amboss endocrine Flashcards
what is the most common type of thyroid cancer
papillary carcinoma of the thyroid accounts for 80% of thyroid cancers
what is the typical presnetation of papillary thyroid cancer
usually early lymphatic spread is the first finding. there are usually microcalcifications
what is the first step after finding a thyroid nodule
ultrasound
what is the second step after finding a thyroid nodule
measuring TSH.
what to do if thyroid nodule and normal or elevated TSH
regular monitoring in case the tumor grows to more than 1cm and then fine needle aspiration.
what is more likely to be malignant hot or cold nodules
cold nodule s
what is the second most common type of thyroid cancer
follicular
what are the characteristics of follicular thyroid cancer
blood vessel invasion with capsular invasion
usually no lymph node involvement
what does orphan annie nuclei suggest on thyroid biopsy
papillary carcinoma
is lymphoma of thyroid rare or common
very rare and usually arises due to hashimotos thyroiditis
what does psammoma bodies on thyroid biopsy suggest
papillary carcinoma
what are the most likely findings on biopsy of papillary thyroid cancer
psammoma bodies and orphan Annie nuclei
what is the treatment for papillary thyroid cancer
total thyroidectomy; partial resection is possible with tumors <1 cm with no lymph node involvement t
what does high prolactin do to FSH and LH
decreases them. it has an inhibitory effect on GnRH
what is the presentation of hyperprolactinemia
can have milk productive effects, decreases estrogen which causes vaginal atrophy, oligo/amonorrhea, endometrial atrophy. decreased LH/FSH
where are LH and FSH made
pituitary
where is GnRH made
hypothalamus
what is the consequence of GnRH secretion
increases LH and FSH which then stimulate the ovaries to secrete estrogen
what does estrogen do to LH and FSH in a normal system
they inhibit the release as a negative feedback system at the pituitary gland
what happens to estrogen/LH/FSH in primary ovarian failure
there is decreased estrogen production in response to pulsatile GnRH and thus FSH and LH will be HIGH due to the lack of response from the ovaries
what does prolactin do to the GnRH axis
it inhibits the production release of LH and FSH from the pituitary gland and thus reduces estrogen at the ovaries. this is what happens in pituitary adenoma
does a prolactinoma produce galactorrhea in men
Very rarely
what does a proalctinoma usually cause in men
erectile dysfunction
why does a prolactinoma cause erectile dysfunction in men
because the high levels of prolactin will inhibit the release of GnRH from the hypothalamus and thus the release of FSH and LH from the testicles. this will reduce the testosterone levels The resulting manifestations include erectile dysfunction, decreased libido, reduced testicular volume, infertility, gynecomastia, and loss of axillary hair.