Goiter%20nontoxic%20(simple)--%20diffuse%20-and-%20multinodular Diagnosis
Diagnosis
- Diagnosis of exclusion to rule out goiter due to hypothyroidism, hyperthyroidism, autoimmune thyroiditis, invasive fibrous thyroiditis, medications and iodine deficiency or excess
History
- Cosmetic complaints (disfigurement due to enlarged goiter), obstructive complaints, growth rate and family history
Physical Examination
- Inspect neck (check size, nodules and texture of goiter), detect obstructive signs (stridor, Pemberton’s sign, plethora, etc)
- Nontoxic multinodular goiter: Multiple, distorted nodules of varying sizes
- Diffuse nontoxic goiter: Symmetrical, enlarged, non-tender, soft gland without nodules
- A retrosternal goiter may not be evident on physical exam
Laboratory Tests
Thyroid Function Tests
- Measure serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels [measure serum free triiodothyronine (FT3) levels if FT4 is normal and in nodular goiter] to exclude hyperthyroidism and hypothyroidism
- Euthyroid state (normal serum FT3 and FT4 levels) may suggest diagnosis of goiter (simple/nontoxic)
- TSH suppression may develop due to increasing goiter size
- FT3 toxicosis may occur in multinodular goiter
- Measure: Thyroid peroxidase (TPO) antibodies, thyroglobulin antibodies and TSH receptors antibodies to exclude autoimmune thyroid diseases
Fine Needle Aspiration Cytology (FNAC)
- Performed to rule out malignancy in cases of suspicious nodules
- Indicated if the patient has a history of rapid growth, pain, or tenderness, also if there is unusual firmness in one region of the goiter; or sonographically detected nodules with indeterminate or suspicious sonographic features
- May be performed with ultrasound guidance in cases of nonpalpable nodules with diameter of ≥1 cm
Pulmonary Function Tests
- Performed to determine the degree of airway obstruction
Imaging
Thyroid Ultrasound
- Preferred and most useful imaging modality to guide disease management and treatment of nodular goiter
- Gold standard for measuring thyroid size, identifying the structure and evaluating diffuse changes in the thyroid gland
- Recommended in patients with physical examination revealing thyroid asymmetry, focal firm consistency or tenderness, rapid growth of goiter, and goiter with normal TSH level and negative TPO antibodies
- Provides a measure of goiter growth rate over time and posttreatment
- Determines extent of nodularity
Thyroid Scintigraphy
- Visualizes goiter, determines its inherent properties; identifies hot and cold nodules
- Recommended in patients with solitary thyroid nodule or multinodular goiter with low TSH levels
X-ray of the Neck and Upper Mediastinum
- Used to determine the presence of tracheal compression
Computed Tomography (CT)/Magnetic Resonance Imaging (MRI)
- Perform CT/MRI (to evaluate the anatomy of the goiter and the extent of substernal extension), if substernal goiters are suspected
- Pemberton’s sign, obstructive signs and symptoms suggest substernal goiter
- Substernal goiter may obstruct thoracic inlet and compress trachea