Acromegaly and Prolactinoma - SRS Flashcards
Why would a female with acromegaly have abnormal menstrual cycles?
!!TQ here!!
Acromegaly may be accompanied by amenorrhea and galactorrhea because…
- GH stimulation of the prolactin receptor (both are cytokine receptors)
- GH may cosecrete prolactin (mammosomatotroph adenoma)
- Tumor may press on the pituitary stalk and block transit of dopamine
- Impaired gonadotropin secretion by the pituitary (d/t increased prolactin suppression)
What are the causes of a positive Tinel’s sign?
Which one would apply in this class?
Mnenonic is “Median Trap”
- Myxedema
- Edema
- Diabetes
- Infiltration
- Amyloid
- Neoplasms
- Trauma
- Acromegaly
- Pregnancy
What type of headache is worse with coughing, associated with nausea and worse on arising?
Those caused by a brain tumor
Why the acanthosis nigricans and skin tags in patients with acromegaly?
D/t insulin resistance and excess IGF-1
When testing for acromegaly we do what challenge?
What would a positive result be?
What would you do next?
75g glucose challenge, check glucose and GH levels every 30 minutes post administration - positive if this fails to suppress GH to less than 1 ng/mL.
THEN, if positive order an MRI.
What are the causes of acromegaly?
3
- Microadenoma with somatotroph mutation
- Macroadenoma
- Ectopic GH or GHRH production
What are some examples of cancers that cause ectopic production of GH or GHRH?
6
- Carcinoid
- Pancreas
- Lung
- Ovary
- Breast
- Lymphoma
Acromegaly and giantism may be associated with what syndromes?
- MEN 1 ( 3 Ps with hypercalcemia, peptic ulcer, or hypoglycemia).
- Carney complex ( mutation in tumor suppressor gene for protein kinase A).
- MuCune-Albright syndrome (Polyostotic fibrous dysplasia, café au lait, endocrine hyperfunction).
What does this child who is at risk of gigantism have?
McCune Albright Syndrome - Polyostotic fibrous dysplasia, café au lait, endocrine hyperfunction
What are 3 associated complication types of a GH secreting adenoma?
- Pressure effects (headache, visual alterations, etc).
- Additional hormone production (cosecretion of prolactin).
- Interference with other hormones (decreased ACTH, TSH, etc).
List for me 8 comorbidities associated with Acromegaly.
- Sleep apnea
- Hypertension
- Diabetes
- Cardiomyopathy
- Colon polyps
- Degenerative joint disease
- Thyroid nodules
- Premature mortality
Based on the comorbidities associated with a GH adenoma, what are three tests you should consider doing?
List why for each.
ECHO - test for cardiomyopathy
Colonoscopy - Colon Polyps common
Vertebral Xray - degenerative joint disease seen here
What are some options for pharm tx of GH adenomas?
7 options, 6 of which are on our drug list
- Bromocriptine - DA agonist
- Cabergoline - DA agonist
- Octreotide - SST analogue
- Lanreotide - SST analogue
- Pasireotide - SST analogue
- Pegvisomat - GH receptor antagonist
Apart from the pharm tx, what other options are there to deal with an adenoma?
- Surgery
- Radiation
If you send a pt to undergo transphenoidal surgery for removal of a GH adenoma, and they only find hyperplasia, what should you do?
Look for an ectopic source of either GH or GHRH
Which of the lung cancers is most likely to secrete GHRH?
Small cell (AKA Oat cell)
What should be done prior to surgery for a GH producing adenoma?
GHRH assay to look for possible ectopic production
How should you follow a patients progress after tx of an adenoma?
Monitor GH and IGF-1.
If suspicous of a recurrence, do a Glucose challenge test.
What are the goals of therapy in a GH secreting adenoma?
Reduced IGF-1
Glucose suppression of GH to under 1 ng/mL
Why would a female patient with a prolactinoma have dyspareumia, hirsutism and acne?
!! TQ here !!
Decreased estrogen leads to decreased sex hormone binding globulin (SHBG) and this leads to increased free testosterone and DHEAS. This leads to the hirsutism, acne and dyspareunia.
Causes of hyperprolactinemia can be grouped into:
- Endocrine
- Drugs
- Other
What are the Endocrine causes? 4
- Pituitary adenoma
- Hypothalamic disease
- hypothyroidism
- pregnancy
Causes of hyperprolactinemia can be grouped into:
- Endocrine
- Drugs
- Other
What are the Drug causes? 7 with three bolds
- Metoclopramide
- SSRI
- opiates
- Verapamil (and other anti-HTN)
- Estrogen
- Cimetadine
- Protease inhibitors
Causes of hyperprolactinemia can be grouped into:
- Endocrine
- Drugs
- Other
What are the “Other” causes?
- Cirrhosis
- Exercise
- macroprolactinemia (IgG binding)
- Nipple stimulation
- REM sleep
- Renal Failure
- SLE
- Stress
Darrow gave us a mnemonic for the causes of hyperprolactinemia. What was it?
HIGH PROLACTINS
Hypertensive meds (verapamil, reserpine, alpha methyldopa)
Infiltrative disease (sarcoid, hemochromatosis, etc); Infection (TB, Histo, etc)
Growth hormone (acromegaly)
Hypothyroidism(TRH) ; H2 blockers(cimetidine, ranitidine)
Pregnant/Postpartum; PIs; macroProlactinemia
Renal failure; Reglan (metoclopramide and dopamine inhibitors)
Oral contraceptives (estrogen); Opiates
Liver diseases (cirrhosis)
Adenoma of pituitary; empty sella
Craniopharyngioma
Tranquilizers (including risperidone); Tricyclics and SSRIs; Trauma; Tumor
Idiopathic (look for macroprolactinemia – 10% of hyperprolactinemic patients)
Nipple and chest wall stimulation (zoster)
Stress; Sleep; Seizures; Surgery; SSRIs; SLE; multiple Sclerosis; Sexercise
What level of prolactin would be found with a prolactinoma?
Generally over 200 ng/mL
If 20 - 100, would indicate a different cause.
What would you expect to see in a male with prolactinoma?
- Loss of libido
- Impotence
- Bitemporal hemianopsia
What do you suspect if a patient with a high level (>200 ng/mL) of prolactin and a negative MRI has no symptoms?
Macroprolactinemia - large prolactin molecule
If you find a macroadenoma on MRI what should you do?
Screen for other pituitary insufficiencies
What are the treatment options for hyperprolactinemia?
- Bromocriptine
- Cabergoline
- Surgery
- Radiation
What is postpartum cardiomyopathy related to?
Abnormal prolactin molecules
