Mehl. Thyroid in pediatrics 03-03 (1) Flashcards
Thyroglossal duct cyst. definition?
benign, painless, midline neck mass in a school-age kid that arises from a persistent thyroglossal duct (i.e., the embryologic remnant of the thyroid gland’s descent from the base of the tongue to its final position in the neck).
benign, painless, midline neck mass in a school-age kid that arises from a persistent thyroglossal duct (i.e., the embryologic remnant of the thyroid gland’s descent from the base of the tongue to its final position in the neck).???
Thyroglossal duct cyst
Thyroglossal duct cyst.
2/3 of Qs will give a painless midline neck lump that moves upwards with swallowing or protrusion of the tongue (due to its attachment to the hyoid bone and/or the base of the tongue).
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Thyroglossal duct cyst.
1/3 of Qs won’t mention the buzzy upward movement with swallowing or protrusion of the tongue; instead, it will just say a kid has a painless midline neck mass just inferior to the hyoid bone that demonstrates 99Tc uptake.
Lingual thyroid. definition?
presence of ectopic thyroid tissue located at the base of the tongue due to failure of the thyroid gland to descend from the foramen cecum.
Lingual thyroid.
Obscure cause of hypothyroidism that shows up on an offline NBME.
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Lingual thyroid.
This ectopic tissue may be the only functioning thyroid tissue in the body, resulting in hypothyroidism.
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The USMLE Q will say a kid has hypothyroidism + a midline neck lump located high in the neck. They say nothing about protrusion of the tongue or uptake into the mass. Dx?
Lingual thyroid.
Lingual thyroid. What non-thyroid CP can be?
Can sometimes cause dysphagia (trouble swallowing), dysphonia (voice changes), or dyspnea (difficulty breathing).
Cretinism. aka?
congenital hypothyroidism
Cretinism. causes worldwide?
Most common causes are iodine deficiency in the mother during pregnancy (worldwide)
Cretinism. cause in western countries?
fetal thyroid dysgenesis.
Cretinism. CP?
Leads to mental retardation (poor myelin sheath development), impaired bone growth, hypotonia, macroglossia, and protuberant abdomen (due to umbilical hernia; can be confused with kwashiorkor, which is protein-calorie malnutrition causing ascites).
Cretinism. how screened, test?
Screened for at birth using the heel-prick test to prevent exacerbation
heel prick tai iduria i kulna ir paima kraujo megini ir tiria 9 ligas kazkokias
TBG deficiency.
The USMLE does not expect you to know about some obscure condition called thyroid-binding globulin deficiency. The reason they ask about this is because the role of TBG on thyroid hormones in pregnancy is exceedingly high-yield, so if you know the reasoning/mechanism behind the latter, you can easily infer what would be seen in TBG deficiency (i.e., the inverse).
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TBG deficiency. arrows?
normal TSH, normal T3, normal free T4, decr. total T4.
TBG deficiency.
In pregnancy, since TBG is high, this ultimately results in high total T4 despite a normal free T4. So the student can easily infer, “Well, if our TBG merely is low, rather than high, then total T4 must be low while free is same. Sort of like pregnancy but just the opposite direction.”
nu tai TBG low, total T4 low, free T4 normal.
