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Multinodular Goiter
David L. Steward
History
A 56-year-old woman with a longstanding palpable multinodular goiter is referred by her primary care physician for evaluation. The patient reports a family history of goiter and thyroid surgery but no family history of thyroid cancer. She denies history of radiation exposure. She denies dysphagia, dyspnea, or hoarseness. She denies symptoms of hypothyroidism or hyperthyroidism.
Physical examination reveals multinodular goiter with around 3-cm right-sided and 2-cm left-sided dominant nodules. Vocal cord function is normal. No other masses or evidence of adenopathy are noted.
Differential Diagnosis—Key Points
Multinodular goiter is common and often hereditary. Three main points come up when evaluating a patient with multinodular goiter: (1) Does this represent malignancy? (2) Is there endocrine dysfunction? (3) Is there evidence of compression of surrounding structures as a result of its size?
Test Interpretation
Ultrasound is the best imaging modality for thyroid nodules to assess the presence of non-palpable nodules, for accurate sizing, to identify features suspicious for malignancy, and to guide fine-needle biopsy. Suspicious sono-graphic features of thyroid nodules have an 80% sensitivity for malignancy. Size alone is nondiscriminatory, but larger nodules (>1.5–2 cm) are often biopsied to exclude malignancy even in the absence of suspicious features. In the presence of multiple nodules, biopsy of suspicious nodules should be preferentially performed over benign-appearing larger ones. Often the largest on each side is biopsied along with any sonographically suspicious nodules, requiring biopsy of as many as four nodules to exclude malignancy within a large multinodular gland (see papillary thyroid carcinoma case for further description of ultrasound-guided fine-needle biopsy and cytologic findings).
Screening thyroid-stimulating hormone (TSH) should be done to exclude subclinical hyperthyroidism, which is common in multinodular goiter. If the TSH is low, then follow-up testing of free tri-iodothyronine (T3) and free thyroxine (T4) is necessary to confirm hyper-thyroidism from toxic multinodular goiter.
