When we are trying to investigate the endocrine system for a disease, the followings are true except
the release of many hormones is pulsatile , so a random blood sample is usually useless
many endocrine glands have what is called incidentalomas
many endocrine tumors are difficult to classify as malignant or benign during histopathological examination
if you suspect a hormonal excess then choose a suppression test
endocrinal abnormalities are rarely characterized by loss of normal regulation of hormonal secretion
When dealing with a pituitary tumor, the followings are true except
rarely is a cause of hydrocephalus
may an incidental finding on MRI done for another reason
rarely there is a downward extension and hence may be seen as a nasal polyp
may produce a hypothalamic syndrome by an upward extension
pituitary apoplexy is usually asymptomatic
Surgical treatment is usually considered to be a first line treatment for the following pituitary / hypothalamic tumors ,except
non functioning pituitary macroadenoma
craniopharyngioma
Cushing disease
prolactinoma
acromegally
Causes of Hyperprolactinemia , all are true except
stress
primary hypothyroidism
chronic renal failure
chronic chest well stimulation
treatment with pergolide
Treatment of prolactinomas , all are true except
-treatment with dopamine agonists, is almost always effective in normalizing prolactine level and restoration of gonadal function
after menopause, treatment of microprolactnimoas is only indicated if there was a trouble some galactorrhea, otherwise can be left untreated
trans-sphnenoidal surgery has a success rate approaching 80%
macroprolactnimas may enlarge rapidly during pregnancy and hence bromocyptin should be continued despite pregnancy with close follow up during the whole pregnancy
external irradiation is a useful first line treatment in the majority of patients
Acromegaly, all are true except
although glucose intolerance is seen in 25% of cases yet overt diabetes mellitus is seen only in 10% of cases
there is a 2-3 folds increase in the relative risk of colonic cancer and coronary artery disease
trans-sphenoidal surgery has a high success rate
a dopamine agonist may be used in those with co-existent hyperprolactinemia because it is generally less effective than octreotide
external irradiation has a good rapid action against the tumor
A random blood sample for GH assessment in a suspected deficiency state is useless because it is commonly undetectable , so there are several " tricks " to collect a blood sample for GH assessment , all are true except
Sampling before exercise.
frequent sampling during sleep
sampling 1 hour after going asleep
sampling during an insulin induced hypoglycemia
stimulation with arginine
ACTH stimulation test, all are true except
used in the diagnosis of primary and secondary adrenal insufficiency
the 250 microgram tetracosactrin injection should be given in the early morning
relies on ACTH dependent adrenal atrophy in secondary adrenal failure
normally after 30 minutes the blood cortisol should be above 550 nmol/ L
useually useless in adrenal failure secondary to acute ACTH deficiency
Panhypopituitarism , all are true
there is a striking pallor
GH is usually the earliest hormone to be lost
Coma is multi-factorial and may be due to water intoxication , hypoglycemia or hypothermia
The skin is smooth with a baby like texture
Serum TSH should be measured to assess the optimal T4 replacement dose
Insulin tolerance test, all are true except
used in the assessment of hypothalamic pituitary adrenal axis
contraindicated in ischemic heart disease and epilepsy
the aim of the test is to produce signs of hypoglycemia with a glucose level below 2.2 mmol/ L
we should take serial blood samples of glucose, GH and cortisol
the usual dose used in the test is NPH insulin 0.15 u/kg given subcutaneously
Water deprivation test for a suspected diabetes insipidus , all are true except
it is used in the diagnosis of diabetes insipidus ( DI )and to differentiate between cranial and nephrogenic DI.
there is should be no coffee, tea or smoking on the test day
The test should be stopped if the patient loses 3% of his body weight
when trying to differentiate DI from compulsive water drinking, DDAVP is useful
if the initial urinary osmilality is 700 mosl/ kg the nthe test should be stopped and DI is excluded
Hyperthyroidism , all are true except
the commonest cause is Grave's disease
if there is prominent anorexia then a malignant cause should be suspected
vitilligo and lymphadenopathy goes more with Grave's disease than other etiologies
apathy and osteoporosis are mainly seen in elderly patients
pruritis, palmar erythema and spider nevi are more suggestive of an associated chronic active hepatitis
Non specific biochemical abnormalities in thurotoxicosis , all are true except
raised alkaline phosphatase
raised ALT and AST
hypercalcemia is usually seen in 50 % of cases
glycosuria
raised gamma GT in the absence of enzyme-inducing drugs or alcoholism
Treatment of thyrotoxicosis , all are true except
following successful treatment with carbimazole, up 50% will relapse following drug stoppage
subtotal thyroidectomy is contraindicated in those with previous thyroid surgery
radi-iodine is contraindicated in pregnancy
following subtotal thyroidectomy , up to 10% will develop permanent hypocalcaemia
following treatment with radio-iodine, up to 80% will develop permanent hypothyroidism after 15 years
Subacute thyroiditis , all are true except
usually virally induced
there is anterior neck pain worsened by coughing, swallowing and movement of the neck
ESR is usually normal
usually responds well to treatment with non steroidal anti inflammatory drugs but steroids are occasionally used for severe cases
the hyperthyroidism per se is usually mild and no treatment is needed for it apart from oral propranolol or certain cases
Factitious hyperthyrosidism , all are true except
it is an uncommon condition due to self administration of T4 the
the radio-iodine uptake scan is suppressed
undetectable serum thyroglobulin
high T3:T4 ratio
the TSH is suppressed
Post-partum thyroiditis
occurs in 5-10% of women in the first 6 months following delivery
thyroid biopsy shows lymphocytic thyroiditis
it tends to recur after subsequent pregnancies
there is an association between post partum depression and post partum thyoriditis
there is a negligible radio-iodine thyroid scan
Hyperthyroid crisis , all are true except
the commonest precipitation factor is infection in a previously undiagnosed or improperly treated hyperthyroidism patient
although being a life threatening increase in the activity of the thyoird gland, fortunately in clinical practice it is rare
rehydration and broad spectrum antibiotics are important in the management
if the patient can not swallow carbimazole then it should be given intravenously
after 10-14 days of treatments with various antithyroid measures, sodium iopodate and propraanolol can be stopped and the patient will continue ni carbimazole
The causes of goitrous hypothyroidism, all a re true except
Hashimoto thyroiditis
Dyshormonogenesis
drug induced
ioidine deficiency
post-ablative
Rare , but well recognized features of hypothyroidism , all are true except :
frank psychosis
myotonia
ascites
ileus
iron deficiency anemia
Biochemical findings that are useful in the assessment of hypothyroidism , all are true except
high serum LDH and CPK
high cholesterol and triglycerides
macrocytic anemia
high serum T3 level
rasied TSH
During treatment of a patient with hypothyroidism all are true except
oral T4 is the cornerstone of treatment
the correct dose of thyroxin is that which restores the serum TSH to normal
the patient usually feels better after 2-3 weeks
restoration of skin and hair texture is usually seen after 3 weeks
elderly patients should be started on a low dose thyroxin with gradual escalation
Myxoedema coma, all are true except
unfortunately the mortality rate is 50% but fortunately the condition is rare.
convulsions are not uncommon and opening CSF pressure may be raised
it is a medical emergency and treatment must be started before the biochemical confirmation
unless there is an evidence of primary hypothyroidism like thyroid scar , it should be considered to be secondary to pituitary or hypothalamic dysfunction .
thyroxin should be given intravenously
During follow up of a patient treated by oral thyroxin for hypothyroidism, all are true except :
it is important to ensure compliance and the drug should be taken infinitely.
once the dose of thyroxin is stabilized based on serum TSH, the TSH and T4 should be measure every 1-2 years
during a visit the combination of raised serum T4 and high TSH indicates a strict compliance
some patients may take thyroxin erratically when they know that the half life is long
excessive sweating, tachycardia and anxiety may indicate over treatment
Medications and thyroid hormones
amiodarone may cause hypo or hyperthyroidism
lithium may cause hypothyroidism
potassium iodide may cause hypothyrodism
phenytoin may decrease the needed dose of thyroxin
oral contraceptive pills may increase the total but not the free thyroxin
Causes of obesity, all a re true except:
Cushing disease
Kallaman syndrome
Prader Willi syndrome
hypothalamic tumors
gastric tumors
Thyroid carcinomas, all are true except:
each type usually has a certain age group to affect
pappilary carcinoma is the commonest type
some tumors are TSH dependent
follicular carcinoma can be diagnosed by FNA cytology
very rarely thyrotoxicosis is seen
Thyroid malignancy, all are true except
pappilary carcinomas usually seen between 20-40 years of age
medullary thyroid carcinoma in a 20 year old man may indicate MEN type II
anaplastic carcinomas usually seen in elderly people
thyroid lymphomas may arise from a preexistent Hashimoto's thyroiditis
secondary tumors are very commonly seen
Medullary thyroid carcinoma, all are true
The prognosis is generally poor when compared with differentiated carcinomas
When seen in a young person, it may be part of MEN type 1
as a treatment option, total thyroidectomy is preferred
high level of calcitonin rarely if ever causes hypocalcemia
the tumor secreting cells do not respond to radio-iodine treatment
Primary Hyperparathyroidism, all are true except
the commonest cause is a single parathyroid adenoma
the commonest cause of out patient hypercalcemia
together with malignancy, they both account for up to 90% of cases of hypercalcemia
lithium induced hyperparathyroidism may present exactly like primary hyperparathyroidism
the parathyroids are usually palpable in the neck
Causes of hypercalcemia with raised level of parathyroid hormone, all are true except
primary hyperparathyroidism
tertiary hyperparathyroidism
lithum-induced hyperparathyroidism
familial hypocalciuric hypercalcemia
malignancy
Treatment of malignancy associated hypercalcemia , all are true except
iv fluids are very important
un very high calicium levels, iv pamidronate is given initially with excellent results
forced diuresis may be used
like primary hyperparathyroidism, glucocorticoides are in effective
there is a place for hemodialysis
Long term Hypocalcemia , all are true except
may be seen in peudopseudohypoparathyroidism
may be a cause of cateract
basal ganglia calcification is seen
pappilodema has been documented
mucocutaneous candidiasis is an association
Causes of hypocalcemia and hyperphosphatemia , all are true except
chronic renal failure
hypoparathyroidism
pseudohypoparathyroidism
hypomagnesemia
pseudopseudohypoparathryoidism
Hypocalcemia, all are true except
carpo-pedal spasm is more common in children than adults
in adults, stridor is uncommon
siezures are usually resistant to antiepileptic therapy
the cornerstone in the treatment of pseudohypoparathyroidism is calcium supplement
regualr follow up is need with measurement of serum calcium
Cushing syndrome in general, all are true except:
obesity is the commonest sign
hypertension is absent in 25% of cases
prominent hyper-pigmentation is in favor of an ectopic ACTH secreting source
depression is the commonest psychiatric manifestation
mucsle biopsy will show type I fiber atrophy
In the diagnosis of Cushing syndrome, all are true except:
In the diagnosis of Cushing syndrome, all are true except:
24 hours urinary free cortisol or overnight low dose dexamethasone suppression test are the preferred initial screening tests
unfortunately dexamethason cross reacts with cortisol immunoassay
chronic alcoholism sometimes exactly resembles Cushing's syndrome clinically and biochemically
supprssed ACTH levels indicate an adrenal tumor
Treatment of Cushing syndrome, all are true
in pituitary dependent disease, trans-sphenoidal surgery is the preferred option
if treated by bilateral adrenalectomy, the pituitary should be irradiated to prevent the development of Nelson's syndrome
medical treatment is usually given in the way to prepare the patient for surgery
adrenal carcinoma should be removed surgically and the tumor bed is irradiated and then the patient is given the drug o'p'DDD
without treatment, the 5 year survival rate is 75%
Causes of apparent hyperaldosteronism , all are true except
treamtent with carbenoxolone
11 deoxycorticosterone secreting tumors
Liddle's syndrome
ectopic ACTH syndrome
glucocorticoides suppressible hyperaldosterosnism
In primary aldosteronism , all are true except
hypertension is almost always present and is the commonest presenting feature
serum potassium is normal up to 70% of cases at the time of diagnosis
of all causes, only Conn's adenoma can be treated by surgery
spironolactone is very effective in normalizing the blood pressure and biochemical abnormalities in the majority of cases
leg edema is very common
Pheochromocytoma, all are true except
may be part of specific syndromes
predominantly elevated noradrenalin suggests either a large adrenal tumor or an extra adrenal tumor
weight loss indicates associated diabetes mellitus
postural hypotension may be seen
the rise in blood pressure may occur during urination
Addison's disease, all are true except
the commonest cause is autoimmune adrenalitis
vitilligo is seen in 20% of cases
hyperglycemia indicates associated type I diabetes
postural hypotension is indicates glucocorticoids rather than mineralocorticoids deficiency
it is a common condition with an incidence of 80 new case/ million of population
Congenital adrenal hyperplasia, all are true except :
the commonest cause is 21 alpha hydroxylase deficiency
all cases are autosomal recessive
causes ambiguous genitalia in females and precocious pseudopuberty in males
11 beta and 17 alpha hydroxylases are associated with hypotension
the condition can be prevented by appropriate prenatal diagnosis and giving dexamethason to the pregnant mother
Drug induced gymecomastia may be due to all of the followings except
digoxin
cimetidin
stilboestrol
spironolactone
ameloride
In polycystic ovarian syndrome , all are true except :
insuline resistance is though to be the central key in the pathogenesis
mild elevation in serum prolactin
mild elevation of serum androgens
elevated blood estron level
FSH:LH ratio more than 2.5:1
In the assessment of hirsutism in a female, all are important clues to the underlying cause except
as idiopathic hirsutism is the commonest cause so being an Asian or Mediterranean is important clue to it
high levels of androgens that don’t suppress with steroids or estrogens is a very important clue to ovarian or adrenal tumors
being a highly trained athletic female may suggest an exogenic androgen intake
mooning of the face with obesity and striae may be a clue to Cushing's syndrome
family history of hirsutism is not that important
MEN type I and type II , all are true except :
due to mutation in MENIN gene on chromosome 11 in type
hypercalcemia is the commonest presenting feature in type II
family history of one relevant endocrine tumor may be present
pheochromocytomas in type II are bilateral in 70% of cases
carcinoid syndrome is uncommon in type I
Carcinoid tumors and syndromes , all are true except :
the commonest site is the ileum for carcinoid tumors
may present as appendicitis
the long term prognosis is excellent in the majority
carcinoid syndrome may present as right sided heart failure
cramping abdominal pain and diarrhea with flushing and wheeze is the commonest presenting feature of carcinoid tumors
In pancreatic endocrine tumors , all are true except :
somatostatinomas may presents with gall stones and diabetes
glucagonomas may present with anemia and weight loss
gastrinomas may present with steatorrhea
VIPOmas may present with watery diarrhea and hyperkalemia
