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Thyroid Nodule

A 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