Endocrinology Flashcards
(112 cards)
What is the name of the anterior and posterior lobes of the pituitary gland?
- Anterior: Adenohypophysis.
- Posterior: Neurohypophysis
What are the hormones produced from the pituitary gland ?
Anterior:
- Growth Hormone GH
- Prolactin
- Thyroid stimulating hormone TSH
- Adrenocorticotropic hormone ACTH
- Luteinizing hormone LH
- Follicle-stimulating hormone FSH
Posterior:
- Antidiuretic hormone ADH (Vasopressin).
- Oxytocin
What is the cause of amenorrhea in Galactorrhea - amenorrhea syndrome ?
Amenorrhea is caused by inhibition of the hypothalamic release of Gonadotropin- releasing hormone (GnRH) with a decrease in Luteinizing hormone (LH) and follicle - stimulating hormone (FSH) secretion.
What is the most common presentation of Hyperprolactinemia in men?
- Erectile dysfunction
- Decreased libido.
What is the most common functioning pituitary adenomas ?
Prolactinoma.
Name the medications that can cause hyperprolactinemia.
- Drugs that block Dopamine synthesis ( Phenothiazines and Metoclopramide).
- Dopamine- depleting agents (alpha-methyldopa and reserpine).
- Tricyclic antidepressants.
- Narcotics.
- Cocaine.
- SSRIs
- Risperidone.
What os the clinical presentation of hyperprolactinemia ?
In females:
- Galactorrhea.
- Menstrual abnormalities (Amenorrhea/ oligomenorrhea.
- Osteopenia.
- Osteoporosis.
- Infertility
- Gynecomastia.
In males:
- Hypogonadism.
- Erectile dysfunction.
- Decreased libido.
- Infertility
- Gynecomastia.
How to diagnose hyperprolactinemia ?
- Rule out: Pregnancy , lactation, hypothyroidism and meds.
- Prolactin level > 100 ng/mL suggest pituitary adenoma.
- Prolactin level > 100 ng/mL = 1 cm prolactinoma.
- Prolactin level > 200 ng/mL = 2 cm Prolactinoma.
What is the management of Prolactinoma ?
- Cabergoline or Bromocriptine (Dopamine-agonist).
- Cabergoline : less S/E and treats galactorrhea.
- Surgery IF nor responsive to Tx or there is significant compressive neurological effects.
Radiation if both drug therapy and surgery were ineffective.
What is the indication of Pituitary MRI ?
Basal, fasting, morning Prolactin level > 100 -200 mg/L in non pregnant women.
What is the normal level of Prolactin ?
< 20 mg/L
What is the name of the syndrome caused by excessive secretion of broth hormone?
Acromegaly
Gigantism in children
What is the most common cause of death in acromegaly ?
Cardiovascular mortality.
What are the clinical findings of acromegaly ?
- Skeletal and soft tissue changes.
- Enlargement of hands and feet.
- Coarsening of facial features.
- Thickened skin folds.
- Enlarged nose and mandible.
- Deeper voice.
- Increased sweating.
- OSA.
- Enlarged internal organs.
- Interstitial edema
- Osteoarthritis.
- Entrapment neuropathy.
- Menstrual problems.
- cardiac anomalies.
- Metabolic changes (DM, Impaired glucose intolerance.
- HTN
- H/A and visual fiels loss
- Proliferated articular cartilage causing sever joint disease.
How to diagnose acromegaly ?
Initial: High level of Insulin- like Growth Factor IGF-1.
Confirmatory: Give 100g of glucose orally, then measure growth hormone GH, if > 5ng/mL) then POSITIVE.
“normally glucose suppress level of GH.
Imaging: to localize tumor AFTER GH excess is documented biochemically. MRI better than CT.
What is the primary treatment of acromegaly ?
Transsphenoidal surgery.
What is the first and second line medical treatment of acromegaly ?
First line:
Somatostatin analogues :
- Octreotide (The best)
- Inareotide
Second line:
Pegvisomant (a growth hormone analogue ).
How does Pegvisomant (the second line treatment of acromegaly) works ?
It is a growth hormone analogue which antagonizes endogenic GH by blocking peripheral GH binding to its receptor in the liver.
What is the side effects of Octreotide (the first line treatment of acromegaly)?
Cholestasis, leading to cholecystitis.
What are the complications of acromegaly ?
- Tumor pressuring on surrounding structures.
- Invasion of tumor into brain or sinuses.
- Cardiac failure.
- Diabetes mellitus
- cord compression
- visual field defect.
What is the most common cause of death in acromegaly ?
Cardiac failure.
What are the condition that can lead to hypopituitarism ?
- large pituitary tumors or cysts.
- Hypothalamic tumors (craniopharyngiomas, meningiomas, gliomas).
- Pituitary apoplexy syndrome.
- Inflammatory diseases:
- Granulomatous diseases (Sarcoidosis, TB, syphilis.
- Eosinophilic granuloma
- Autoimmune lymphocytic hypophysitis\
- Trauma
- Radiation
- Surgery
- Infections.
- Vascular diseases: e.g (Sheehan postpartum necrosis)
- Infiltrative disease: e.g ( hemochromatosis and amyloidosis)
- Stroke
What is hypopituitarism ?
It is partial or complete loss of anterior function that results from any lesion which destroys the pituitary or hypothalamus or which interferes with the delivery of releasing and inhibiting factors to the anterior hypothalamus.
What is the most common cause of Panhypopituitarism ?
Pituitary adenomas.