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This page has moved. Click here to view. Solitary Thyroid NoduleSolitary thyroid nodule (STN) affects between 4 and 8 percent of the general population, and its prevalence increases with age thyroid cancer, thyroid adenoma, thiroid, hashimoto's thyroiditis. Most STNs are found during routine medical evaluation. The vast majority of STNs are benign and, most frequently, colloid nodules. Carcinoma is present in 5 to 30 percent of palpable thyroid nodules thyroid cancer, thyroid adenoma, thiroid, hashimoto's thyroiditis. The challenge for the physician is to determine 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 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 (Table 23). A number of additional issues should also 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. STN occurring at extremes of age is more likely to be cancerous. In children, STN is malignant in 30 to 50 percent of cases.,6E The incidence of carcinoma in patients with STN who are over age 50 increases progressively. STN in a man over age 50 is much more likely to be malignant than STN in a woman of the same age. The patient in Case 8 is 40 years old; both benign and malignant thyroid diseases occur in 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 represents thyroid cancer.~ An increased incidence of thyroid cancer has also been reported in families with histories of breast, renal, or central nervous syndrome malignancy.~ In addition, women with a personal history of breast cancer are at increased risk for developing thyroid cancer. 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 and mucosal neuromas (MEN-2B). Thus, a family or personal medical history of long-standing constipation, diarrhea, pheochromocytoma, hyperparathyroidism, hypertension, or episodes of flushing or nervousness should arouse suspicion of Table 23 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
A family history of differentiated thyroid cancer (papillary or follicular) is not a significant risk factor for thyroid cancer in an STN; however, 5 to 8 percent of patients with differentiated thyroid cancer report that another family member has a history of thyroid cancer. These patients may be more compelled to have the nodule thoroughly evaluated because of fear of an Exposure to Ionizing Radiation. Radiation of the head and neck region and the upper chest was frequently used in the mid-1950s and 1960s to treat conditions ranging from cystic acne to adenotonsillar hypertrophy. An increased incidence of thyroid nodules has been reported in association with low to high doses of radiation in the head and neck region.5s,6~ Also, STN is more likely to be malignant in a patient with a history of irradiation. The incidence of malignancy in thyroid nodules in patients with a history of radiation ranges from 30 to 50 percent. Current radiation treatment for lymphoma (Mantel technique) and other head, neck, and chest neoplasms is also associated with an increased risk for malignancy in an STN. Thyroid Diseases. Most patients with a recently discovered STN are euthyroid. A patient with known Graves' disease who presents with an STN deserves comprehensive evaluation because of the high incidence of carcinoma in these nodules. Hashimoto's thyroiditis is often associated with primary thyroid lymphoma. A dominant thyroid nodule in a multinodular goiter Thyroid Hashimoto's thyroiditis Acute suppurative thyroiditis Subacute thyroiditis Hemorrhage into thyroid cyst Hemorrhage into thyroid adenoma Anaplastic carcinoma AIDS (Pneumocystis carinii thyroiditis) Nonthyroid Infected branchial cleft cyst Cellulitis Infected dermoid cyst Lymphadenitis Infected thyroglossal duct cyst Metastases and neoplasms Degenerative vascular diseases, aneurysm cyst. Hashimoto's thyroiditis may present as a unilateral nodule, but the gland is usually quite firm, and distinct nodules are uncommon. Acute suppurative thyroiditis may be caused by trauma or hematogenous or local spread of infection. It is more often seen in children and may be associated with severe systemic symptoms. Subacute thyroiditis may present with flu-like symptoms, high fever, and mild thyrotoxicosis. Although thyroid enlargement in |