A thyroid nodule is a palpable swel...

A thyroid nodule is a palpable swelling in a thyroid gland with an otherwise normal appearance. Thyroid nodules are general and may be caused according to a variety of thyroid disorders. While mostly are benign, about 5 percent of all palpable nodules are malignant. (1-4) Many proofs and procedures are available for evaluating thyroid nodules, and appropriate selection of proofs is important for accurate diagnosis. Family physicians should have a cost-effective system of differentiating between nodules that are malignant and those that will have a benign course. This article provides a orderly disposition for the outpatient evaluation and treatment of thyroid nodules.

Epidemiology

Palpable thyroid nodules offer in 4 to 7 percent of the population (10 to 18 million persons) on the contrary nodules found incidentally on ultrasonography allude to a prevalence of 19 to 67 percent (15) In single study, (6) 30 percent of exposes 19 to 50 years of age had an incidental nodule forward ultrasonography. In addition, more than single half of the thyroid glands studied contained single or more nodules, with merely about one in 10 being palpable. (6) Approximately 23 percent of solitary nodules are actually dominant nodules within a multinodular goiter. (7) Thyroid carcinoma meet the eyes in roughly 5 to 10 percent of palpable nodules. (1) Of the estimated 1268000 cancers that were count uponed to be newly diagnosed in 2001 in the United States, 19500 were awaited to be of thyroid origin with 1300 deaths attributable to thyroid cancer. (8)

Thyroid nodules are four times more usual in women than in men (9) and be met with more often in people who live in geographic areas with iodine deficiency. (5) After aspect to ionizing radiation, thyroid nodules disclose at a rate of 2 percent annually. (9)

Presentation

The majority of thyroid nodules are asymptomatic. in the greatest degree persons with thyroid nodules are euthyroid, with les than 1 percent of nodules causing hyperthyroidism or thyrotoxicosis. Patients may complain of neck press or pain if spontaneous hemorrhage into the nodule has occurr Questions about symptoms of hypothyroidism or hyperthyroidism are essential, as are questions about any nodule, goiter, family history of autoimmune thyroid disease (eg Hashimoto's thyroiditis, Graves' disease), thyroid carcinoma, or familial polyposis (Gardner's syndrome)

The various emblems of thyroid nodules are listed in Table 1 Colloid nodules are the in the greatest degree common and do not have an increased risk of malignancy. most numerous follicular adenomas are benign; however, any may share features of follicular carcinoma. About 5 percent of microfollicular adenomas suffer to be follicular cancers with careful contemplation (1) Thyroiditis also may ready as a nodule (Figure 1) Thyroid carcinoma usually readys as a solitary palpable thyroid nodule. The most numerous common type of malignant thyroid nodule is papillary carcinoma (Figure 2)

[TABLE 1 OMITTED]

[FIGURES 1-2 OMITTED]

Several "r flags" that may indicate possible thyroid cancer are listed in Table 2 (79)

Physical Examination

Nodules are ofttimes discovered by the patient as a visible clear or they are discovered incidentally during a physical examination. Thyroid nodules may be undisturbed or nodular, diffuse or localized, pliable or hard, mobile or fixed, and painful or nontender. While palpation is the clinically relevant order of examining the thyroid gland, it can be insensitive and inaccurate depending upon the skill of the examiner. (69) Nodules that are les than 1 cm in diameter are not usually palpable unles they are located in the anterior portion of the thyroid lobe. Larger lesions are easier to palpate, with the exception of for those that lie discerning within the gland. Regardless, about undivided half of all nodules lay opened by ultrasonography escape detection in succession clinical examination. (9) In addition to palpation of the thyroid gland, a thorough examination of the lymph glands in the head and neck should be performed. Indicators of thyroid malignancy include the following: a hard, fixed lesion; lymphadenopathy in the cervical region; nodule greater than 4 cm; or hoarseness.

Diagnosis

In 1996 the Thyroid Nodule Task Force of the American Association of Clinical Endocrinologists and the American society of Endocrinology created a practice guideline for patients with thyroid nodules. (10) It was discloseed to formulate a clear, concise approach to the evaluation of thyroid nodules and "to increase the understanding of the diagnosis and treatment of thyroid nodules for physicians and patients." (10) Figure 3 (11) is a diagnostic algorithm for the evaluation of a thyroid nodule.

[FIGURE 3 OMITTED]

LABORATORY EVALUATION

A sensitive thyroid-stimulating hormone (TSH) proof should be drawn on patients to determine those with thyrotoxicosis or hypothyroidism (Figure 4) When the TSH flush is normal, aspiration should be considered. When this even is low, a diagnosis of hyperthyroidism should be considered; when the value is elevated, hypothyroidism is a possibility. Serum calcitonin should be measured in anyone with a family history of medullary thyroid carcinoma. Thyroid function exhibitions should not be used to distinguish whether a thyroid nodule is benign or malignant. T4 antithyroid peroxidase antibodies, and thyroglobulin exhibitions are not helpful in determining whether a thyroid nodule is benign or malignant, nevertheless they may be helpful in the diagnosis of Graves' disease or Hashimoto's thyroiditis.