A 30-year-old woman comes to the office due to a nodule in the right lobe of the thyroid gland. The nodule was discovered incidentally on a CT scan of the neck performed 2 weeks ago to evaluate neck pain following a motor vehicle collision. The patient feels well and has experienced no weight change, temperature intolerance, hair or skin changes, or menstrual irregularities. She has no chronic medical problems, takes no prescription medications, and has no history of radiation exposure. Family history is negative for thyroid cancer. The patient does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 120/80 mm Hg and pulse is 72/min. Thyroid examination reveals a palpable, firm, 2-cm nodule on the right lobe. Neck lymph nodes are not enlarged. The remainder of the physical examination is normal.
Laboratory results are as follows:
Ultrasonography of the thyroid gland shows a solid right lobe hyperechoic nodule measuring 2.3×1.6×1.2 cm with no evidence of microcalcification or internal vascularity. Which of the following is the best next step in evaluation of this patient?

Question

A 30-year-old woman comes to the office due to a nodule in the right lobe of the thyroid gland.  The nodule was discovered incidentally on a CT scan of the neck performed 2 weeks ago to evaluate neck pain following a motor vehicle collision.  The patient feels well and has experienced no weight change, temperature intolerance, hair or skin changes, or menstrual irregularities.  She has no chronic medical problems, takes no prescription medications, and has no history of radiation exposure.  Family history is negative for thyroid cancer.  The patient does not use tobacco, alcohol, or illicit drugs.
Blood pressure is 120/80 mm Hg and pulse is 72/min.  Thyroid examination reveals a palpable, firm, 2-cm nodule on the right lobe.  Neck lymph nodes are not enlarged.  The remainder of the physical examination is normal.
Laboratory results are as follows:
 Ultrasonography of the thyroid gland shows a solid right lobe hyperechoic nodule measuring 2.3×1.6×1.2 cm with no evidence of microcalcification or internal vascularity.  Which of the following is the best next step in evaluation of this patient?

Quizplus · Accepted Answer

11ec193a_97ab_a9e5_853d_a9b5f1449849_MD0002_00 The initial evaluation of thyroid nodules includes a serum TSH assay and thyroid ultrasound to assess the risk of malignancy. This patient has biochemical evidence of subclinical hyperthyroidism (ie, suppressed TSH, normal or elevated thyroid hormone levels), suggesting that she may have a hyperfunctioning nodule, which is rarely malignant. She should therefore undergo thyroid scintigraphy (preferably with iodine-123). Hyperfunctioning ("hot") nodules are managed with respect to the hyperthyroid state (eg, symptom control, radioactive iodine, resection), but fine-needle aspiration (FNA) is not necessary (Choice A). Hypofunctioning ("cold") or indeterminate nodules have a higher malignancy risk and may require FNA based on size, ultrasound findings, and patient characteristics: High-risk findings on ultrasound include microcalcifications, increased vascularity, hypoechoic appearance, elongated shape, and indistinct or irregular nodule margins. FNA is indicated in such nodules ≥1 cm.Low-risk nodules on ultrasound (eg, isoechoic, hyperechoic, partially cystic, spongiform) are monitored and biopsied if they grow to ≥1.5-2 cm.Purely cystic nodules are almost always benign and do not require FNA.High-risk patient characteristics include a personal or first-degree family history of thyroid cancer, history of radiation exposure in childhood, rapid nodule growth, and cervical lymphadenopathy. FNA should be considered for any size of nodule in this population. High-risk findings on ultrasound include microcalcifications, increased vascularity, hypoechoic appearance, elongated shape, and indistinct or irregular nodule margins. FNA is indicated in such nodules ≥1 cm. High-risk findings on ultrasound include microcalcifications, increased vascularity, hypoechoic appearance, elongated shape, and indistinct or irregular nodule margins. FNA is indicated in such nodules ≥1 cm. Low-risk nodules on ultrasound (eg, isoechoic, hyperechoic, partially cystic, spongiform) are monitored and biopsied if they grow to ≥1.5-2 cm. Low-risk nodules on ultrasound (eg, isoechoic, hyperechoic, partially cystic, spongiform) are monitored and biopsied if they grow to ≥1.5-2 cm. Purely cystic nodules are almost always benign and do not require FNA. Purely cystic nodules are almost always benign and do not require FNA. High-risk patient characteristics include a personal or first-degree family history of thyroid cancer, history of radiation exposure in childhood, rapid nodule growth, and cervical lymphadenopathy. FNA should be considered for any size of nodule in this population. High-risk patient characteristics include a personal or first-degree family history of thyroid cancer, history of radiation exposure in childhood, rapid nodule growth, and cervical lymphadenopathy. FNA should be considered for any size of nodule in this population. (Choice B) Subclinical hyperthyroidism from nodular disease usually worsens progressively over time. This patient has a large nodule with suppressed TSH, and the TSH will not likely normalize in 3-4 weeks. (Choice C) Anti-thyroid peroxidase antibodies are associated with chronic lymphocytic (Hashimoto) thyroiditis and related disorders (eg, silent and postpartum thyroiditis). Although these conditions can cause a transient hyperthyroid state, they are associated with diffuse, rather than nodular, thyroid enlargement. (Choice D) Serum calcitonin, which is elevated in medullary thyroid cancer and C-cell hyperplasia, is useful for evaluating patients with suspected medullary thyroid cancer. However, routine measurement in patients with thyroid nodules is not recommended due to high false-positive rates. Educational objective: The initial evaluation of thyroid nodules includes a serum TSH assay and thyroid ultrasound. Most patients with normal or elevated TSH should undergo fine-needle aspiration of the nodule for cytologic assessment. Patients with a suppressed TSH should undergo thyroid scintigraphy. Hyperfunctioning nodules are rarely malignant and do not usually require fine-needle aspiration. __________ References: New guidelines for the management of thyroid nodules and differentiated thyroid cancer. (http://www.ncbi.nlm.nih.gov/pubmed/21460787)

A 30-Year-Old Woman Comes to the Office Due to a Nodule