this case, the physician's objective is to determine whether the recently discovered asymptomatic STN has a significant malignancy potential. A detailed medical history and targeted physical examination are important to uncover risk factors for thyroid cancer. Age and Gender. Palpable nodular disease is more common in women than men and is most likely to be discovered in patients between ages 21 and 40.s4'sS,59 The incidence of carcinoma found in STN is greater in men than women. Family History. Patients with familial colonic polyposis (Gardener's syndrome) and familial goiter and hamartomas (Cowden's syndrome) have an increased risk for developing thyroid cancer and, thus, an increased probability that any nodule. Cancer can metastasize to the thyroid gland and present as a palpable nodule. Medullary thyroid carcinoma (MTC) is frequently seen in families with a history of thyroid cancer. In these families, MTC occurs alone or as a component of multiple endocrine neoplasia (MEN) in association with either pheochromocytoma and hyperparathyroidism (MEN-2A) or pheochromocytomas.
Risk of Cancer in Thyroid Nodule High risk Medical history History of radiation Multiple endocrine neoplasia type 2 Cowden's syndrome Familial polyposis Hoarseness Rapid growth, recent change in size Solitary nodule Male gender Younger or older age group Recurrent cystic nodule Compressive symptoms Nodules refractory to suppression Suspicious fine-needle aspiration biopsy results Physical examination Vocal cord paralysis Cervical lymphadenopathy Fixation to adjacent tissues or laryngotracheal complex Hard, nontender nodule Horner's syndrome Superior vena cava syndrome Nodules larger than 4 cm Distant metastases Low risk Medical history Family history of benign goiter Slow-growing or stable nodule Symptoms of hyper- or hypothyroidism Physical examination Multinodular goiter with no dominant nodule Tenderness or inflammatory changes Soft, cystic mass
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