endocrine disorders Flashcards
hormone producing cells of thyroid gland
follicular cells and parafollicular cells
follicular cells
produce, store and release thyroxine (t4) and triiodothyronine (t3) (active forms); major regulators of the basal metabolic rate
parafollicular cells “c cells”
secrete calcitonin, hormone that has minor role in maintaining calcium homeostasis
what is the rate limiting step in thyroid hormone synthesis
follicular cells capturing iodide from circulation
s/sx of thyroid nodule
pain, pressure, or hoarseness may suggest local invasiveness and should be assessed
evaluation of thyroid nodule/mass
palpate while pt swallows; indirect/direct laryngoscopy (hoarseness,pain, malig); TSH test and thyroid function test; serum Ca levels (hx radiation or MEN); FNA*; US
what does low level tsh suggest
thyrotoxicosis
what does high level of tsh suggest
underactivity (assoc w Hashimoto’s thyroiditis)
what does thyroid function test include
TSH and T4, sometimes T3
if pt has Grave’s ds what thyroid tests should be ordered
t4, t3, tsh, tbg, tsab only if toxic symptoms
pt related to someone w men2 should have what test
urinary catecholamines and catecholamine metabolites screened for functional pheochromocytoma
what is the only thyroid cancer that reliably expresses a tumor marker that is measurable in serum (calcitonin)
medullary carcinoma
pheochromocytoma
neoplasm of the adrenal medulla; arises from chromaffin tissue of neural crest origin; secretes excess epinephrine, norepinephrine, dopamine, or other vasoactive amine; causes a constellation of signs and symptoms as a result of catecholaminemia; associated with the familial endocrine syndromes multiple endocrine neoplasia types 2A (MEN-2A) and 2B (MEN-2B)
single most important study in evaluating a thyroid mass
fine needle aspiration cytology
grading system of fna of thyroid nodule
follicular cells (5% risk), follicular cells w atypic (25%), suspicious for papillary carcinoma (75-95), papillary carcinoma (100%)
tx solid thyroid nodule low risk for malignancy on fna
observation 3-6m while on oral thyroid hormone to suppress TSH stimulation of tumor growth (suppress to mid-low range w careful monitoring); remains same size then reaspirated; larger=excised
suppression TSH to very low levels inc risk for
osteoporosis and new onset atrial fibrillation
tx thyroid nodule w cancer
thyroid lobectomy and isthmectomy to remove ipsilateral lobe of thyroid gland along with isthmus; or complete thyroidectomy removes the full tumor
why should frozen sample of thyroid not be used to analyze for cancer
causes great deal of distortion and dx is often subtle
performing lobectomy or total thyroidectomy, great care is taken to preserve what
parathyroid glands and their blood supply; recurrent laryngeal nerve and external branch of superior laryngeal nerve (voice quality)
injury to recurrent laryngeal nerve during thyroid lobectomy causes
paralysis of ipsilateral vocal cord which becomes immobile in paramedic position; leaves pt w weak, breathy voice; (if thyroidectomy b/l injury causes loss of speech and airway control and requires tracheostomy)
mc cause of hyperthyroidism
Grave’s ds or diffuse toxic goiter
Grave’s ds
autoimmune thyrotoxicosis
goiter
thyroid enlargement
toxic multinodular goiter
thyroid enlargement from multiple nodules that may cause compression symptoms
diffusely enlarged, soft gland w homogeneous increased radionuclide uptake and no nodules
Grave’s ds
solitary nodule w inc uptake against background of suppressed uptake in remaining thyroid
toxic adenoma
diffusely multinodular gland, heterogeneous radionuclide uptake, and multiple nodules of varying sizes on us
toxic multinodular goiter
hyperthyroidism, exophthalmos tachycardia, tremor; heat intolerance, wl
graves; result from excessive production of thyroid hormone
s/sx of hyperthyroidism
nervousness, restlessness, emotional lability, fast speech, fine tremor, tachycardia, palpitations, arrhythmias, dyspnea, lid lag, proptosis, exophthalmos, ophthalmopathy, inc sweating, fatigue, weakness, hair loss, leg swelling, pretrial myxedema
what can determine is hyperthyroidism is pituitary dependent or independent
serum TSH levels: tsh dec w thyroid and inc w pituitary;
hyperthyroidism assoc w Graves ds is caused by
circulating immunoglobulin G (IgG), immunoglobulin (thyrotropin receptor antibody [TRAb]) that is directed against the TSH receptors on the follicular cells of the thyroid. This antibody stimulates the thyroid to generate and secrete thyroid hormone, but the sensitivity to the negative feedback system that controls normal thyroid function is lost. Thus, TRAbs causes excessive production of T3 and T4 and progressive hyperthyroidism. The pathogenesis of the exophthalmos and the pretibial myxedema of Graves’ disease is the result of expression of TSH receptors by the retro-orbital tissues
tx Graves
medical blockade of hormone and se; radio iodine ablation of active thyroid tissue; surgical resection;
medical blockade of hormone and se in graves
iodide and propranolon role in short term or preop prep but not definitive; thionamides (propylthiouracil “put”, methimazole “tapazole”) 6-12m but has sig se
se of thionamides
recurrent/persisten hyperthyroidism; intolerance of meds including cholestasis, arthralgia, headache, neuritis, dependent edema; reversible agranulocytosis
radioablation for graves
isotope is 131I at dose of 80muCi/g; 2nd/3rd dose if hyperthyroidism after 6m; safe and effective; completely destroys cells rather than altering DNA
solitary tumor of the thyroid gland that produces excessive amounts of thyroid hormone and causes clinically overt hyperthroidism
toxic adenoma
how does thyroid adenoma present
similar to graves with exception of ophthalmopathy or pretrial myxedema because it is not an autoimmune ds
eval differing graves and toxic adenoma
Serum thyroid hormone levels show high T3 and T4 and suppressed TSH, consistent with an autonomous thyroid source of the excessive thyroid hormone production. The differentiation between hyperthyroidism caused by Graves’ disease and that caused by toxic adenoma depends on the characteristics of the thyroid on physical examination and scan. In patients with Graves’ disease, the thyroid is diffusely enlarged. In patients with toxic adenoma, it is normal or small, with a palpable nodule that is “hot,” or functional, on thyroid scan.
tx toxic adenoma
After preoperative preparation, usually with propranolol or one of the thionamides, the lobe with the “hot” nodule is excised by thyroid lobectomy and isthmectomy. Surgery is also considered optimal therapy for a toxic multinodular goiter (Plummer’s disease). Total thyroidectomy is indicated, especially if the goiter is large and associated with symptoms such as compression
Plummer’s ds
toxic multinodular goiter
auto dom condition caused by mutation of RET
familial medullary thyroid carcinoma
cancers from follicular cells
(papillary and follicular varieties) well differentiated thyroid cancers; hurthle or oxyphil cell tumors; anaplastic tumors
parafollicular cell cancers
medullary carcinoma (lymphoid cells to lymphoma)
mc thyroid malignancy in US
papillary carcinoma
tumors w a mix of papillary and follicular features are classified how
as papillary cancers because they have similar biologic behavior
what are papillary carcinomas characterized by
concentric layers of calcium (psammoma bodies) found in the stalk formations
papillary cancers grow slow so have excellent prognosis but when does it have a poor prognosis
males, >50yo, primary tumor >4cm, less well differentiated cells, locally invasive or distant metastatic ds
tx papillary carcinoma
lobectomy or total thyroidectomy based on AMES/AGES; lymph node removal if involved; thyroid hormone replacement
distant metastases of papillary carcinoma
lungs and bone; radio iodine
monotonous, relatively uniform appearance of micro follicles; presence of capsular and vascular invasion; slow growing
follicular carcinoma
poor prognostic indicators for follicular carcinoma
> 45yo, local invasion to contiguous neck structures and distant metastases
tx follicular carcinoma
lobectomy or total thyroidectomy based on AMES/AGES; lymph node removal if involved; thyroid hormone replacement
genetically transmitted, auto dom inheritance assoc w familial medullary carcinoma or men type 2a or 2b
medullary carcinoma
location of tumor in pt w fam med cancer or men
both thyroid lobes
location of medullary thyroid carcinoma (MTC)
one lobe; worse prognosis than pap/foll carcinoma
dx medullary cancer
plasma screening that shows elev calcitonin levels or by screening w a calcium and pentagastrin infusion test that shows elev calcitonin
MTC tx
total thyroidectomy and central (level VI) lymph node dissection (removal of cervical lymph nodes medial to both recurrent laryngeal nerves and carotid arteries)
extremely aggressive neoplasm arises from follicular cells
anaplastic carcinoma; survival
how to distinguish lymphoma from hashimoto’s thyroiditis
core needle or open bx
hashimoto’s thyroiditis
autoimmune thyroiditis
yellow brown, ovoid, soft and mobile; attached fatty tissue
parathyroid glands- endocrine glands in neck that secrete parathyroid hormone
parathyroid glands are usually 5mm, what happens as they become larger
darker brown, firm and less fatty
what are the parathyroid glands a sole source of
parathyroid hormone (84 amino acid peptide)
PTH and calcium
hypocalcemia stimulates PTH while hypercalcemia inhibits PTH
roles of PTH
PTH directly increases calcium resorption in the proximal convoluted renal tubule. PTH increases phosphate clearance, but PTH secretion is not influenced by serum phosphate levels. PTH directly mobilizes calcium from bone and stimulates osteoclast activation and bone reabsorption. PTH indirectly increases gastrointestinal calcium absorption by stimulating vitamin D production.
primary hyperparathyroidism
inverse relationship between PTH and serum calcium is disturbed. Although calcium may remain within normal limits, PTH is elevated relative to the serum calcium level. Serum phosphate is often low and renal function is normal
causes of primary hyperparathyroidism
parathyroid adenoma*, parathyroid hyperplasia, parathyroid carcinoma
who does secondary hyperparathyroidism most often occur in
renal failure pts
secondary hyperparathyroidism
progressive nephron loss leads to phosphate retention, decreased calcium absorption, inhibition of 1 α-hydroxylase, and decreased activation of vitamin D. These factors lead to decreased serum calcium and increased secretion of PTH
tertiary hyperparathyroidism
one or more of the hyperplastic glands of a patient with secondary hyperparathyroidism becomes an autonomous producer of PTH
s/sx primary hyperparathyroidism
stones, bones, groans, moans, and psych overtones,” most often urolithiasis (“stones”) or bone diseases including bone resorption with cyst (osteitis cystica) and brown tumor formation (“bones”). Less commonly seen were abdominal pain from peptic ulcers or pancreatitis (“moans”), diffuse joint and muscle pains, fatigue and lethargy (“groans”), and neuropsychiatric abnormalities including depression or worsening psychosis (“psych overtones”).
mc cause of outpatient hypercalcemia
primary hyperparathyroidism
tx hypercalcemia
acute/severe managed by large volume saline infusion; loop diuretics (furosemide); dec bone turnover (bisphosphonates, calcitonin); tx underlying cause
tx primary or tertiary hyperparathyroidism
bisphosphonates (alendronate “fosamax”) or selective estrogen receptor modulators (raloxifene “evista”) to slow bone loss but reserved for pts who can’t be operated on; surgery*
tx secondary hyperparathyroidism
cinacalcet (sensipar)
what does observation for hyperparathyroidism require
biannual serum calcium levels, annual serum creatinine measurement, annual bone mineral density determination
most effective long term tx for pt w end stage renal ds and hyperparathyroidism
renal transplantation
classic open exploration for sporadic primary hyperparathyroidsim
visualization of all cervical glands, characterization of the disease by the surgeon based upon operative observations (uniglandular [adenoma] or multiglandular [hyperplasia]), and resection of sufficient parathyroid tissue to restore long-term eucalcemia while not creating hypoparathyroidism. Exploration is typically performed under general anesthesia. Single-gland resection is performed for adenoma; hyperplasia is most often treated by subtotal (three and one-half gland) resection. Familial syndromes (see MEN) introduce other considerations and alternatives such as total parathyroidectomy with forearm autotransplantation and cryopreservation of excised tissue are often performed.
two directed operative strategies aka minimally invasive or targeted
often applicable to sporadic primary hyperparathyroidism: intraoperative PTH (ioPTH) assay monitoring and radioguidance. Both approaches require that an abnormal parathyroid gland be identified preoperatively to guide the surgeon to the appropriate side of the neck. Such preoperative localization is usually done by sestamibi radionuclide scanning. A nonlocalizing scan precludes radioguided operation. Other imaging modalities (e.g., cervical ultrasonography) may lateralize an abnormal parathyroid gland and still allow an ioPTH-based approach. Both of the directed operations can be performed under cervical block anesthesia combined with conscious sedation or under general anesthesia.
radio guided strategy for hyperpara
injected with sestamibi about 2 hours prior to the start of operation. The incision is placed over the point of maximal radioactivity as detected by a handheld gamma probe. Dissection follows the radioactivity signal to expose abnormal parathyroid tissue, which is excised. Radioactivity should equalize throughout the neck after adenoma removal, and the adenoma should have a radioactivity count at least 20% above the neck background count. Failure to meet these radioactivity criteria mandates continued neck exploration.
tx parathyroid cancer
resection of primary tumor and ipsilateral thyroid lobe
most serious complication of parathyroidectomy
recurrent laryngeal nerve injury
hungry bone syndrome
phosphorus is taken up by the bone w calcium and serum phosphorus will remain low; require supplemental calcium postop until syndrome resolves
what is the only endocrine organ whose activity is controlled entirely by nervous impulses
medulla (neural crest cells)
zona glomerulosa hormone
aldosterone- electrolyte metabolism
hyper secretion of aldosterone from zone glomerulosa
Conn’s syndrome sx of hypokalemia, htn, muscle weakness
zona fasciculate hormones
cortisone and hydrocortisone- protein and carbohydrate metabolism
hyper secretion of cortisone
cushings syndrome/ds- buffalo hump, violaceous striae, moon faces, truncal obesity, htn
hormones of zone reticularis
progesterone, androgen, estorgen- sexual differentiation
hyper secretion of zone reticularis hormones
adrenogenital syndrome- virilism/feminization
medulla hormone
epinephrine, norepinephrine
hypersecretion epinephrine
pheochromocytoma- episodic htn; headache,sweating,palpitations
difference between cushing’s syndrome and cushing’s disease
syndrome is s/sx of hypercortisohsm whereas ds is hypercortisohsm due to an ACTH producing pituitary adenoma
presentation of CS
3/4th decades, female, truncal obesity, htn, diabetes, weakness, purple striae, hirsutism, moon facies, and buffalo hump; depression, mental changes, osteoporosis, kidney stones, polyuria, fungal skin infx, poor wound healing, menstraul disturbances, acne
what happens during CS
diurnal variation in glucocorticoid secretion (high levels in the morning, declining during the day, with lowest levels in the evening) and the ability of the adrenal gland to increase cortisol secretion in response to ACTH stimulation are either lost or blunted
what happens when Cs is due to ectopic ACTH and pituitary tumors
melanotropins are also secreted, leading to inc skin pigmentation
screening tests for CS
urinary free cortisol (UFC; at least 2 measurements), late-night salivary cortisol (2 measurements) and 1-mg overnight dexamethasone suppression test (DST)
24hr urinary excretion test results
free cortisol >300 μg is diagnostic for CS, 45 to 300 μg is indeterminate, and
what test segregates pts into ACTH dependent or ACTH independent subtypes
plasma ACTH measurement; pt w suppressed ACTH level
what imaging tests are used to dx primary adrenal tumor
CT scan or MRI of abdomen to localize mass;
causes of unilateral masses on CT or MRI of adrenals
adenomas or ACCs and they are usually radiographically distinct because ACCs are rarely
causes of bilateral masses on CT/MRI of adrenals
primary pigmented nodular adrenocortical disease (PPNAD), ACTH-independent macronodular adrenal hyperplasia (AIMAH), or bilateral cortisol-secreting adenomas..
what should a pt have done if ACTH level is normal or inc
pituitary MRI
what should happen if pituitary MRI shows hypo dense, non enhancing >5mm mass
tumor and consistent w clinical findings then tx by transsphenoidal surgery
what if the pituitary MRI is normal or equivocal
inferior petrosal sius sampling (IPSS) should be performed; if that does not reveal tumor then further workup for ectopic sources of ACTH required (ct, mri, neck us, scintigraphy, tumor markers)
medical tx for cushings disease
temporary control by using agents that inhibit steroid biosynthesis such as metyrapone, ketoconazole, or aminoglutethimide;
DDT derivative, mitotane, toxic to adrenal cortex but has serious se;
radiation but can take 1 year and recurrence common
surgical tx cushing’s ds
if caused by pituitary adenoma then transsphenoidal microadenomectomy;
TSS fails then bilateral laparoscopic adrenalectomy, radiotherapy, and/or total hypophysectomy
what syndrome can be seen after bilateral adrenalectomy
nelsons- hyperpigmentation,headaches, exophthalmos, visual field loss from progression of ACTH secreting pituitary adenoma
cause of primary adrenal hypercortisolism in 80-90% of pts
solitary adenomasAs a result of the hypersecretion of cortisol and inhibition of ACTH, the remaining adrenal tissue on the ipsilateral side and the contralateral adrenal tissue atrophy and function poorly until the adenoma is removed
tx for adrenal adenoma
preop steroids; lap unilateral adrenalectomy postop maintenance doses of prednisone or hydrocortisone until normal adrenal function (12-18months)
tx of adrenal cortical carcinoma
open unilateral adrenalectomy
tx primary adrenal hyperplasia (PPNAD or AIMAH)
lap bilateral adrenalectomy
tx pt w bilateral cortisol secreting adenomas
bilateral cortical sparing lap adrenalectomy
primary aldosteronism (PA) “conn’s syndrome”
women 4-6decades; produce excess aldosterone that is not responsive to rennin-angiotensin axis and not suppressed by salt loading
causes of primary aldosteronism
adrenal adenoma, diffuse hyperplasia, or nodular (adenomatous) hyperplasia of adrenal cortex
presentation of primary aldosteronism
inc total body sodium, dec potassium level (hypokalemia), inc extracellular vol resulting in metabolic alkalosis and HTN; hypomagnesemia, tetany, periodic paralysis
biochemical findings of primary aldosteronism
persistently elevated plasma and urinary aldosterone levels and dec plasma renin activity unresponsive to stimulation
aldosterone is normally secreted in response to
reduced effective blood volume and renal blood flow, sodium depletion or restriction, and potassium loading. It stimulates absorption of sodium at the distal convoluted and cortical collecting tubules. Sodium is reabsorbed at the expense of hydrogen and potassium ions.
definition of primary hyperaldosteronism
inappropriate hyper secretion of aldosterone in the absence of activation of the renin-angiotensin system
dx of primary hyperaldosteronism is suspected in pts w
moderate or severe hypertension or drug-resistant hypertension, hypertension and hypokalemia, hypertension and an adrenal lesion or hypertension in a patient with a family history of PA, early-onset hypertension, or the sequelae of hypertension
secondary hyperaldosteronism is a normal homeostatic response to
volume or salt depletion and assoc w elevated plasma renin activity and elevated or high normal aldosterone levels; cirrhosis, nephrotic syndrome and CHF
dx for primary hyperaldosteronism
aldosterone-to-renin ratio (ARR) is initial screening test (hypokalemia should be corrected beforehand and no restriction of sodium intake); if positive (>20) then confirmation w oral sodium loading, saline infusion, fludrocortisone suppression or captopril challenge tests done; once confirmed CT scan of abdomen
what should be stopped 4 weeks prior to ARR testing for primary hyperaldosteronism
spironolactone, potassium wasting diuretics, chewing tobacco
tx primary hyperaldosteronism
unilateral aldosteronomas have HTN and hypokalemia normalized prior to surgical intervention (w mineralocorticoid receptor antagonist ex spironolactone); lap unilateral adrenalectomy; if ds not localized to one adrenal gland then managed w spironolactone and symptomatic tx
large (>6cm), encapsulated, friable, and have extensive central necrosis and hemorrhage
adrenal cortical carcinoma (ACC)
presentation of adrenal cortical carcinoma (ACC)
cushing syndrome (50%), virilizing, feminizing, and purely aldosterone secreting carcinomas (15%), hormonally active only by biochemical studies (10%); abdominal mass; weight loss, weakness, fever and bone pain (metastases)
women with virilizing ACC s/sx
hirsutism, temporal balding, inc muscle mass, amenorrhea
men with virilizing ACC s/sx
gynecomastia, testicular atrophy, impotence, or dec libido; (boys w precocious puberty)
dx ACC
ct scan; carcinoma then larger size (8-15cm), irregular borders, heterogeneity, evidence of central necrosis, stippled calcifications, regional adenopathy, invasion of adjacent structures, presence of metastases;
MRI in delineating vascular extension
tx ACC
surgical excision w total gross tumor removal; if local invasion or visceral metastases, ipsilateral nephrectomy and resection of contiguous structures or hepatic metastases;
postop corticosteroid replacement
follow up low grade ACC
imaging every 3-6m, if bio markers were elevated then should also be followed
follow up high grade ACC
external beam radiation to the tumor bed and adjuvant mitotane chemo plus imaging every 3-6m, +/- biomarkers;
(metastic/unresectable-just chemo)
dx approach to the adrenal incidentaloma should consist of
clinical, lab, and imaging eval to rule out hypercortisolism, aldosteronism (if hypertensive), pheochromocytoma or malignant adrenal lesion
initial step in est whether an incidentaloma is hormonally active
1mg overnight DST to eval for excess cortisol; if high clinical suspicion due to htn, obesity, diabetes or osteoporosis then combine salivary cortisol, dexamethasone suppression and urine free cortisol tests
after initial step to see if incidentaloma is active what is next step
radiographic findings concerning for malignancy:
If the lesion is 4 cm and has features that are indeterminate or consistent with malignancy, a hormonal workup should be completed and the tumor surgically removed as is appropriate based on the suspected etiology.
final step in eval incidentaloma
eval if at risk for metazoic ds, hypercortisolism, aldosteronism, or pheo;
for pheo plasma fractionated metanephrines and normetanephrines or 24hr total urinary metanephrines and fractionated catecholamines checked
tx of incidentaloma if no evidence of adrenal tumor
just f/u radiographic test 3-6m after initial dx and then annually for 1-2yrs w eval for hormonal disturbances at time of dx and then each year for 5 yrs
defined by WHO as tumors arising from catecholamine producing chromatin cells in adrenal medulla
pheochromocytoma
what do most pheochromocytoma’s produce
norepinephrine and epinephrine; few produce epi only (MEN2)
locations of pheos
abd cavity (98%), bladder and organ of zuckerkandl
s/sx pheo
palpitations, headache, sweating ; impending doom, significant anxiety, wl, constipation; pallor, flushing, sweating; attacks last 15m or less
dx pheo
plasma-free metanephrine and normetanephrine or urine metanephrine, chest and abdominal CT or MRI, and genetic counseling. If patients are having bone symptoms a bone scan is indicated, and if there is a suspicion of multiple tumors or if CT is negative, MIBG (metaiodobenzylguanidine) scan/Octreoscan is indicated.
tx pheo
alpha blockage (phenoxybenzamine) +/- alpha methyltyrosine; after alpha is blocked, beta blockade is used 10d prior to surgery or if pt is tachycardic; resectable lap adrenalectomy;unresecTable pheochromocytoma should have a cytoreductive resection if possible, alphablockade and possible radiation therapy without alpha-methyltyrosine and/or beta-blockade
f/u postop pheo
pe including bp and catecholamines checked every 3m and then every 6m for 3 years and then annually after 4yrs w imaging as indicated
chemo for pheo
dacarbazine, cyclophosphamide, vincristine or 131I MIBG;
complications of adrenalectomy
htn, hemorrhage, adrenal insufficiency, Addisonian crisis,
causative gene in men1
tumor suppressor gene located on long arm of chromosome 11 that encodes the protein menin
testing and screening men1
Screening of MEN-1 carriers is performed annually. When DNA tests are not feasible or informative, individuals at 50% risk (i.e., first-degree relatives of known MEN-1 patients) should be screened every 3 years. Screening includes tests for the common lesions of MEN-1 (calcium, prolactin, fasting glucose and insulin, gastrin). Other tests are added based upon individual patient evaluation and family history. Patients from MEN-1 kindreds with known mutations who have negative genetic testing do not require further genetic or biochemical screening.
mc endocrine disorder in men1
primary hyperparathyroidism
s/sx MEN1
asymptomatic hypercalcemia, constitutional and neuropsychiatric complaints (weakness, fatigue, irritability, depression), urinary tract findings (urolithiasis, hypercalciuria), abdominal pain (peptic ulcer disease, pancreatitis), and bone disease (decreased bone density, bone pain, fractures)
tx MEN1 hyperparathyroidism
b/l neck exploration; total (4) or subtotal (3.5) parathyroidectomy along with removal of cervical thymus; parathyroid tissue cryopreserved for forearm reimplantation
mc islet cell neoplasm in MEN1 secretes
pancreatic polypeptide(nonfunctional) while gastrinoma is the most frequent functional tumor
s/sx islet cell MEN1
ZE syndrome (PUD, diarrhea, esophagitis), insulinoma (drowsiness, seizures, coma), gain weight, glucagonoma (hyperglycemia, cachexia, anemia, rash)
tx MEN1 islet cells
surgery if insulinoma; gastrinoma PPI
s/sx pituitary tumors in MEN1
secrete prolactin, producing irregular menses, galactorrhea, infertility, and impotence
tx prolactinomas w pituitary tumors in MEN1
bromocriptine
RET positive pts should undergo total thyroidectomy before what age
6yo to prevent MTC
s/sx MEN2b
marfanoid habitus, prognathism, puffy lips, bumpy tongue, hyper flexible joints, corneal nerve hypertrophy; all confirmed by RET testing
MTC is most aggressive in which MEN
MEN 2B
A 20-year-old woman is seen in clinic because of a thyroid nodule. She Is asymptomatic and her past medical history is unremarkable. She takes no medications. There Is a 1 -cm firm, solitary, nodule in the lateral aspect of the left lobe of the thyroid. A radionuclide scan showed no uptake of tracer In the nodule. Ultrasonography shows a solid, homogenous 1 -cm mass. Fine-needle aspiration cytology shows a follicular neoplasm. What Is the next best step in management?
This patient should undergo a thyroid lobectomy. Even though an FNA showing follicular cells is only 5% likely to be a malignancy, most endocrine surgeons would recommend excision because of that concern. Radioactive Iodine is inappropriate because it would destroy normal thyroid and leave the nodule. Suppression with levothyroxlne to suppress thyroid-stimulating hormone (TSH) to below normal limits Is associated with accelerated osteoporosis and cardiac irregularities. Suppression to within normal range could be a temporizing maneuver. Incisional biopsy and enucleation are Inappropriate because neither will allow examination of the interface between the nodule and normal thyroid and potentially not allow the diagnosis of a follicular variant of papillary thyroid carcinoma. Total thyroidectomy Is unnecessarily aggressive
A 50-year-old woman Is seen In clinic because of weight loss, restlessness, and palpitations. She also has noted leg swelling and excessive hair loss. Her past medical history is unremarkable. She takes no medications. She is afebrile. On exam, she is tachycardlc and has a fine tremor. She has mild exophthalmos. Her thyroid Is smooth and uniformly enlarged. TSH levels are low and T3 and T4 levels are elevated. What is the next best step In management?
The patient has Graves’ disease. Initial treatment should be with antithyroid medication to suppress thyroxine production. Radioactive Iodine as the first line of treatment is inappropriate because as many as 75% of patients have been reported to have sustained remission after 3 to 6 months of treatment with antithyroid drugs. Early operation Is too aggressive when nonoperative methods of treatment are available. Propranolol may be used as an adjunct to antithyroid medications but used alone does not help suppress the thyrotropin receptor antibodies (TRAbs) that are responsible for Graves’ disease. The highest rates of remission are associated with elimination of these antibodies. Thyroxine suppression will be ineffective since the patient already has high levels of T4.
A 25-year-old otherwise healthy woman is found to have a serum calcium of 10.9 mg/dL (normal 8.2 to 10.2 mg/dL) during a well-woman preventive medicine visit. A parathyroid hormone (PTH) level returns 75 pg/mL (normal 13 to 65 pg/mL). She is asymptomatic. She takes no chronic medications. Family history discloses that her mother has hypercalcemia that has never required medication or operation. Physical examination is normal. The patient is most likely to have which of the following laboratory findings?
This asymptomatic patient with mild elevations of calcium and Intact PTH levels and a family history of benign hypercalcemia most likely has FHH, familial hypercalcemlc hypocalclurla. The diagnosis can be confirmed by a 24-hour urine collection for calcium and creatinine, which should show calcium
A 40-year-old healthy woman is found to have a serum calcium level of 11 mg/dL during a preventive medicine visit. She Is otherwise healthy and takes no medications. There is no family history of endocrine disease. Serum phosphorus Is 2.4 mg/dL and PTH level is 90 pg/mL. Sestamibi scan is without focal uptake. Cervical ultrasonography demonstrates a 15-mm ovoid hypoecholc solid soft tissue mass immediately adjacent and lateral to the Inferior pole of the right thyroid lobe. Which one of the following is the most appropriate treatment recommendation for this patient?
This patient has early sporadic primary hyperparathyroidism. While she Is asymptomatic, she meets the NIH consensus criterion for parathyroid operation of age
A 35-year-old woman Is seen in clinic because of weight gain and abnormal hair growth. She has gained 15 kg in 6 months, most notably In her torso. She denies increased appetite and has not changed her daily activity patterns. She has been emotionally labile and her previously regular menses have become Irregular (periods are shorter or missed altogether). On examination, she has truncal obesity and hirsutism. The most likely primary cause of her symptoms is due to hyperfunction of which one of the following?
This patient has symptoms and signs of hypercortlsolism (Cushing’s syndrome). The most common cause of Cushing’s syndrome In adults Is an adrenocorticotropic hormone (ACTH)-secreting tumor of the pituitary basophils (Cushing’s disease). Women in the third and fourth decades of life are the typical patients. Cushing’s disease accounts for 70% of cases of Cushing’s syndrome. Bronchial carcinoid tumors (arising from Kulchitsky cells) are a source of ectopic ACTH production. Ectopic ACTH syndrome causes about 15% of Cushing’s syndrome In adults. The adrenal medulla does not produce glucocorticoids; tumors of the medulla are pheochromocytomas and produce excess catecholamines. A tumor of ovarian epithelial cells could lead to menstrual Irregularities through excess sex steroid production but would not produce hypercortisollsm.
