Endocrine #7 (Pituitary Adenomas & Clean-Up) Flashcards
(45 cards)
Gigantism and Acromegaly are both from excessive ________ from a ________
IGF-1 from a pituitary adenoma
What separates the two diagnoses?
Both have severe mortality due to heart, lungs, and cancer problems
Age of onset:
–Gigantism (early): before growth plates closed
–Acromegaly (late): after growth plates closed
What are some symptoms of gigantism
-Tall stature
-Macrocephaly
-Headaches, visual changes
-Front bossing
-Hypopituitarism
What are some symptoms of acromegaly?
-Doughy skin
-Thick, hard nails
-Nasal, lower lip enlargement
-Sweating
-Spaced teeth
-Prognathism (overbite)
-Hypertrichosis: excess hair production
How does glucose normally affect growth hormone?
What diagnostic can be done to diagnose gigantism or acromegaly?
Normally, increased glucose lowers growth hormone
Give glucose and see if it raises growth hormone
What other imaging study should be done on a patient you suspect to have gigantism or acromegaly?
MRI to evaluate the pituitary
Treatment for gigantism or acromegaly
-Adenoma resection
-Somatostain Analogues (Pegvisomant) = (GH antagonist)
On the other hand, dwarfism is
What is the treatment?
-Growth hormone deficiency
-Recombinant GH replacement
A TSH-secreting pituitary adenoma is a rare cause of __________.
For this reason, symptoms include…(remember there is an eye finding too)
-Hyperthyroidism
-Signs of hyperthyroidism: anxiety, heat intolerance, weight loss, fatigue, a-fib, increased metabolic rate, oligomenorrhea
-Diffuse goiter!
-Bitemporal hemianopsia due to compression of optic chiasm.
-Headache
-Mental disturbances
What is seen on diagnostic labs for a TSH-secreting pituitary adenoma?
-Secondary hyperthyroidism profile: increased TSH and increased free T4 (both in the same direction)
What is seen on radioactive iodine uptake scan for a patient with a TSH-secreting pituitary adenoma?
Diffuse increased uptake (like Graves)
Treatment for TSH-secreting pituitary adenoma
-Transsphenoidal surgery
What’s the MC type of pituitary adenoma?
Prolactinoma
What is the function of prolactin?
-Lactation
-Suppression of pregnancy during lactation
-Suppression of gonadotropin-releasing hormone
-Leads to decreased FSH and LH
What inhibits prolactin release as well as GH release?
Dopamine
Manifestations of prolactinoma in women
In men?
Women
-Hypogonadism: amenorrhea, infertility, galactorrhea, local compression (headache and visual changes)
Men
-Hypogonadism: ED, decreased libido, infertility, gynecomastia, local compression
What is one symptom that should be remembered with all pituitary tumors?
Can compress the optic chiasm: leading to bitemporal hemianopsia
What do endocrine studies (labs) show in a prolactinoma?
Increased prolactin
decreased FSH and LH
What is the imaging study of choice to look for pituitary tumors?
MRI
Treatment for a prolactinoma
-Dopamine agonists (Cabergoline, Bromocriptine)
-Transsphenoidal resection if refractory or in women who wish to become pregnant
A somatotroph adenoma is a pituitary adenoma that secretes ________ leading to ______ or _______
Growth-hormone
Gigantism or Acromegaly
Explain the pathophysiology of growth hormone, glucose, and insulin-like growth factor
-Growth hormone (GH) increases glucose
-Increased growth hormone stimulates increased hepatic production of Insulin-like growth factor
Symptoms of a somatotroph adenoma
-DM or glucose intolerance
-Enlargement of soft tissues, cartilage and bone: hands, feet, skull, increased ring, shoe, and hat size
-Headache
-Bitemporal hemianopsia
-Hypertension
-Colonic polyps
What is the initial test of choice for a somatotroph adenoma?
Confirmatory?
What is the imaging study of choice for this?
Initial: Insulin-like growth factor
Confirmatory: oral glucose suppression test - increased growth hormone levels seen in acromegaly (normal response is GH suppression)
MRI