Endocrine Flashcards
(116 cards)
1
Q
Thyroid Development
A
- Deriative of floor of ectoderm, descends along thyroglossal duct to sit in anteior midline.Foramen Cecum
- Thyroid along duct leads to pyramidal lobe
- Ectopic thyroid is located at base of tongue
2
Q
Thyrglossal duct cyst
A
- Located anterior midline and moves with swallowing
- Branchial cleft cysts are located laterally
3
Q
Fetal Adrenal Gland
A
- Contains fetal part that secretes sex steroids
- Adult part which secretes Cortisol under influence of fetal ACTH.
- Cortisol is crucial for lung development and surfactant production
4
Q
Zona Glomerulosa
A
-Most cortical, secretes aldosterone in response to renin-angiotensin 2
5
Q
Zona Fasicularis
A
-Secretes coritsol in response to ACTH/CRH
6
Q
Zona Reticularis
A
-Secretes Sex steroids, also increased by ACTH and CRH
7
Q
Adrenal Medulla
A
-Contains NC derived chromafin cells (S-100 +) that secrete Epi (some nor epi, 10%) in response to Ach releaased from preganglionic sympathetics that branch from IML at T10-L1 and travel along splanchinics
8
Q
Pheochormocytoma
A
- Tumor of adrenal medulla in adults causes episodic HTN
- Located with MBIG scan which will detect location of ectopic caetacholamine synthesis
9
Q
Neuroblastoma
A
Kids
- Most common location is adrenal medulla, does not cause episodic HTN Most common extracranial mass in childhood
- MBIG scan will localize ectopic caetacholamine secretion.
- Can spread and involve any location along sympathetics or elsewhere
- Increased risk with NF-1 and Beckwith wiederman
10
Q
Arterial Supply of Adrenal
A
- Superior adrenal off phrenic
- Middle adrenal off aorta
- Inferior adrenal off Renal
11
Q
Venous Drainage
A
- L: Adrenal drains dircetly into IVC
- R: Adrenal drains to renal the to IVC
12
Q
Posterior Pituitary
A
- Derivative of neuroectoderm
- Recieves inputs from magnocellular neurons that originate in supraoptic and paraventricular hypothalamus. (near disrutpion in BBB called OVLT that senses osmolality)
- Secretes ADH and Oxytocin, carried along magnocellular neurons by neurophysin
13
Q
Anterior Pituitary
A
- Derivative of surface ectoderm (Rathkes pouch)
- Acidophilic cells: GH and Prolactin
- Basophilic: FSH, LH, ACTH, TSH
- TSH, FSH, LH, HCG have similiar alpha subunit, beta subunit determines specificity
14
Q
Endocrine Pancreas
A
Islets of langerhans
- Alpha (glucagon) Peripherally located
- Beta (insulin) Centrally located
- Delta (somatostatin) Interspersed
15
Q
Insulin Physiologic Release
A
-Elevated glucose enters beta cells through Glut-2 which is high capacity but low affinity. Increase glucose leads to increase ATP. Elevated ATP closes K channel leading to depolarization, opening of V-gated Ca channels which signal release of insulin.
16
Q
Insulin Secreted hormonally
A
- Beta 2 increases insulin secretion
- Glucagon stimulates Gs which also increases insulin secretion
- GH also increases insulin secretion
17
Q
Insulin sepressed hormonally
A
- Supressed by alpha 2 stimulation
- Also suppressed by somatostatin
18
Q
Glut -1
A
Insulin independent
- Enriched in brain and RBC
- Low capacity and high affinity (basal levels take up)
19
Q
Glut - 2
A
- Insulin independent
- Increased in Liver, Beta Cells, Kidney, Small intestine.
- Low affinity but high capacity. With high glucose levels large quantities will enter cells
- Responsible for insulin secetion and for bringing glucose levels down after meal
20
Q
Glut - 4
A
Insulin Dependent
- Enriched on skeletal muscle and adipose (Storage depots)
- also present on cardiac tissue
21
Q
Insulin effects on electrolytes
A
- Causes increase in Na/K ATPase which brings K in and decreases extracellular K
- Causes Na retention by kidney
22
Q
Proinsulin
A
Secreted as disulfide bridged dimer with C peptide
-Can be used to see if insulinoma or facticous
23
Q
Glucagon
A
-Released from alpha cells in response to hypoglycemia
24
Q
Theraputic uses of glucagon
A
-Can be used to treat beta blocker overdose. Both are Gs receptors
25
TRH effects
-Causes release of prolactin and TSH
26
Prolactin
-Inhibits GnRH
27
CRH
Causes release of POMC
28
Prolactinoma effects
- No periods while breast feeding
| - Amenorrhea with PRL secreting tumor
29
Prolactin Functions and regulation
- Causes increaed milk production in female
- Inhibits GnRH leads to no periods during breast feeding, amenorrhea, no spermatogenesis
- Inhibited by dopamine (severe stock leads to increase)
- Stimulated by estrogen (OC) and TRH (hypothyroid)
- Prolactincomas treated with dopamine agonists (pergolide, bromocriptine)
- Antipsychotics (dopamine antagonists) and OC can cause galactorrhea
30
GH
- Produced by aciophils in AP
- Stimulated by GHRH
- Inhibited by high glucose and somatostatin
- Causes the release of IGF-1 from liver which stimulates linear growth
- Tumor leads to gigantism in kids and acromegally in adults. (most commonly die of Heart Failure)
- Test with glucose supression and can also measure IGF-1 levels
- Tumor treated with somatostatin analog octreotide
31
Adrenal steroid production
- Begins at cholesterol. Desmolase is rate limiting step which produces pregnenalone. Desmolase increased by ACTH and inhibited by ketocolanazole
- 17 hydroxylase makes sex steroids an cortisol
- 21 hydroxylase makes cortisol and aldosterone
- 11 hydroylase makes cortisol and aldosterone
- Angiotensin 2 stimulates aldosterone synthase
- CAH is absence of one of these enzymes which leads to hypersecrtion on ACTH from low cortisol levels leading to enlarged adrenals
32
17 Deficency
- Leads to impaired sex and cortisol production with elevated aldosterone production
- Hypotension with hyperkalemia
- Female will show lack of secondary sex characteristics
- Male will have pseudohermaphroditism
33
21 Deficency
- Will have loss of aldosterone, 11-DOC, and cortisol
- Hypotension, hyperkalemia and masculinization
- Females will show pseudohermaphroditism
34
11 Deficency
- Will have loss of aldosterone and cortisol with incerase in sex and 11-DOC
- Leads to HTN (11-DOC) and masculinization
35
Growth Factor Receptors
JAK-STAT
36
IP3
GHRH, Oxy, GnRH, TRH
37
Cortisol
- Zona fasiculatis
- Increased with ACTH
- Causes: Increased alpha 1 expression, hyperglycemia, inhibits fibroblasts, decreases bone mineral density, inhibits immune response (loss IL-2 and apoptosis)
- Lipocortin inhibits PLA-2
- Carried on CBG, glucuronidation leads to renal excreition, can be measured with 24 hr cortisol in urine.
38
PTH
Released from Parathyroid chief cells
- Causes increase in serum Ca and loss of phosphorus
- Increases bone resoprtion (stimulate RANK-L on blasts, also stimualte m-CSF to increase clasts (monocyte lineage)
- Increase 1 alpha hydroxylase in kidney to increase vitamin D active form
- Increase renal loss of phosphorus and increase renal absorption of Ca
- Stimualted by decrease in Ca and Mg
- Inhibited by massive decrease in Mg (diuretics, alcohol, diahrrea)
39
Vitamin D (Cholecalciferol)
- Produced in skin from cholesterol by UVB as D3 and dietary as D2
- Sent to liver where converted to 25-OH form that is active storage form.
- Kidney will metabolize with 1-alpha hydroxylase to active 1,25 form.
- 25,24 form is inactiv
- Funtions to increase Ca and Phosphate resportion in gut.
- Production stimulated by low levels of Ca and P
- Deficency in childhood leads to rickets and osteomalacia in adults
40
Calcitonin
- Causes decreased bone resportion and increased bone deposition of Ca leading to decreaesed levels of blood Ca
- Stimulated by elevated Ca
41
NO
cGMP signalling Mechanis
42
ANP
cGMP signalling mechanism
43
Releasing hormones besides CRH
IP3 signalling mechanism
44
ADH V1 and Oxytocin
IP3
45
Ang 2
IP3
46
Growth Factors
RTK and MAPK
47
PRL and GH
JAK/STAT receptor associate TK
48
Cytokines
JAK/STAT
49
Steroid Horomone Binding Globulins
- Increasd by estrogens (OC and pregnancy)
- Decreased by androgens
- Sequester steroid homones and decrease effective concentration
- Also decreasd with cirrhosis
50
Thyroid Hormone Physiologic Functions
- T3 is more active than T4, peripheral 5' deiodinase
- Increase B1 receptors (Heart function increased)
- Inrease BMR through increase Na/K ATPase
- Cause hyperglycemia (increase glucose production)
- Necessary for bone and brain development (cretinism)
51
Thyroid Hormone regulatio
- TRH from hypothalamus increases PRL and TSH release
- TSH stimulates T3/T4 release increase thyroid peroxidase activity
- Free T3 causes decreased sensitvity to TRH at level of AP
52
Thyroid Hormone Production
- Thyroid peroxidase perfoms oxidation, organification, and coupling of iodone to thyroglobulin (tyrosine)
- T4 is main secreted hormone, changes to T3 peripherally with 5' deiodinase, T3 binds Receptor tighter
53
Wolf Chiakoff Effect
-Elevated iodine causes a transient decrease in thyroid production
54
Propylthiouracil
-Causes decrease in thyroid peroxidase activity and decrease in peripheral function of 5' deiodinase
55
Methimazole
-Inhibits thyroid peroxidase
56
Cushings Syndome Symptoms
- Weakness, used for GNG
- Striae-Coristol inhibits fibroblasts
- HTN: Induce alpha 1 receptors
- Osteoporosis
- Immunosupression: (Apoptosis, decerase IL-2, decrease histamine, block PLA-2)
- Fat deposits
- Hyperglycemia
- Amenorrhea
57
-Cushings Causes
- Iatrogenic: Leads to bulateral atrophy of adrenal glands
- Tumor or hyperplasia of adrenal gland leading to unilateral enlargment and unilateral atrophy
- ACTH tumor (Cushings disease) Bilateral hyperplasia of adrenals. Cortisol will be supressed with high dose dexamethasone supression
- ACTH tumor paraneoplastic: No supression. Most commonly Lung (small cell or bronchial carcinoid)
58
Cushing Dx
- Symptoms
| - ELevated 24 hr urine with glucuronidated cortisol
59
Primary Chronic Hypoaldosteronism (Addisons)
- Decreased aldosterone, and cortisol from adrenal hypoplasia
- Most commonly autoimmune, can be TB and also metastasis from lungs
- Adrenoleukodystrophy also
- Symps: Hypotension, Hyponatremia, Hyperkalemia, Acidosis. Skin hyperpigmentation from POMC
60
Secondary Chronic Hyperaldosteronism
- Decreae pituitary ACTH: Tumor
| - Same symptoms without skin changes
61
Acute adrenal insuficcency
- Nisseria Meningitidis causes waterhouse freidrichson or acute hemorrhagic infarction of adrenals bilaterally
- DIC and loss of cortisol often fatal
62
Primary Hyperaldosteronism (Conn's)
- Caused by tumor or hyperplasia of adrenals.
- Leads to hypertension, Hypernatremia, Hypokalemia, Alkalosis.
- Renin levels will be low
- Tx: Surgery and spironolactone
63
Secondary Hyperaldosteronism
- Elevations in RAS lead to hyperaldosterone.
- Same symtoms with an elevated Renin
- Renal artery stenosis, fibromuscular dysplasia, atherosclerois, CHF, anything that will lead to decreased renal perfussion.
- Ang II activates aldosterone synthase
- Tx: Spironolactone
64
Adrenal Crisis
- Hypotension and volume contraction due to adrenal failure
| - Can be caused when steroid therapy is rapidly removed because of adrenal atrophy that has occured.
65
Pheochromocytoma
- Tumor of the adrenal medulla. NC cells that are S-100 +
- Recieve input from primary sympathetics with Ach the NT
- Release of Epi, Norepi, and Dopamine leads to episodic HTN, palpitations, heacache and SANS signs (Skin pallor)
- Dx with elevated serum metanephrines and elevated urinary VMA, product of MAO metabolism. (HVA more specific for neuroblastoma in kids)
- MIBG scan can show ectopic locations, commonly bladder
- Associated with: NF-1 (AD oncongene), VHL, MEN2 (medullary thyroid and pheo are necessary, RET)
- Tx: Alpha and beta blockade. Surgery must be performed after administration of phenoxybenzamine
66
Caetacholamine synthesis
- Phenylalanine to tyrosine (phenylalanine hydroxylase)
- Tyrosine to L-DOPA (THB and tyrosine hydroxylase)
- L-DOPA to Dopamine (B6, Dopa decarboxylase)
- Dopamine to Noreip (Vitamin C, Dopamine decarboxylase)
- Norepi to Epi (SAM, Phenylethanolamine-N-Methyl Transferase)
67
THB
- Deficency will cause atypical phenylketonuria
- Impaired caetacholamine synthesis and NO metabolism
- Made from GTP endogenously
68
Neuroblastoma
- Most common extraranial mass in kids.
- Most often presenst as abdominal mass, and is less likely associated with HTN
- Leaks dopamine, Nor/epi, test urinary HVA
- Localize with MBIG scan, most commonly in adrenal medulla but can be other places
- Overexpression of N-Myc
- Associated with NF-1 and Beckwith-Wiederman
69
Hypothyroid Clinical Manifestations
- Cold intolerance, bradychardia, diastolic HTN, Constipation, slowed reflexes, depression
- Facial and periorbital myxedema
- Hypercholesteroemia and hypoglycemia
- Yellowing of skin because T3/4 necessary for beta carotene metabolism
- May cause elevations in TRH leading to increased PRL and oligo or amenorrhea
70
Myxedema Coma
Decompensated hypothyroidism generally brought on by stress.
- Severe hypotension, bradychardia, resp depression and decreased temp
- Treat with thyroid, cortisol, warming.
71
Hashimotos
- Auto antibodies to thyroglobulin or thyroid peroxudase. Associated with HLA-DR5
- May present early as hyperthyroid but eventually becomes hypothyroid
- Moderately enlarged and nontender thyroid
- Lymphocytic infiltrate with germinal centers that predispose to marginal zone lymphoma
- Hurthle cells, large eosionphilic cells around colloid
72
Cretinism
- Congenital and perinatal severe insufficency of thyroid
- Most commonly because of iodine deficency and endemic goiter, but is rarely caused by congenital thyroid structural or funcional mutations
- Retardation and decreased stature. Born with large tongue, large belly, and omphalocele/umbilical hernia
- Retardation because thyroid is necessary for synapse formation and also for bone growth
73
Dequarvians subacute thyroiditis
- Granulomatous inflammation (type 4) following viral illness
- Thyroid status may be hyper/hypo/eu
- Painful goiter! with elevated ESR and associated jaw pain
- Self limited
74
Ridels Thyroiditis
- Fibrous replacement of thyroid tissue. Thought to be related to IgG4 systemic fibrosing diseases
- Will cause hypothyroidism signs and a rock hard painless thyroid
- Often has extension into the local laryngeal structures possibly compromising speaking and breathing.
- Differntiate from anaplastic carcinoma, occurs mainly in younger females.
75
Goiter
Most common cause is goiter which is caused by a lack of iodine leading to impaired thyroid production causing and increase in TSH which is trophic for the thyroid
-Increased ratio of free T3/T4
76
Toxic Multinodular Goiter
- Idiopathic focal hyperplasia of thyroid nodules. Will present with a non uniformal enlargment and hyperthyroidism.
- Accumulated mutation in TSH gene that causes TSH independent production
- Can detect hot nodules with RIA. Cancer is hypothyroid and will be cold on RIA
77
Jon Basedow phenomenon
-Patients with long term iodine deficency and goiter may become hyperthyroid after replacement of iodine because of hyperplasia
78
Graves Disease
- TH2 hypersensitivity with TSI autoantibodies to TSH receptor leading to hyperthyroidism
- Diffuse nontender goiter that will show enlarged follicles with colloid scalloping on histology
- Will show pretibial myxedema because TSI stimulates fibroblasts
- Tx: Methimazole and PTU
79
Hyperthyroidism
- Increase in BMR due to increased Na/K ATPase activity
- Increase in B1 expression and subsequent hypersensitivity to caetacholamines
- Pretibial myxedema (graves, TSI)
- Arrythmias, tachychardia, hypocholesterolemia, hyperglycemia
- Diahrrea
- Staring gaze because of SANS activation of levator palpebrae superioris
- Labs will show elevations in T3 and T4 with reductions in TSH. May also show elevated ALP because of increased bone turnover
80
Thyroid Storm
- Extreme increase in thyroid production and serious consequences.
- Generally arises in the context of stress because of elevations in caetacholamine release
- Death most likely by arrythmia
- Treat with beta blockers, iodine (wolff-Chiackoff) and PTU (5'deiodinase)
- Increased ALP often seen
81
Thyroid cancer
Generally focal enlargment, not diffuse
- generally non functional and will be cold on RAI
- If treated with T3/T4 before surgery there will be decrease in TSH and shinkage of gland for easier surgery
82
Papillary Carcinoma
- Most common type of carcinoma greater than 80%
- Linked to early exposure to radiation (acne irradiation)
- Focal enlargment
- FNA will show cells with pale nuclei (orphan annie) and nuclear grooves
- Will also show psammoma bodies (papillary carcinoma)
83
Follicular Carcinoma
- 2nd most common cause and can be adenoma or carcinoma
- Encased by fibrous sheath, and is ademona if not through sheath and carcinoma if it is.
- Spreads hematogenously (RCC, HCC, Choriocarcinoma also)
84
Medullary Thyroid Carcinoma
- Carcinoma of parafollicular C cells that secrete calcitonin
- Tumor cells in an amyloid stroma. Amyloid from calcitonin secretion
- Seen in all cases of MEN2 A and B. Also both have pheo.
- 2A: parathyroid
- 2B: Neruofibromas
85
Anaplastic
- Highly malignant and seen most comonly in elderly
- Poorly differentiated spindle cells
- Hard shrunken thyroid that often invades local structures causing breathing problems or speaking problems.
- Differentiate from riedels mainly on age of patient
86
Marginal Zone B Cell Lymphoma
-Seen in Hashimotos thyroiditis where germinal centers form in thyroid and give rise to marginal zone lymphomas.
87
Primary Hyperparathyroidism
Most commonly and adenoma, but can also be carcinoma (MEN2)
- Elevations in PTH lead to hypercalcemia and hypophosphatemia.
- PTH only responds to free Ca (not complexed with albumin or phosphate)
- PTH activates Osteoblasts to express RANK-L to activate osteoclasts
- Increased ALP, bone pain, constipation, Renal stones, dystrophic calcification (nephrocalcinosis)
- cAMP urine test, PTHR is Gs which means stimulation will cause elevations in urinary cAMP
- Siezures and weakness
- Polyuria
- Cardiac Arrest!
88
Secondary HyperPTH
- Most often caused by renal failure that leads to calcium wasting, phosphate retention, and inability to produce vitamin D
- Low Ca with High PTH
- Phosphate will also be raised which will further decrease free Ca
89
3 hyperPTH
- End organ resistance to PTH or autonomous PTH secretion from PTH gland
- Generally occurs in the context of renal disease
- Elevations in PTH and elevations in Ca
90
Osteitis Fibrosa Cystica
Elevations in PTH will cause increased bone destruction and replacement with fibrous tissue.
- This can cause bone pain
- Most commonly associated with primary hyperPTH
91
Renal Osteodystrophy
-Renal failure that lead to increased PTH that causes excessive bone breakdown.
92
HypoPTH
- Most commonly caused by surgica error
- Digeorge, autoimmune distruction
- Presents with hypocalcemia and not increase in PTH
- Muscle spasm and perioral tingling
93
Pseudohypoparathyroidism
- Congenital malfunction in Gs portion of PTH receptor that leads to renal non-responsiveness
- Short stature and shortened 4th and 5th digets in the context of elevated PTH and decreased Ca
94
PTHrP
- Paraneoplastic syndrome that causes incerases in Ca
- most commonly breast and squamous cell lung
- Ca is also often increased in cancer for other reasons.
95
Pituitary Adenoma
Most commonly nonfunctional causing mass effect: Headache, panhypopit, bitemporal hemianopsia
96
Prolactinoma
- Most common functional of pituitary
- Causes galactorrhea and amenorrhea in women and decreased libido and decreased sperm in men (inhibit GnRH)
- Tx with pergolide or bormocriptine
- Can be mimicked by antipsychotics (dopamine antagonists)
97
GHoma
Second most common
- Acromegally in adults and gigantism in kids
- Increased IGF-1, also will not respond to glucose supression test
- Hyperglycemia and organomegally
- most common cause of death is cardiomegally and CHF
- Treatment with resection or octreotide
98
Diabetes Insipidus
- Impaired signalling and fuction of ADH leading to increased urine output, polydypsia and hyperoslmolarity
- ADH works on collecting ducts and distal tubule late
99
Central DI
- Decreased ADH production
- Will improve with Desmopressin administration
- Caused: Tumor (craniopharyngoma, Trauma, histiocytosis)
100
Nephrogenic DI
- Kidney doesn't respond to ADH
- Doesn't improve with desmopressin
- Commonly caused by Lithium (Tx amiloride), congenital
- Tx: Hydrocholorothiazide, indomethacin, both decrease renal perfusion , decreased GFR increase retention
101
SIADH
- Elevated secretion of ADH leading to hypervolemia and dilutional hyponatremia
- Can present with mental status changes and siezures
- Caused by lung pathology: Small cell carcinoma, Legionella, COPD
- Caused by drugs: Cyclophosphamide, Trauma
- Correct Na slowly
- Treat with conivaptan or demeclocycline to block ADH.
102
Craniopharyngoma
-Tumor of rathkes pouch that can cause hypopituitarism
103
Sheehan's Syndrome
- Growth of AP during pregnancy and hypotensive causing blood loss during birth leads to infarcion
- Presents as inability to breast feed
104
Empty Sella
- Absence of sella due to herniation of arachnoid or brain matter and compression
- Most commonly seen in obese women
- MRI will show no AP in sella
105
Diabetes Mellitus I
- Caused by immune destruction of beta cells (central in islets of langerhans). Ab present and also type 4 hypersensitivity. Will show leukocytic infiltrate
- Minimal genetic concirdance when compared to type 2
- DKA risk
- Insulin dependent
106
Diabete Mellitus 2
- Caused by reduced sensitivity to insulin peripherally. Decrease receptor and downstream signalling
- High genetic concordance 90% in identical twins
- Highly associated with obesity
- NonKetoticHyperosmolar Coma is risk
- Amylin deposits of insulin amyloid will be seen in islets
107
DKA
- Elevations in serum ketones (Beta hydroxybutyrate more than acetone) leading to high anion gap metabolic acidosis
- Often caused by stress which induces cortisol and increased FFA breakdown
- Present with metabolic acidosis, serum hyperkalemia with cellular hypokalemia (transcellular shift to buffer pH)
- Kussmaul respiration, epigastric pain with vommiting and naseua
- Can cause mucor, cardiac arrythmias, cerebral edema, candida infection
- Tx: Glucose and insulin. Also K to replete the intracellular stores
108
NonKetotic Hyperosmolar Coma
- Massive elevations in blood glucose lead to severe polyuria and dehydration causing electrolye imbalances with hyperosmalrity possibly progressing to coma
- Commonly caused by stress which induces release of epi and GH leading to GNG stimulation and glycogenolysis
- Tx: Fluids, Electrolytes, insulin
109
Non enzymatic glycosylation
- Glucose exists in open and closed form, open is highly reactive and can glycosylate basement membrane
- Small vessel leads to hyaline arteriolosclerosis, microalbuniuria progressing to nephrotic syndrome (nodular sclerosing with kimmeslstein wilson nodules), glaucoma, retinopathy
110
Osmotic Damage
- Elevated glucose turned into sorbitol by aldose reductase which cannot leak out of tissue and builds up causing increased pressure.
- Most commonly seen in tissues that can take up glucose independent of insulin
- Lens causes cataracts
- Schwann Cells causes peripheral neuropathy
- Pericytes cause retinal hemorrhage
111
Complications of pregnancy and diabetes
- Human placental lactogen acts simliar to GH and can cause elevations in glucose levels
- Listed complications more associated with DM than Gestational diabetes
- Most common cause of transposition of the great vessels
- Caudal regression syndrome: Sacral agenesis
- PDA, polydactyly, aortic coarcataion, hypospadias
112
Carcinoid
- Neuroendocrine tumor that secretes large amounts of seretonin
- Most common tumor of small bowel and appendix, but will be assymptomatic due to first pass metabolism unless metastasize (most commonly to liver)
- Elevated levels of urinary 5-HIAA (5-HT metabolite)
- Can also be from neuroendocrine tumors in lung
- Causes diahrhrea, flushing, asthma, right sided valvular problems.
- Niacin wasting because of cofactor requirment
- Tx: octreotide
113
Zollinger Ellison
- Gastrin secreting tumor, most commonly of pancreas (MEN-1) but can also be from small bowel
- Causes parietal cell hyperplasia and treatment resistant gastric ulcers that may extend into jejunum
- Tx: Somatostatin, PPI
114
MEN-1
- AD mutation in TSG leads to tumors in the pancreas, pituitary, and parathyroid
- Gastrinoma: ZE
- VIPoma: Diahrrea and hypokalemia
- Insulinoma: hypoglycemia with C peptide
- Glucagonoma: hyperglycemia with painful itchy rash
115
MEN2A
-Mutation in RET oncogene causes Medullary Thyroid, Pheochromocytoma, PTH
116
MEN2B
- Muation in RET oncogene leads to Medullary Thyroid, Phoechromocytoma, and Cutaneous or GI neruotumors
- Also causes marfanoid habitus
