Thyroid nodules/cancer 178 Flashcards
What are the major signs of hyperthyroidism?
hyperactivity, tachycardia,hyperthermia, increased perspiration, hyperreflexia, muscle weakness, tremor, weight loss, eyelid retraction, exophthalmos (Graves’ disease), diffuse or nodular goiter
What are the major signs of hypothyroidism?
lethargy, bradycardia, cold intolerance, dry skin, hyporeflexia, myxedema, hoarseness, weight gain
What are the symptoms of intrauterine/neonatal hyperthyroidism?
mental retardation
advanced bone age
What are the symptoms of intrauterine/neonatal hypothyroidism?
mental retardation, neurologic deficits, retarded bone age/growth
What are the symptoms of hyperthyroidism?
nervousness, weakness, palpitation, increased appetite, irregular menses
What are the symptoms of hypothyroidism?
fatigue, sleepiness, depression, constipation, decreased appetite, irregular menses
What are the lab findings (TSH, T4, T3) of primary hyperthyroidism? Central/secondary?
primary: high T4, high T3, low TSH
central/secondary: high T4, high T3, high TSH
What are the lab findings (TSH, T4, T3) of primary hypothyroidism? Central/secondary?
primary: low T4, low T3, high TSH
central/secondary: low T4, low T3, low TSH
What are the lab findings (T4, T3, TSH) of primary thyrotoxicosis?
low TSH, high T4, high T3
What are the signs of endocrine ophthalmopathy?
soft tissue involvement, proptosis, extraocular muscle involvement, corneal lesions, lagophthalmos, compressed optic nerve
How can pregnancy lead to hyperthyroidism?
hCG crossreacts with the TSH receptors, resulting in mildly elevated free thyroid hormones
What is the mechanism of thionamides?
they inhibit the organification of iodide and the coupling reaction by blocking thyroid peroxidase
also decreases conversion of T4 into T3
What medications can be used to treat hyperthyroidism?
thionamides (propylthiouracil and methimazole)
What are the side effects of thionamides?
thionamide-induced agranulocytosis
PTU associated with hepatotoxicity
methimazole associated with teratogenecity in early pregnancy
What is the mechanism of iodine radiotherapy for hyperthyroidism?
the iodine delivers beta-irradiation to the thyroid tissue
What is the major complication associated with surgical thyroidectomy?
hypoparathyroidism
What is the treatment for hypothyroidism?
levothyroxine and regular monitoring
What is subacute/DeQuervain’s thyroiditis?
a form of thyroiditis that is often preceded by a URI that presents with fever, malaise, and tenderness to palpation
starts with thyrotoxicosis followed by a hypothyroid phase that may eventually normalize
What is the mechanism of postpartum thyroiditis?
pregnancy leads to generalized immunosuppression, which can cause a rebound of thyroid antibodies after delivery
can cause transient hyper- or hypothyroidism
What are the risk factors for development of thyroid nodules?
iodine deficiency and radiation, older age
What are the major associations with MEN2A?
medullary thyroid carcinoma, parathyroid adenomas, pheochromocytoma
What are the major associations with MEN2B?
mucocutaneous ganglioneuromas, marfanoid habitus
What are the etiologies of thyroiditis? How are they treated?
etiologies: autoimmune, subacute, postpartum
treatment: betablockers during the hyperthyroid phase, levothyroxine during the hypothyroid phase (may be needed long term)
How do you evaluate patients presenting with thyroid nodules?
TSH followed by radioiodine scan if hyperthyroid; ultrasound
