2025 – PAGE 77 – ENDOCRINOLOGY
THYROGLOSSAL DUCT CYST
A thyroglossal duct cyst is a midline lesion on anterior neck. As many as half of all thyroglossal duct cysts can get infected, which then increases the chances of recurrence. Therefore, the treatment of choice is surgical excision IF the thyroid is intact. For the exam, if they describe a midline cystic lesion, choose this as the diagnosis. Diagnose by ultrasound and do a thyroid scan to ensure the thyroid gland is intact because sometimes the only functioning thyroid tissue may be within the cyst itself. If the thyroid gland is okay, remove the cyst!
PEARL: Don’t get confused with a RANULA, which is a painless, mucous and CYSTIC mass usually near the inner lips or under the tongue. This might be midline, will have clear contents and should be treated by removal.
THYROID NODULES
Thyroid nodules are more likely to be malignant in kids than in adults, so must be worked up. Get thyroid function tests (low TSH suggest possibility of a hyperfunctioning “hot” nodule) and an ultrasound to better assess size, location, and characteristics. If ultrasound is not a choice, get radioactive imaging, which will help distinguish between hot and cold nodules. Fine needle aspiration is then the usual method of choice to diagnose lesions that are still suspicious. COLD NODULE = INACTIVE TISSUE = BAD!
HYPERTHYROIDISM
GRAVES DISEASE = HYPERthyroidism
Graves disease (AKA Graves’ Disease) causes hyperthyroidism due to the presence of “thyroid-stimulating immunoglobulin.” Signs/symptoms may include an infiltrative ophthalmopathy, emotional lability, weight loss, tachycardia, heat intolerance, and possible LID LAG. TSH should be VERY low/absent! Radioactive Iodine Uptake is HIGH in Grave’s since it needs lots of iodine to make all of the THYROXINE being released. Treatment options include methimazole, iodine ablation, a beta-blocker (propranolol for symptomatic relief), thyroidectomy and PTU (propylthiouracil). Methimazole and PTU inhibit T4 production (not secretion). GOITERS in patients with hyperthyroidism are cells that are FULL of thyroid hormone, so it can take months to become euthyroid.
PEARL: Some of the symptoms of hyperthyroidism may be disguised as “hyperactivity, disorganized thinking, and trouble sleeping.”
PEARL: If a patient has a goiter, more information is needed to differentiate between hypothyroidism and hyperthyroidism.
MNEMONIC: PTU can be hepatotoxic, so it is NOT a first-line agent. P-T-U = Potentially Toxic, UGH!
MNEMONIC: If you look at the letters for GravEs DisEasE versus HashimOtO’s ThyrOiditis, you’ll notice that Grave’s Disease has plenty of E’s in it, like hypErthyroidism, while Hashimoto’s doesn’t have a single E in it! Just the O’s, like hypOthyroidism.
NEONATAL THYROTOXICOSIS (AKA NEONATAL GRAVES DISEASE)
Neonatal Thyrotoxicosis (AKA Neonatal Graves Disease) occurs when maternal thyroid-stimulating antibodies cross over and cause symptoms in the immediate newborn period. Symptoms include tremors, tachycardia, and SVT. This occurs in fewer than 10% of babies born to moms with Graves Disease. For a pregnant woman with Graves Disease, give PTU during the first trimester of Pregnancy when the greatest development is taking place since methimazole is a teratogen. Then, once that critical phase is over, switch to methimazole to avoid the potential hepatotoxicity of PTU.
PEARL: If a patient has symptoms that are suggestive of both Neonatal Thyrotoxicosis and an Inborn Error of Metabolism (IEM), look at the age of onset! IEMs do not result in symptoms within the immediate newborn period.