Flashcards
Endocrine
Cards in this deck (77)
- 1Thyroid development (where is it from? ectopic thyroid tissue? embryonic origin?)Thyroid diverticulum
- arises from floor of primitive pharynx --> descends into neck --> leaves behind thyroglossal duct
- originates from endoderm
Thyroglossal duct
- usually disappears
- foramen cecum: normal remnant of thyroglossal duct
- cyst may present as an anterior midline neck mass
Most common ectopic thyroid tissue site is the tongue
- parafollicular cells (calcitonin) are derived from neural crest - 2Adrenal cortex and medulla (embryonic origin of cortex? of medulla?)
- 3Pituitary gland (anterior secretion? intermediate? posterior?)Anterior pituitary
- Acidophils
1. somatotrophs --> GH (growth hormone)
2. Lactotrophs --> prolactin
- Basophils
3. Gonadotrophs --> LH, FSH
4. Corticotrphs --> ACTH
5. Thyrotrophs --> TSH
*ACTH and MSH - derivatives of POMC*
Intermediate pituitary
- Melanotropin (MSH)
- from oral ectoderm (anterior too)
Posterior Pituitary
- Stores and releases vasopressin and oxytocin (both made in hypothalamus - supraoptic and paraventricular nuclei)
- from neuroectoderm - 4Endocrine pancreas cell typeIslets of langerhans (a, B, and d endocrine cells)
- a-cell: glucagon (peripheral)
- B-cell: insulin (central)
- d-cell: somatostatin (interspersed)
- 5Insulin (regulation? synthesis? source?)Regulation
- Glucose (main regulator) --> enters B-cells --> (+) ATP --> closes K-channels (sulfonylurea target) --> Voltage-gated Ca channels open --> Ca influx --> stimulation of insulin exocytosis + synthesis
Synthesis:
Preproinsulin (from RER) --> cleavage of pre-signal (directs traffic)--> proinsulin (stored in secretory granules) --> cleavage of proinsulin --> exocytosis of insulin and C-peptide
Source:
B-cells
- 6Insulin (function) (insulin dependent tissues? effects of insulin? insulin-dependent transporters?)Insulin-dependent tissues:
A) GLUT-4:
1) adipose tissue
2) striated muscle (exercise increases GLUT-4 expression)
Effects of insulin
1. (+) glucose transport into skeletal muscle and adipose tissue
2. (+) glycogen synthesis and storage
3. (+) triglyceride synthesis
4. (+) Na retention (kidneys)
5. (+) protein synthesis
6. (+) cellular uptake of K and amino acids
7. (-) glucagon release
8. (-) lipolysis in adipose tissue
Insulin-independent transporters:
1. GLUT-1: RBCs, Brain, Cornea, Placenta
2. GLUT-2 (bidirectional): B-cells, liver, kidney, small intestine
3. GLUT-3: brain, placenta
4. GLUT-5 (fructose): spermatocytes, GI tract - 7Glucagon (source? function? regulation?)Source: a-cells of pancreas
Function (catabolic)
1. Glycogenolysis, gluconeogenesis
2. Lipolysis --> ketone production
Regulation:
(+) in Hypoglycemia
(-) w/ insulin, hyperglycemia, somatostatin - 8Hypothalamic-pituitary hormones (and what they control)GnRH, GHRH, Somatostatin (SS), TRH, Dopamine (DA), CRH
- 9Prolactin (source? function? regulation?)Source: anterior pituitary (similar in structure to growth hormone)
Function
1. Stimulate milk production
2. Inhibits ovulation in females (inhibits GnRH synthesis)
3. Inhibits spermatogenesis + libido(inhibits GnRH synthesis)
Regulation
1. Tonically inhibited by dopamine (DA) from hypothalamus
a) dopamine agonists treats prolactinoma
b) dopamine antagonist stimulates prolactin secretion
2. Prolactin inhibits its own secretion (by increasing DA secretion and synthesis)
3. TRH (+) prolactin secretion
4. Renal failure --> doesn't get rid of prolactin --> (+) galactorrhea
5. Nipple stimulation (+)
6. Chest wall injury (+)
- 10Growth Hormone (source? function? regulation? excessive GH? treatment of that?)Somatotropin
Source: anterior pituitary
Function:
1. Stimulates linear growth (via IGF-1)
2. Stimulates muscle growth (via IGF-1)
3. Raises [glucose] (hence it (+) insulin resistance)
Regulation
1. Released in pulses in response to GHRH
2. (+) secretion during exercise
3. (+) during deep sleep
4. (+) during puberty
5. (+) by hypoglycemia
6. (-) by high serum [glucose]
7. (-) by somatostatin
Excessive GH (pituitary adenoma)
1. Acromegaly (adults)
2. Gigantism (children)
Treat w/ somatostatin - 11Appetite regulation (which hormones? their regulation and mechanism of action?)Ghrelin
- produced by stomach
- stimulates hunger and GH release
- (+) by:
1. Sleep deprivation
2. Prader-Willi syndrome
Leptin
- adipose tissue produces leptin
- induces satiety
- (-) by:
1. Sleep deprivation
2. Starvation
- mutation --> congenital obesity
Endocannabinoids
- act at cannabinoid receptors in hypothalamus + nucleus accumbens
- both areas control hunger --> (+) appetite - 12Antidiuretic hormone (ADH --> source? function? regulation?)Source:
Hypothalamus synthesis --> stored in posterior pituitary
Function
1. regulates SERUM OSMOLARITY (V2 receptors --> insertion of aquaporin in renal collecting duct)
2. Regulates blood pressure - (V1 receptors --> constricts vascular smooth muscles)
Regulated by osmoreceptors in hypothalamus
1. Inc. in hypovolemia - 13Adrenal steroid synthesis (know the pathway, compounds, and key enzymes)
- 14Congenital Adrenal Hyperplasia (most common etiology) (pathogenesis? findings - both types? clinical signs? management?)21-hydroxylase deficiency
Pathogenesis
autosomal recessive loss of 21-hydroxylase --> no mineralocorticoid or glucocorticoid synthesis --> too much androgen AND too much ACTH stimulation AND too much renin stimulation --> adrenal hyperplasia
Classic type:
1. Present at newborn period
2. If XX --> ambiguous genitalia (clitoral enlargement)
3. Salt wasting (poor feeding, poor weight gain, hyperkalemia, dehydration)
4. Life-threatening hypotension
5. Peak of clinical adrenal crises at 10/14 days after birth
Clinical signs:
1. Elevated 17-OH-progesterone
2. Elevated DHEA
3. Androstenedione
management:
1. Glucocorticoid replacement (hydrocortisone)
2. Mineralocorticoid replacement (fludrocortisone)
3. Optimize androgen suppression
4. Proper stress management
Non-classic type:
1. Glucocorticoid deficiency rare
2. Mineralocorticoid deficiency NONE
3. Prenatal virilization NONE
4. Postnatal virilization variable
5. Rapid growth --> advanced bone maturation --> short stature as adults - 1517-a-hydroxylase deficiency (if XX? if XY?)(+) mineralocorticoids
(-) cortisol
(-) sex hormones
(+) Blood pressure
(-) K
Labs: decreased androstenedione
XY will present w/ ambiguous genitalia + undescended testes
XX will lack 2* sexual development
Congenital adrenal hyperplasia - 1611-B-hydroxylase deficiency(-) aldosterone slightly
(+) 11-deoxycorticosterone --> (+) BP
(-) cortisol
(+) sex hormones
(+) BP
(-) K
(-) renin activity
XX: virilization
Also congenital adrenal hyperplasia - 17Cortisol (source? regulation? function?)Source:
Adrenal zona fasciculata (but bound to protein)
Regulation
CRH (hypothalamus) --> ACTH (pituitary) --> cortisol production
Excess cortisol --> (-) CRH --> (-) ACTH
Function:
1. (+) BP (upregulaes a1-receptors)
2. (+) insulin resistance
3. (+) gluconeogenesis, lipolysis, proteolysis
4. (-) Fibroblast activity (striae)
5. (-) inflammatory and immune responses
a) blocks phospholipase A2
b) blocks 5-lipoxygenase
c) blocks COX
d) inhibits leukocyte adhesion
e) inhibits Mast cell histamine release
f) reduces IL-2 production
6. (-) bone formation - 18Calcium homeostasis (states of existence? if pH increases?)plasma Ca exist in 3 forms:
1. Ionized (45%)
2. Bound to albumin (40%)
3. Bound to anions (15%)
If pH increases --> albumin more basic --> binds to more Ca --> hypocalcemia - 19Vit D (cholecalciferol) (source? regulation? function? cause of deficiency? deficiency manifestations?)Source:
1. Skin + sun/fish/dairy --> D3
2. Plants/fungi/yeast --> D2
3. Converted to 25-OH in liver
4. Converted to 1,25-OH in kidney
Regulation
1. (+) PTH --> (+) Vit D
2. (-) Ca --> (+) Vit D
3. (-) PO4 --> (+) Vit D
4. Vit D --> (-) Vit D production
Function
1. Inc. absorption of Ca and PO4 in small intestine
2. Inc. osteoclast number --> maintains healthy bone by maintaining [Ca] and [PO4]
Cause of deficiency
1. Malabsorption
2. Dec. sunlight
3. Poor diet
4. Chronic kidney failure
Deficiency manifestation:
1. Rickets in kids
2. Osteomalacia in adults - 20Parathyroid Hormone (PTH) (source? regulation? function? causes of decreased serum Mg?)Source:
Chief cells of parathyroid
Regulation
1. (-) serum [Ca] --> inc. PTH
2. (+) serum PO4 --> inc. PTH
3. (-) serum Mg --> inc. PTH
4. (-) (-) serum Mg --> dec. PTH
Function:
1. Inc. bone resorption of Ca and PO4
(receptor activation of NF-kB --> inc. RANKL secretion by osteoblasts --> binds RANK on osteoclasts --> increase bone resorption)
2. Inc. kidney reabsorption of Ca in distal convoluted tubule
3. Dec. reabsorption of PO4 in proximal convoluted tubule
4. Inc. 1,25-OH production by stimulating kidney 1-a-hydroxylase in proximal tubule
Causes of decreased serum [Mg]
1. Diarrhea
2. Aminoglycosides
3. Diuretics
4. Alcohol abuse - 21Calcitonin (source? function? regulation?)Source
Parafollicular cells of thyroid
Function
Dec. bone resorption of Ca
(basically opposes PTH, but not important in normal Ca homeostasis)
Regulation
Inc. serum Ca --> calcitonin secretion - 22Thyroid Hormone (source? regulation? Wolff-Chaikoff? function? TBG synthesis regulation?)(T3/T4)
Source
- Follicles of thyroid
- T3 formed in target tissues via 5'-deiodinase
Regulation
- TRH --> TSH (pituitary) --> follicular cells
- Grave's disease --> stimulation via antibodies
- Negative feedback via T3 and T4
- TBG (thyroid binding globulin) binds most T3 and T4 --> only free T3 and T4 have effects
- Wolff-Chaikoff effect: excess iodine temporarily inhibits thyroid peroxidase --> dec. iodine organification --> dec. T3/T4 production
Function (4B's)
1. Bone growth (synergistic w/ GH)
2. CNS maturation
3. Inc. B1 receptors in heart --> (+) Cardiac output [ (+) HR (+) SV (+) contractility]
4. Inc. basal metabolic rate via Na/K ATPase activity (inc. O2 consumption, respiratory rate, body temperature)
5. Inc. glycogenolysis, gluconeogenesis, lipolysis
TBG synthesis
(+) in:
1. pregnancy
2. OCP use
(-) in:
1. Hepatic failure
2. Steroid use
T3 --> 4 B's: Brain, Bone, B-adrenergic, Basal metabolic rate - 23Thyroid hormone synthesis (note: thyroglobulin, deiodinase, thyroid peroxidase)
- 24Type of hormone: GH? Aldosterone? cortisol? prolactin? ACTH? TSH? FSH/LH? Testosterone? Estrogen? EPi/NE? Insulin? Glucagon? PTH? hCG? T3/T4? Progesterone?GH - protein
Aldosterone - steroid
Cortisol - steroid
Prolactin - protein
ACTH - protein
TSH - glycoprotein
FSH/LH - glycoprotein
Testosterone - steroids
Estrogen - steroids
Epi/NE - tyrosine derivative
Insulin/glucagon - protein
PTH - protein
hCG - glycoprotein
T3/T4 - tyrosine derivative
Progesterone - steroid - 25Signaling pathways of endocrine hormones? - cAMP? -cGMP - IP3 - Intracellular receptor? - RTK? - non RTK --> JAK/STAT pathway
- 26Steroid hormone trafficking in blood (OCPs? pregnancy?)- they're lipophilic --> most are bound to specific binding globulins
- inc SHBG --> dec. free testosterone --> gynecomastia
- dec. SHBG --> free testosterone in women --> hirsutism
- OCPs, pregnancy --> inc. SHBG - 27Cushing Syndrome (etiology? causes? findings?)Etiology
- increased cortisol
Inc. Cortisol due to:
1. Exogenous corticosteroids (--> low ACTH, bilateral adrenal atrophy)
2. Primary adrenal adenoma/hyperplasia (--> low ACTH, atrophy of other adrenal)
3. Pituitary adenoma (Cushing disease)
4. Small cell lung cancer (bilateral adrenal hyperplasia)
5. Bronchial carcinoids (bilateral adrenal hyperplasia)
Findings
1. Hypertension (a1-adrenergic....)
2. Weight gain --> truncal obesity
3. Moon facies
4. Abdominal striae (fibroblast inhibition)
5. Buffalo hump
6. Thinning of skin (fibroblast inhibition)
7. Osteoporosis [(-) bone formation]
8. Hyperglycemia (from insulin resistance)
9. Amenorrhea
10. Immunosuppression - 28Cushing syndrome DiagnosisScreening test (need 2/3):
1. Free cortisol - 24 hr urine
2. Inc. midnight salivary cortisol
3. No overnight low-dose dexamethasone suppression
Then --> measure ACTH
1. If (-) --> adrenal problem OR exogenous glucocorticoids
2. If (+) --> high-dose dexamethasone suppression test + CRH stimulation test
a) if no dexamethasone suppression --> ectopic ACTH secretion OR:
b) if no CRH stimulation --> ectopic ACTh secretion
c) opposite of these two^ --> pituitary adenoma - 29Adrenal insufficiency (symptoms? diagnosis?)Symptoms:
1. Weakness
2. Fatigue
3. Muscle ache
4. Weight loss
5. GI disturbances
6. Orthostatic hypotension
7. Salt cravings
Diagnosis:
A) morning cortisol (should be high) and morning ACTH (should be high):
1) 1* --> low cortisol, high ACTH
2) 2*/3* --> low cortisol, low ACTH
B) ACTH stimulation test
C) metyrapone stimulation test
- metyrapone blocks 11-deoxycortisol --> cortisol
- normal response: dec. cortisol, inc. ACTH, inc. 11-deoxycortisol
1) 1* --> 11-deoxycortisol remains low, inc. ACTH
2) 2*/3* --> ACTH and 11-deoxycortisol remain low after test - 30Primary adrenal insufficiency (etiology? findings? acute causes? chronic causes? findings of 2*/3* cause?)Loss of gland function --> deficiency of aldosterone AND cortisol production -->
1. Hypotension
2. Hyperkalemia
3. Metabolic acidosis
4. Skin and mucosal hyperpigmentation (high POMC)
Acute causes:
1. abrupt withdrawal of glucocorticoids
2. treatment of Cushing syndrome
3. Waterhouse-Friderichsen syndrome
Chronic causes:
1) Addison disease
a) due to autoimmune destruction of adrenal gland (90% or more)
b) OR due to pituitary adenoma
c) OR due to hypothalamic destruction
2) TB/fungal/HIV destruction of adrenal glands
3) metastatic carcinoma from Lung
If 2*/3* cause
- no hyperpigmentation
- normal potassium (aldosterone ok)
- lack of ACTH response w/ metyrapone stimulation test - 31Hyperaldosteronism (what? features? 1* causes? 2* causes?)Inc. secretion of aldosterone from adrenal gland
Features:
1. Hypertension
2. hypokalemia OR normal K
3. Metabolic alkalosis
4. No edema (there's aldosterone escape mechanism)
Primary hyperaldosteronism
1) Adrenal adenoma (Conn Syndrome)
2) Idiopathic adrenal hyperplasia
- findings: (+) aldosterone, (-) renin
Secondary hyperaldosteronism
1. Renovascular hypertension
2. Juxtaglomerular cell tumor
- findings: (+) aldosterone, (+) renin
Use CT to determine etiology
Treatment for bilateral adrenal hyperplasia --> mineralocorticoid receptor antagonist
Treatment for adenoma/carcinoma - surgical resection - 32Neuroblastoma (epidemiology? pathogenesis? findings? lab? classification?)Epidemiology
- most common tumor of adrenal medulla in children
- usually < 4 years old
Pathogenesis:
N-myc oncogene over expression --> originates from neural crest cells --> occurs anywhere along sympathetic chain
Findings:
1. Abdominal distension
2. Firm, irregular mass that can cross the midline (not Wilms tumor, which is smooth and unilateral)
3. Less likely to develop hypertension than pheochromocytoma
4. Can present w/ opsoclonus-myoclonus (dancing eyes, dancing feet)
Lab
1. Inc. HVA (homovanillic acid) in urine
2. Inc. VMA (vanillylmandelic acid) in urine
^both catecholamine metabolites
3. Homer-Wright rosettes (seen in medulloblastoma too)
4. NSE (neuron-specific enolase) pos.
Classified as an APUD (amine precursor uptake decarboxylase) tumor as it may secrete different hormones (hence it's a neuroendocrine tumor)
- 33What is this? epidemiology? possible genetics? symptoms? lab findings? treatment?Pheochromocytoma
Epidemiology
- Most common tumor of the adrenal medulla in adults (from chromaffin cells)
- rule of 10s: (10% malignant, 10% bilateral, 10% calcify, 10% kids, 20% extra-adrenal, 30% familial)
- NF-1, VHL, RET (MEN 2A, MEN 2B)
Symptoms:
secrete epinephrine/NE/dopamine --> 5P's
1. Pressure
2. Pain (headache)
3. Perspiration
4. Palpitations (tachycardia)
5. Pallor
- often relapse and remit
Findings:
- metanephrines (HVA, VMA) in urine and plasma
Treatment
- irreversible a-antagonists (phenoxybenzamine) THEN B-blockers prior to tumor resection
- 34Hypothyroidism/myxedema (signs and symptoms? lab findings?)Signs/symptoms
1. Cold intolerance
2. weight gain despite low appetite
3. hypoactivity/lethargy/fatigue/weakness
4. Constipation
5. Dec. reflexes
6. Hypothyroid myopathy (prox. muscle weakness --> inc. CK)
7. Myxedema (facial, periorbital, from glycosaminoglycan deposits in skin and soft tissue)
8. Dry, cool skin + brittle hair
9. Bradycardia, dyspnea on exertion
10. Oligomenorrhea
Lab findings:
1. Inc. TSH if 1*
2. dec. free T3 and T4
3. Hypercholesterolemia (due to dec. LDL receptor expression) - 35Hyperthyroidism (signs and symptoms? lab findings?)Hyperthyroidism
Signs and symptoms:
1. Heat intolerance
2. Weight loss despite inc. appetite
3. Hyperactivity/insomnia/hand tremor/anxiety
4. Diarrhea
5. Inc. reflexes
6. Thyrotoxic myopathy (proximal muscle weakness, but normal CK)
7. Pretibial myxedema (in Grave's disease)
8. Warm, moist skin + fine hair
9. Chest pain + palpitations, arrhythmias (due to inc. B-adrenergic receptors)
10. staring gaze w/ lid lag
11. Bone resorption w/ hypercalcemia (--> osteoporosis)
Lab findings:
1. Dec. TSH (if 1*)
2. Inc. Free/total T3 or T4
3. Hypocholesterolemia
(due to inc. LDL receptor)
4. Hyperglycemia (from gluconeogenesis, glycogenolysis) - 36Causes of goiter (enlarged goiter....smooth/diffuse causes? nodular causes?)Smooth/diffuse:
1. Grave's disease
2. Hashimoto thyroiditis
3. Iodine deficiency
4. TSH-secreting pituitary adenoma
Nodular
1. Toxic multi nodular goiter
2. Thyroid adenoma
3. Thyroid cancer
4. Thyroid cyst - 37Hashimoto Thyroiditis (epidemiology? causes? findings? histologic findings?)Epidemiology
- most common cause hof hypothyroidism in iodine-sufficient regions
- assoc. w/ HLA-DR5
- inc. risk of non-Hodgkin lymphoma (B origin)
causes:
An autoimmune disease w/:
1. Antithyroid peroxidase (antimicrosomal) antibodies
2. Antithyroglobulin antibodies
Findings:
1. Moderately enlarged NONtender thyroid
2 May be hyperthyroid early on in course (thyrotoxicosis)
Signs Symptoms (another card)
Lab findings:
1. Low T4 and high TSH
Histologic findings:
1. Hurthle cells
2. Lymphoid aggregates w/ germinal centers (hence lymphoma)
- 38Congenital Hypothyroidism (cretinism) (causes? findings?)Causes:
1. Maternal hypothyroidism
2. Thyroid agenesis
3. Thyroid dysgenesis (most common in US)
4. Iodine deficiency
5. Dyshormonogenetic goiter
--> severe fetal hypothyroidism in neonates/infants
Findings (6 P's)
1. Pot-bellied
2. Pale
3. Puffy-faced child w/
4. Protruding umbilicus
5. Protuberant tongue
6. Poor brain development
- 39Subacute granulomatous thyroiditis (de Quervain) (etiology? findings? histology?)Etiology
viral infection/flu-like illness --> self-limited hypothyroid disease --> may be hyperthyroid early on in disease
Findings:
1. Inc. ESR (indicative of inflammation)
2. Jaw pain
3. VERY TENDER thyroid (deQuerVAIN PAIN)
Histology
1. Granulomatous inflammation - 40Riedel thyroiditis (pathogenesis? a manifestation of what? findings?)Pathogenesis
- Thyroid replaced by fibrous tissue w/ inflammation infiltrate --> fibrosis may extend to local structures (trachea, esophagus), mimicking anaplastic carcinoma (but patients are younger)
- 1/3 is hypothyroid
- a manifestation of IgG-related systemic disease:
1. Autoimmune pancreatitis
2. Retroperitoneal fibrosis
3. Noninfectious aortitis
Findings:
1. Fixed, HARD, PAINLESS goiter
- 41Other causes of Hypothyroidism1. Iodine deficiency --> you see a huge thyroid
2. Goitrogens (amiodarone, lithium)
3. Wolff-Chaikoff effect - 42Graves disease (epidemiology? pathogenesis? findings? histology? lab findings? treatment?)Epidemiology
- most common cause of hyperthyroidism
- usually in women of childbearing age
Pathogenesis
- Stress --> thyroid-stimulating immunoglobulin (IgG --> type II hypersensitivity) stimulates TSH receptors on thyroid + dermal fibroblasts
1. Hyperthyroidism
2. Diffuse goiter
3. Pretibial myxedema
- activated T-cells infiltrate retro-orbital space --> (+) cytokines (TNF-a, IFN-g) --> fibroblast secretion of hydrophilic GAGs --> osmotic swelling + muscle inflammation + (+) adipocyte count -->
4. Exophthalmos
Histology
1. Tall, crowded, follicular epithelial cells
2. Scalloped colloid
Symptoms in another card
Lab findings:
1. Inc. total and free T4
2. Dec. TSH
3. Hypocholesterolemia
4. Hyperglycemia
Treatment
1. B-blocker (to block all the upregulated B-adrenergic receptors)
2. Thioamide (blocks peroxidase)
3. Radioiodine ablation
- 43Toxic multinodular goiter- Focal patches of hyperfunctioning follicular cells working independently of TSH
- due to TSH receptor mutations 60% of cases
- inc. release of T3 and T4
- hot nodules are rarely malignant
- 44Thyroid storm (what is it? pathogenesis? presentation? treatment?)- Uncommon, but serious complication
- occurs when hyperthyroidism is incompletely treated/untreated --> significantly worsens in the setting of acute stress (infection, trauma, surgery) w/ inc. catecholamine
Presentation
1. Agitation
2. Delirium --> coma
3. Fever
4. Diarrhea
5. Tachyarrhythmia (death)
6. May inc. LFT
Treat w/ 4P's:
1. Propranolol (B-blocker)
2. Propylthiouracil (PTU - blocks peroxidase AND peripheral conversion of T4 to T3)
3. Corticosteroids (prednisolone)
4. Potassium iodide (Lugol iodine) - 45Jod-Basedow PhenomenonThyrotoxicosis if a patient w/ iodine deficiency and partially autonomous thyroid tissue is made iodine replete
opposite of Wolff-Chaikoff effect - 46what is this? diagnosis via?Thyroid adenoma (follicular adenoma)
Benign SOLITARY growth of the thyroid
- absence of capsular/vascular invasion
- most are nonfunctional
- rarely hot or cold
- most common histology if follicular
- diagnosis via FNA (NO BIOPSY)
- 47what is this? epidemiology and prognosis? risk factors? histology?Papillary carcinoma of thyroid
Epidemiology
- most common thyroid cancer
- excellent prognosis
- often spreads to cervical lymph nodes
Risk factors
- inc. risk w/ RET mutations
- inc. risk w/ BRAF mutations
- inc. risk w/ childhood irradiations
Histology
- Orphan Annie eyes nuclei
- psammoma bodies
- nuclear grooves
Treat w/ thyroidectomy
Complications:
1. Hoarseness (nicking the recurrent laryngeal nerve)
2. Hypocalcemia (removal of parathyroids)
- 48Follicular Carcinoma (how does it behave? prognosis? treatment?)- Invades thyroid capsule and vasculature
- uniform follicles
- hematogenous spread is common
- assoc. w/ RAS mutation
-Good prognosis
- examination with FNA is not enough
Treatment with thyroidectomy
Complications
1. Hoarseness (nicking the recurrent laryngeal nerve)
2. Hypocalcemia (removal of parathyroids) - 49what is this? from what? etiology? histology?Medullary carcinoma
- from parafollicular cells
- produces calcitonin (it's a neuroendocrine tumor)
- sheets /w cells in an AMYLOID stroma
- assoc. w/ MEN 2A, MEN 2B (RET mutation)
- stains Congo red
Treatment with thyroidectomy
Complications
1. Hoarseness (nicking the recurrent laryngeal nerve)
2. Hypocalcemia (removal of parathyroids)
- 50Undifferentiated/anaplastic carcinoma- older patients
- invades local structures --> dysphagia, respiratory compromise
- very poor prognosis - 51Diagnosis of parathyroid disease
- 52Hypoparathyroidism (causes? findings? pseudohypoparathyroidism and pathogenesis? pseudopseudohypoparathyroidism?)causes:
1. Accidental surgical excision of parathyroids
2. Autoimmune destruction
3. DiGeroge syndrome
Findings
1. Tetany
2. Numbness and tingling
3. Hypocalcemia
4. Hyperphosphatemia
5. Chvostek sign (facial nerve)
6. Trousseau sign (BP cuff)
---------------------------------------
Pseudohypoparathyroidism type 1A
(Albright hereditary osteodystrophy)
pathogenesis
- Autosomal dominant inheritance of defective [[Gs protein a-subunit]] from mother
- end-organ resistance to PTH
- inc. PTH but hypocalcemia
Findings:
1. Shortened 4th/5th digits
2. Short stature
--------------------------------------
Pseudopseudohypoparathyroidism
- physical exam features of Albright hereditary osteodystophy
- no end-organ PTH resistance
- occurs when defective Gs protein a-subunit is inherited from father - 53Familial hypocalciuric hypercalcemiaCause
- defective Ca-sensing receptor (CaSR) in multiple tissues:
1. Parathyroids
2. Kidneys
--> higher than normal [Ca] to suppress PTH + excessive renal Ca reuptake --> mild hypercalcemia and hypocalciuria w/ normal to inc. PTH level - 54Primary hyperparathyroidism (due to? presentations? lab findings?)Due to:
1. Parathyroid adenoma
2. Parathyroid hyperplasia
3. Parathyroid carcinoma
Presentations
1. Weakness and constipation (groans)
2. Abdominal pain/flank pain
2a - nephrolithiasis, nephrocalcinosis
2b- acute pancreatitis
2c - peptic ulcer
3. Depression + seizures
4. Osteitis fibrosa cystica (cystic bone spaces filled w/ brown fibrous tissue - osteoclasts + deposited hemosiderin from hemorrhages --> bone pain)
"stones, bones, groans, and psychiatric overtone"
Lab findings:
1. Hypercalcemia
2. Hypercalciuria (stones)
3. Hypophosphatemia
4. Inc. PTH
5. Inc. Alk Phos
6. Inc. cAMP in urine - 552* hyperparathyroidism? 3* hyperparathyroidism? (pathogenesis for both? complications?)2* hyperparathyroidism
chronic renal disease --> hypovitaminosis D --> dec. Ca absorption and/or inc. PO4 in serum --> low [Ca] --> stimulates all 4 parathyroid glands --> 2* parathyroid hyperplasia
Lab findings:
1. Hypocalcemia
2. Hyperphosphatemia
3. Inc. Alk Phos
4. Inc. PTH
Complications
1. Renal osteodystrophy (bone lesions)
-----------------------------------------------------
3* hyperparathyroidism
Chronic renal disease --> refractory (autonomous) hyperparathyroidism -->
1. (+) (+) PTH
2. (+) Ca
Complications:
1. Renal osteodystrophy (bone lesions) - 56What is it? prognosis? symptoms? treatment?Pituitary adenoma
- benign tumor of anterior pituitary cells
- if nonfunctional --> mass effect:
1. Bitemporal hemianopia
2. Hypopituitarism
3. Headache
- if functional --> depends on the hormone produces
1. Prolactinoma (most common)
a) galactorrhea
b) amenorrhea
c) decreased libido
2. Growth hormone cell adenoma
a) gigantism in children
b) acromegaly in adults
c) secondary diabetes (GH inc. glucose)
3. ACTH cell adenoma
a) Cushing syndrome
Treatment:
1. Dopamine agonists (bromocriptine, cabergoline)
2. Transsphenoidal resection
- 57Nelson syndrome (pathogenesis? presentation? treatment?)Refractory Cushing disease --> bilateral adrenalectomy --> no neg feedback, so enlargement of existing ACTH-secreting pituitary adenoma
Presentation
1. Hyperpigmentation
2. Headaches
3. Bitemporal hemianopia
Treatment:
1. Pituitary irradiation
2. Surgical resection - 58Acromegaly (due to what? findings? diagnosis? treatment?)Due to excess GH in adults, typically caused by pituitary adenoma
Findings:
1. Large tongue w/ deep furrows
2. Deep voice
3. Large hands and feet
4. Coarsening of facial features w/ aging
5. Frontal bossing
6. Diaphoresis
7. Impaired glucose tolerance
8. Visceral enlargement --> HF = cause of death
Diagnosis
1. Inc. serum IGF-1
2. Failure to suppress serum GH following oral glucose tolerance test
3. Pituitary mass seen on brain MRI
Treatment
1. Pituitary adenoma resection
2. If not cured --> treat w/ octreotide
3. If not cured --> treat w/ pegvisomant (GH receptor antagonist) - 59Laron syndrome (dwarfism) (cause? lab findings? clinical features?Cause:
- defective growth hormone receptors --> dec. linear growth
Lab findings:
1. Inc. GH
2. Dec. IGF-1 (since defective growth hormone receptors)
Clinical features
1. Short height
2. Small head circumference
3. Characteristic facies w/ saddle nose and prominent forehead
4. Delayed skeletal maturation
5. Small genitalia - 60Central Diabetes Insipidus (causes? findings? symptoms? test? treatment?)Causes:
1. Pituitary tumor
2. Autoimmune destruction of pituitary
3. Trauma
4. Surgery
5. Ischemic encephalopathy (sheehan's)
6. Idiopathic
Findings:
1. Dec. ADH
2. Urine specific gravity < 1.006
3. Serum osmolality > 290 mOsm/kg, hypernatremia
4. Hyperosmotic volume contraction
Symptoms:
1. Intense thirst
2. Polyuria
Water deprivation test:
1. > 50% inc. in urine osmolality only after administration of ADH analog
Treatment
1. Desmopressin acetate
2. Hydration - 61Nephrogenic Diabetes Insipidus (etiology? findings? test? treatment?)Etiology
1. Hereditary (ADH receptor mutation)
2. 2* to hypercalcemia
3. 2* to hypokalemia
4. 2* to lithium
5. Demeclocycline (ADH antagonist)
Findings:
1. Normal/inc. ADH levels
2. Urine specific gravity < 1.006
3. Serum osmolality > 290 mOsm/Kg
4. Hyperosmotic volume contraction
water deprivation test:
1. Minimal change in urine osmolality even after administration of ADH analog
Treatment
1. Hydrochlorothiazide
2. Indomethacin
3. Amiloride (for Li-induced DI)
4. Hydration - 62SIADH (causes? characteristics? complications? treatment?)Causes:
1. Ectopic ADH (small cell lung cancer)
2. CNS disorders/head trauma
3. Pulmonary disease
4. Drugs (cyclophosphamide)
Characteristics:
1. Excessive free water retention
2. Euvolemic hyponatremia w/ continued urinary Na excretion (since water retention --> dec. aldosterone, inc. ANP, inc. BNP --> inc. urinary Na secretion --> normalization of extracellular fluid volume --> euvolemic hyponatremia)
3. Urine osmolality > serum osmolality
Complications (due to low Na)
Cerebral edema --> seizures
Treatment
1. Fluid restriction
2. Salt tablets
3. IV hypertonic saline (correct slowly to avoid osmotic demyelination syndrome)
4. Diuretics
5. Conivaptan
6. Tolvaptan
7. Demeclocycline - 63Hypopituitarism (what is it? causes? treatments?)Undersecretion of pituitary hormones
Causes:
1. Nonsecreting pituitary adenoma
2. Craniopharyngioma (in children)
3. Sheehan syndrome (ischemic infarct of pituitary due to postpartum bleeding --> no milk, cold intolerance, etc)
4. Empty sella syndrome (atrophy/compression of pituitary --> common in fat women)
5. Pituitary apoplexy (sudden hemorrhage into existing pituitary adenoma --> destruction of pituitary --> sudden headache + visual deficits)
6. Brain injury
7. Radiation
Treatments
- hormone replacement (basically everything) - 64Diabetes Mellitus (acute manifestations? diagnosis?)Polydipsia --> polyuria
Polyphagia
Weight loss
Diabetic ketoacidosis (if type 1)
Hyperosmolar coma (if type 2)
seen in patients on glucocorticoid therapy
---------------------------------------
Diagnosis
1. HbA1C > 6.5% (reflects average blood glucose over prior 3 months) (5.7-6.4% is prediabetic)
2. Fasting plasma glucose > 126 mg/dL (> 100 mg/dL is pre diabetic)
3. 2-hr oral glucose tolerance test (> 200 mg/dL) (> 140 mg/dL is prediabetic) - 65Diabetes Mellitus (chronic complications)Nonenzymatic glycation + osmotic damage (glucose --> ALDOSE REDUCTASE --> sorbitol) -->
A) small vessel disease (diffuse thickening of basement membrane)
1. retinopathy:
- non-proliferative: due to exudates and microaneurysm
- proliferative: due to hypoxia --> inc. VEGF --> proliferation of vessels --> hemorrhages
2. glaucoma --> retinal detachment --> blindness
3. Diabetic neuropathy (peripheral sensory and motor, glove and stocking distribution) --> decreased sensation --> imbalanced footing --> ulcer, but one doesn't feel it --> gangrene --> amputation
4. Nephropathy - nodular glomerulosclerosis (kimmelstiel-wilson nodules --> progressive proteinuria --> use ACE-i)
5. Nephropathy - arteriolosclerosis (leads to hypertension --> chronic renal failure)
B) Large vessels:
6. Atherosclerosis
7. Coronary artery disease
8. Peripheral vascular occlusive disease
9. MI (most common cause of death)
C) cataracts
D) autonomic degeneration (neuropathy) - 66Diabetes mellitus (illustration of stuff)
- 67Diabetes (type 1 vs 2)
- 68Diabetic ketoacidosis (due to? pathogenesis? symptoms? lab? complications? treatment?)Due to:
1. Insulin noncompliance in type I
2. (+) stress --> epinephrine --> glucagon stimulated --> inc. lipolysis (w/ no insulin to stop glucagon)
Pathogenesis:
Excess fat breakdown --> ketogenesis from free fatty acids --> made into ketone bodies (B-hydroxybutyrate, acetoacetate, acetone)
(endogenous insulin in Type 2 is protective)
Symptoms:
1. Delirium/psychosis
2. Kussmaul respiration (to expire more to get rid of CO2 to balance out pH)
3. Abdominal pain/nausea/vomiting
4. Dehydration (polyuria, etc)
5. Fruity breath/odor
Lab:
1. Hyperglycemia
2. Anion gap metabolic acidosis
3. Inc. blood ketone levels
4. Leukocytosis
5. Hyperkalemia (but depleted intracellular K, since no insulin)
Complications
1. Life-threatening mucormycosis (Rhizopus infection)
2. Cerebral edema
3. Cardiac arrhythmias (due to hyperphosphatemia)
4. Heart failure
Treatment
1. IV fluids + K and later glucose
2. IV insulin - 69Hyperosmolar hyperglycemia nonketotic syndrome (epidemiology? pathogenesis? symptoms? complications? labs? treatment?)- classically seen in elderly type 2 diabetics
Pathogenesis
Hyperglycemia --> excessive osmotic diuresis --> dehydration
symptoms:
1. Thirst
2. Polyuria
3. Lethargy
4. Focal neurological deficits (seizures)
Complications:
1. Coma and death if untreated
Labs:
1. Hyperglycemia (> 600 mg/dL)
2. Inc. serum osmolality (> 320 mOsm/kg)
3. No acidosis (pH > 7.3)
Treatment
- aggressive IV fluids
- insulin therapy - 70Glucagonoma (what is it? presentation? treatment?)Tumor of pancreatic a-cells --> overproduction of glucagon
Presentation (5 D's)
1. Dermatitis (necrolytic migratory erythema)
2. Diabetes (hyperglycemia)
3. DVT
4. Declining weight
5. Depression
Treatment
1. Octreotide
2. Surgery - 71Insulinoma (pathogenesis? classical symptoms? strange symptoms? lab? treatment?)Pathogenesis
Tumor of pancreatic B-cells --> overproduction of insulin --> hypoglycemia
Whipple triad:
1. Low blood glucose
2. Symptoms of hypoglycemia (lethargy, syncope, diplopia)
3. Resolution of symptoms after normalization of glucose levels
- would see acanthosis nigricans (as insulin cross reacts with melanocyte receptors)
Lab:
1. Hypoglycemia
2. Inc. C-peptide
10% cases assoc. w/ MEN 1 syndrome
Treatment
1. Surgical resection - 72Somatostatinoma (pathogenesis? presentation? treatment?)Tumor of pancreatic D-cells --> overproduction of somatostatin --> dec secretion of:
1. Secretin
2. Cholecystokinin
3. Glucagon
4. Insulin
5. Gastrin
Presentation:
1. Diabetes/glucose intolerance
2. Steatorrhea
3. Gallstones
Treatment
1. surgical resection
2. Somatostatin analogs - 73What is this? pathogenesis? symptoms? lab diagnosis? treatment?rare syndrome caused by carcinoid tumors (neuroendocrine cells), esp. metastatic small bowel tumors --> secrete high amounts of serotonin (5-HT)
- not seen if tumor is limited to GI tract
Symptoms:
1. Recurrent diarrhea
2. Cutaneous flushing
3. Asthmatic wheezing
4. Right-sided valvular heart disease (tricuspid regurgitation, pulmonic stenosis)
Lab diagnosis
1. inc. 5-hydroxyindoleacetic acid (5-HIAA) in urine
2. Niacin deficiency (since it's most likely a small bowel tumor --> malabsorption)--> (pellagra - diarrhea, dermatitis, dementia)
Treatment
1. Surgical resection
2. Somatostatin analog
Rule of 1/3:
1. 1/3 metastasize
2. 1/3 present w/ 2nd malignancy
3. 1/3 are multiple
- most common malignancy in the small bowel
- 74Zollinger-Ellison syndrome (what is it? pathogenesis? presentation? test?)Gastrin-secreting tumor of pancreas/duodenum
Pathogenesis
Acid hyper secretion --> recurrent ulcers in duodenum and jejunum
Presentation
1. Abdominal pain (PUD, distal ulcer)
2. Diarrhea
Test:
1. Positive secretin stimulation test (gastrin level remain high after administration of secretin, which should inhibit gastrin)
2. May be assoc. w/ MEN 1 - 75Multiple Endocrine Neoplasia (each one and their presentations and genetic mutations)Autosomal dominant inheritance
MEN 1
- mutation of MEN1 (menin, a tumor suppressor. chromosome 11)
- pituitary tumors (prolactin/GH)
- Pancreatic endocrine tumors (Zollinger-Ellison, insulinomas, VIPomas, glucagonomas)
- Parathyroid adenomas
MEN 2A
- RET mutation in cells of neural crest origin
- Parathyroid hyperplasia
- Medullary thyroid carcinoma (parafollicular/C cells)
- Pheochromocytoma
MEN 2B
- mutations in RET gene
- Pheochromocytoma
- Medullary thyroid carcinoma
- Mucosal neuromas (oral/intestinal ganglioneuromatosis)
- 76Oxytocin- mediates uterine contraction during labor
- release of breast milk in lactating mothers - 77Pseudohyperaldosteronism (syndromes)Liddle syndrome
- Autosomal dominant
- decreased. degradation of ENaC sodium channels in collecting tubules
Presentation:
1. CHILD w/ hypertension + hypokalemia + metabolic alkalosis
2. Low aldosterone + low renin
Treatment
- Potassium sparing diuretics (amiloride, triamterene) --> block tubular Na channels
-----------------------------
syndrome of apparent mineralocorticoid excess (SAME)
- 11-B-hydroxysteroid dehydrogenase 2 deficiency (AR) --> cortisol isn't broken down --> activates mineralocorticoid receptors too
- May also arise w/ licorice
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- Organ modules Flashcards on Endocrine, created by Eric Zhang on 01/04/2017.
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- Eric Zhang
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