The problems facing the clinician when confronted by a patient with a nodular goiter or thyroid nodule are whether the lesion is symptomatic and whether it is benign or malignant. The differential diagnosis includes benign goiter, intrathyroidal cysts, thyroiditis, benign and malignant tumors, and metastatic tumors to the thyroid. The history should specifically emphasize the duration of swelling, recent growth, local symptoms (dysphagia, pain, or voice changes), and systemic symptoms (hyperthyroidism, hypothyroidism, or those from possible tumors metastatic to the thyroid). The patient's age, sex, place of birth, family history, and history of radiation to the neck are most important. Low-dose therapeutic radiation (6.5–2000 cGy) in infancy or childhood is associated with an increased incidence of thyroid cancer (about 10%) in later life.
A thyroid nodule is more likely to be a cancer in a man than in a woman and in young (under 20 years) and older (over 60 years) patients rather than in others. In certain geographic areas, endemic goiter is common, making benign nodules more common. Thyroid cancer is familial in about 25% of patients with medullary thyroid cancer (familial medullary thyroid cancer, MEN 2a and 2b) and in about 7% of patients with papillary cancer or Hürthle cell cancer. Papillary thyroid cancer occurs more often in patients with Cowden's syndrome, Gardner's syndrome, or Carney's syndrome.
The clinician must systematically palpate the thyroid to determine whether there is a solitary thyroid nodule or if it is a multinodular gland and whether there are palpable lymph nodes. A solitary hard thyroid nodule is likely to be malignant, whereas most multinodular goiters are benign.
In many patients, the possibility of cancer is difficult to exclude without microscopic examination of the gland itself. Percutaneous needle biopsy is the most cost-effective diagnostic test for most patients and has replaced radioiodine scanning.
Evaluation schema for an indeterminate thyroid nodule. Important issues that can change the evaluation include family history suggestive of thyroid carcinoma syndrome or a personal history of radiation exposure.
Board Review Questions
1. Choose the one best response to this question.
Which of the following is the most accurate statement concerning the accuracy of FNA in thyroid nodules?
A. false positive rate of 5%
B. false negative rate of 15%
C. use of ultrasound can decrease the rate of unsatisfactory results
D. FNA findings classified as inconclusive have a malignancy rate of 15%
E. FNA diagnosis of follicular neoplasm without atypia is malignant in 20%
2. Choose the one best response to this question.
Fine needle aspiration (FNA) cytology of a thyroid Hurthle cell neoplasm will most likely show which of the following reports?
B. benign nonneoplastic
3. Choose the one best response to this question.
Which of the following ultrasound findings are most suggestive of malignancy in a 55-year-old male with risk factors and a nonpalpable thyroid lesion?
1. The correct answer is C. use of ultrasound can decrease the rate of unsatisfactory results.
2. The correct answer is C. inconclusive.
3. The correct answer is B. hypoechoic.
Read more about Thyroid Nodules on AccessSurgery in the Textbook of Surgical Oncology.