Endocrine #7 (Pituitary Adenomas & Clean-Up) Flashcards
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
Treatment for a somatotroph adenoma (both surgical and medical)
-Transsphenoidal resection is treatment of choice
-Octreotide or Lanreotide is used, first line, if surgery not possible. They inhibit GH release.
-Cabergoline or Bromocriptine: dopamine inhibits GH
What is a corticotroph adenoma?
What is this also known as?
ACTH-secreting pituitary adenoma that leads to hypercortisolism (Cushing’s Syndrome)
Cushing’s Disease
Symptoms of a corticotroph adenoma?
Proximal muscle weakness
Weight gain
Osteoporosis
ED
Polyuria
Oligomenorrhea
Headache
Mental changes
How do you differentiate Cushing’s Disease from other causes of Cushing’s Syndrome?
-Increased ACTH + suppression of cortisol on high-dose Dexamethasone suppression test
Where is growth hormone made?
Anterior Pituitary
Symptoms of growth hormone deficiency?
-Short stature
-Growth delays
-Dwarfism
-Fasting hypoglycemia
-Dyslipidemia
-Decreased bone mass
-Decreased cardiac output
What test is done to determine if hypopituitarism is the cause of GH deficiency?
Arginine stimulation test: Pituitary should secrete GH in response to arginine
There are many causes of hyperprolactinemia. What are some of them?
-Prolactinoma (MCC)
-Hypothyroidism (increased TRH stimulates prolactin)
-Dopamine Antagonists (Risperidone, Haloperidol)
-SSRI’s, TCA’s, Verapamil, Estrogen
-Pregnancy, Stress, Exercise
How does prolactin work with gonadotropin-releasing hormone?
Prolactin inhibits gonadotropin-releasing hormone –> hypogonadism
Symptoms of hyperprolactinemia
-Oligomenorrhea
-Amenorrhea
-Infertility
-Vaginal dryness
-Galactorrhea
-ED, Decreased libido
-Gynecomastia in males
Treatment for hyperprolactinemia
-Discontinue offending drugs
-Dopamine agonists (Cabergoline or Bromocriptine) inhibit prolactin
Hypogonadism is a decrease in either or both of the primary function of the testes (testosterone and sperm production). In primary, there is a decrease in function of the ______ cells. This means there is decreased __________
Leydig
Testosterone synthesis
What diagnostic should be done for hypogonadism?
Morning serum total testosterone: decreased
Normal FSH if primary.
Metabolic syndrome is also known as Syndrome X or Insulin Resistance Syndrome.
What is the key component in this condition?
Explain the pathology of this.
Insulin resistance
Free fatty acids are released which causes and increase in TG’s and glucose production and reduction in insulin sensitivity.
High levels of insulin can cause sodium reabsorption, leading to hypertension.
To be diagnosed with metabolic syndrome, you need 3 of the 5 criteria. Name the 5.
1) Low HDL: < 40 in men and < 50 in women
2) High BP: >135 or > 85 (or on meds for htn)
3) High fasting TG’s: >150 (or on meds)
4) High fasting sugar: >100 (or on meds)
5) High abdominal obesity: waist circumference > 40 in men and > 35 in women
Initial management for metabolic syndrome
-Lifestyle: weight reduction, exercise, activity, diet
Name some medications used for weight loss that can be used in metabolic syndrome.
-Phentermine (only used for 3 months)
-Phentermine/Topiramate (no restriction on usage)
-Lorcaserin: induces satiety
-Orlistat: inhibits fat absorption
Multiple Endocrine Neoplasia I (MEN I) is a rare inherited disorder of 1 or more overactive endocrine gland tumors. Most tumors are benign with this condition. Where are the clinical manifestations with this condition (3 P’s).
Parathyroid: hyperparathyroidism
Pancreatic Tumors: Gastrinomas (ZES), Insulinomas, etc.
Prolactinomas
What labs should you order to screen patients who have MEN I
PTH + Calcium
Gastrin
Prolactin
With multiple endocrine neoplasia II, what are some manifestations you should watch for?
-Medullary Thyroid Carcinoma
-Pheochromocytoma
-Neuroma: mucosal (lips, tongue, eyelids, nasal)
-Marfanoid Habitus (scoliosis, high arched palate, pectus excavatum)
What should you screen in patients you suspect with MEN II?
-Calcitonin
-Epinephrine
-PTH
-Calcium
