Endocrine Flashcards
Thyroid nodule >1 cm:
Hyperfunctioning. Next step?
Skip the FNA, obtain nuclear thyroid scintigraphy
Thyroid nodule >1 cm:
Cold nodule. Next step?
FNA. Thyroid cancer occurs in about 25% of nodules in children and adolescent (vs. 5% in adults), usually papillary.
MEN 2A and 2B - phenotype?
medullary thyroid carcinoma + pheochromocytoma + hyperPTH
in 2B: marfanoid body habits, multiple neuromas
Amiodarone-induced thyrotoxicosis:
Type 1 associated with ___ and Dopplers show __. Treat with?
Type associated with ___ and Dopplers show ___. Treat with?
Type 1 - underlying goiter or latent Graves, and increased vascularity. Treat with methimazole.
Type 2 - normal thyroid, no increased vascularity on Doppler. Treat with prednisone.
Why thyroid scintigraphy with radioactive iodine shouldn’t be done in patients on amiodarone?
Amiodarone has a very high iodine content, which results in high serum iodine levels. This iodine competes with the radioactive isotope used for the test (123I or 131I) resulting in very low radioactive iodine uptake (<1%) in most patients.
A 9-year-old girl is evaluated for concerns about her lack of growth. The girl has not been outgrowing her clothes, and her sister, who is 2 years younger, is catching up to her in height. She has no significant medical history and takes no medication. A review of systems reveals worsening vision over the past month. She has also been having intermittent headaches at school that her mother attributes to her vision problems. Her adjusted midparental height is at the 60th percentile. Her mother had menarche at 12 years of age, and her father had delayed puberty. Her visual acuity is 20/100 bilaterally.
Possible diagnosis?
The girl in this vignette has growth failure secondary to a craniopharyngioma. Brain magnetic resonance imaging (MRI) is the test most likely to reveal the diagnosis. Poor linear growth, headaches, and vision problems are common presenting symptoms of craniopharyngioma. Growth hormone deficiency is the most common anterior pituitary hormone deficiency at the time of diagnosis, manifesting as growth problems. Other pituitary hormone deficiencies may also be present and can contribute to abnormal growth. The other symptoms of craniopharyngioma are caused by increased intracranial pressure and mass effect on the optic chiasm.
Craniopharyngioma is the most common suprasellar tumor in childhood. These tumors originate from the remnants of Rathke’s pouch and are benign, but they can cause significant problems because of their location and mass effect. The peak incidence in childhood is between 5 and 14 years of age. The standard imaging modality is MRI with and without contrast. Craniopharyngioma appears as a cystic mass on MRI. Characteristic intratumoral calcifications can be seen on computed tomography. Treatment is associated with significant morbidity, specifically panhypopituitarism, diabetes insipidus, hypothalamic obesity, and vision loss.
Growth evaluation, if crossing height percentiles after age 3 years and outside of the peripubertal period?
In other words, when height velocity is decreased with relative preservation of weight, suspect __.
When height velocity is decreased with relative preservation of weight, an endocrine or genetic disorder should be suspected. These endocrine disorders include growth hormone deficiency, hypothyroidism, and glucocorticoid excess (Cushing syndrome). In addition to declining growth velocity, Cushing syndrome is usually also associated with marked weight gain. Common genetic disorders associated with declining growth velocity include Turner syndrome and Noonan syndrome.
3 tests for Cushing’s dx?
Late night salivary cortisol
Overnight 1 mg dexamethasone test
24 hr urinary free cortisol
Thyrotoxicosis management?
β-adrenergic blockers (esmolol infusion), antithyroid drug therapy, intravenous glucocorticoids, and potassium iodide. Plasmapheresis and emergent thyroidectomy are utilized in patients who cannot be sufficiently managed with medical therapy alone.
