Exam 1-Endocrine Flashcards
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What are the three types of cell signaling?
paracrine, autocrine and endocrine
What are the three general disruptions of the endocrine system?
impaired hormone release/synthesis, abnormal reactions between hormones and target tissue, and abnormal response of target tissue
What can mass lesions cause?
under or overproduction of hormones or be nonfunctional
What are the lobs of the pituitary gland?
anterior lobe(adenohypophysis)-80% and posterior lobe(neurohypophysis)-20% of gland
What three cell types make up the anterior pituitary?
basophils, acidohpils and chromophobes (call can secrete each hormone)
What are the 6 major cell types of the anterior pituitary and what do they secrete?
somatotrophs-GH mammosomatotrophs- GH and prolactin(PRL) lactotrophs- PRL corticotrophs- ACTH, POMC, MSH thyrotrophs- TSH gonadtrophs- LH, FSH
determined by transcription factors
What is produced in the posterior pituitary?
ADH(VPN) and oxytocin
What is involved with hyperpituitarism?
excess trophic hormones, from adenomas, hyperplasia and carcinomas of the anterior pituitary or by from non pituitary tumors or hypothalamic disorders
What is involved with hypopituitarism?
deficiency in trophic hormones from destructive processes like ischemia, surgery or radiation, inflammation and nonfunctional pituitary adenomas
What is involved with local mass effect?
radiologic abnormalities in sella turcica, including expansion, bony erosion and disruption of the diaphragma sella, can compress optic chiasm(bitemporal hemianopisa), increased ICP or hemorrhage into the adenoma, pituitary apoplexy, emergency if acute
What is the most common cause of hyperpituitarism? and other causes?
anterior lobe adenoma-secrete 2 hormones: most common secretions are GH and PRL, but others can be plurihormonal
less common: pituitary carcinoma and hypothalamic disorders
the larger ones can cause mass effect thus causing hypopituitarism through ischemia
What are the demographics for pituitary adenomas?
35-60yo adults, non-functioning adenomas come to light later than functioning due to lack of endocrine response
What is the sizing of pituitary adenomas?
less than 1 cm = microadenoma
1-4cm = macroadenoma
over 4cm = giant adenoma
What genetics abnormalities are associated with pituitary adenomas?
G-protein mutations, GNAS mutation found in 40% of somatatroph adenomas but rarely in corticotroph adenomas, GNAS inhibits GTPase activity thus GDP cannot bind and inhibit the alpha subunit
Which pituitary adenoma is most common?
lactotroph adenoma in 30% of cases with hyperfunctioning pituitary, can have substantial mass affect
What is the morphology of prolactinomas?
chromophobic sparsely granulated (most common) due to inclusions of PIT-1 near the nuclei only, or acidophilic densely granulated (rare) where the cytoplasm is overwhelmed by the inclusions,
these adenomas can undergo calcification and give psamomma bodies throughout the entire mass leaving a “pituitary stone”, even microadenomas can cause hyperprolactinemia, level correlates with size
What is the presentation of lactotroph adenomas? More specifically between M/F?
more readily Dx in women than men due to amenorrhea mostly between 20-40yo, tumor is usually larger in males due to this late finding,
women show amennorhea, galactorrhea, diminshied libido, infertility and amss effect, Men present with mainly mass effect Sx and also decreased sperm count and libido
What can cause hyperprolactinemia without an adenoma?
pregnancy, lactation/nipple stimulation, stress, loss of dopamine-> lactotroph hyperplasia via stroke, trauma or drugs, masses-decrease dopamine release, renal failure- decreased PRL clearance and hypothyroidism-TSH can stimulate PRL
What is the treatment for lactotroph adenomas?
surgery or dopamine agonists- bromocriptine
What is the second most common pituitary adenoma?
somatotroph adenoma, secretes GH
What are the two major findings in somatatroph adenomas?
gigantism in children and acromegaly in adults
What are the morphological findings in somatotroph adenomas?
densely granulated acidophilc cells and sparsely granulated chromophobe cells which have GH inclusions similar to lactotroph adenomas; while there is also a bihormonal mammosomatotroph variant which secrets GH and PRL and typipcally are densely granulated but rare
What is the presentation of gigantism and acromegaly?
gigantism is found when IGF-1 levels are high in children before epiphyseal plates are fused and are typically very tall people, while the findings of both can overlap if the levels stay high after fusion, acrogmegaly shows up as large jaws, hands and noses with coarse facial features, as well as shortened lifespans and CV disease leading to death
How are GH excess pituitary tumors diagnosed?
IGF-1 levels since this is the stable byproduct of GH from the liver, followed by oral glucose tolerance test if elevated which should decrease GH in the blood under normal circumstances
How is the somatotroph tumor treated?
surgery or somatostatin analogs which inhibit GH production, this can casue all Sx to resolve
Which adenoma causes hypercortisolism and why?
caused by corticotroph adenomas secreting excess ACTH thus releasing cortisol
What morphology is seen in corticotroph adenomas?
basophilic densely granulated and chromophobe sparsely granulated tumors, both PAS positive due to POMC the ACTH and beta-endorphin precursor
What is Cushing disease versus the syndrome?
syndrome is from high cortisol levels while the disease is from increased levels of ACTH causing increased cortisol
How is Nelson syndrome caused and what is involved?
large desructive pituitary tumors develop after surgical removal of adrenals to treat Cushing syndrome leads to loss of inhibition of pituitary by corticosteroids and thus increased ACTH or precursor POMC production leading to hyperpigmentation
What is the most common cause of Cushing syndrome?
Iatrogenic due to corticosteroid administration
How are corticotroph adenomas differentiated from ACTH-secreting tumors?
the adenomas maintain some ability to be supressed by high dose corticosteroids(dexamethasone) or elevated response to CRH administration
How can corticotroph adenomas treated?
surgery, bromocriptin or somatostatin analogs, these tumors have some receptors for the above
What is seen in gonadotroph adenomas?
very minimal function and do not cause symptoms therefore are “null cell” or “silent” tumors
How do nonfunctioning adenomas typically present?
mass effect findings
What are thyrotroph adenomas?
very rare and are a cause of hyperthyroidism
What genetic findings are connected to specific pituitary adenomas?
GNAS-somatotroph tumors
USP8- corticotrop tumors(EGFR upregulation)
AIP or FIPA- pituitary adenoma predisposition(PAP)- typically somatotroph adenoms and are familial
Which tumors are well circumscribed?
adenomas, but can erode bone and bleed
Which tumors are poorly cirumscribed?
aggressive adenomas, can invade brain and are more likely with larger adenomas
What are characteristics of pituitary carcinoma?
rare and can metastasize or spread into brain
Define hypopituitarism.
decreased secretion of pituitary hormones as result of hypothalamic or pituitary disease, occurs with 75% loss of gland
List the most common causes of hypopituitarism. (7)
tumors/mass/cysts TBI/hemorrhage surgery/radiation/apoplexy ischemic necrosis/Sheehan syndrome inlammatory disorders genetic defects
What is Sheehan syndrome?
during pergnancy the pituitary gland swells and can get so large that it infarcts, due to lack of blood flow and hemorrhage during birth, and cannot maintain homeostasis any longer, typically occurs at labor
What is Rathke’s cleft cyst?
lined by ciliated cuboidal cells can accumulate fluid causing mass effect on pituitary gland
What is empty sella syndrome?
anything casuing destruction of pituitary gland,
primary is caused by compression with CSF
secondary is caused by infarction of the gland within the sella or with surgical removal
What can be seen in children with hypopituitarism?
pituitary dwarfism
What two groups make up hypothalamic supraselar tumors?
craniopharyngioma and gliomas
What are characteristics and demographics of craniopharyngiomas?
peak in children 5-15yo, with growth retardation, and adults 65yo+, usually with visual disturbances and HA, involved with WNT and B-catenin signaling
Which morpholical findings are in each age range?
kids have adamantinomatous type, while adults have the papillary type, overall arise from Rathke’s pouch, with squamous epithleium, wet keratin and contain calcified cysts
What is the survival of craniopharyngiomas?
less than 5cm is excellent as are the others although larger tumors can cause other issues
What are the major posterior pituitary disorders?
Diabetes inspidus and SIADH
What is seen in DI?
too little ADH, can be central, or not producing enoguh or nephrogenic when the kindey cannot respond to it,
patient has dilute excessive urine, increased serum osmolality, hypernatremia, pulyuria, polydipsia
How do you distinguish central and nephrogenic DI?
give DDAVP, does urin concentration increase? yes-central, no-nephrogenic
What are characteristics of SIADH?
hyponatremia, concentrated urine, low serum osmolality, hypernatriuria, mental status changes, weakness, SZ, cerebral edema but no peripheral
What are causes of SIADH?
SCC of the lung and other CA
TBI/subarachnoid hemorrhage
Drugs-SSRIs
What are the different types of hyperparathyroidism?
primary-caused by end organ dysfunction
secondary caused by another issue somehwere in the body, hypocalcemia chronically
tertiary is continued PTH elevation after prolonged hypocalcemia is corrected
What is the most common cause of primary hyperparathyroidism?
sporadic adenoma(85-95%)
hyperplasia(5-10%)
carcinoma(1%)
What are the demographics or primary hyperparathyroidism?
adults >50yo, 4:1 in women to men
What genetic factors play a role in development of sporadic parathyroid adenomas?
cyclin D1 overexpression linked to PTH gene
MEN1 mutations result in 20-30% of sporadic adenomas
What genetic dispostions are associated with familial parathyroid adenomas?
MEN1 and MEN2 caused y mutation in MEN1 and RET genes respectively
as well as familial hypocalciuric hypercalcemia(AD, loss-of-function in CASR)
What imaging is useful for seeing parathyroid adenomas?
technetium scan, fuse with CT for localization
What is the morphology of parathyroid adenomas?
solitary, benign chief or oxyphil cells, surrounded by rim of normal parathyroid tissue(has adipocytes), soft tan, reddish-brown, other glands are shrunken due to feedback inhibition, not true in hyperplasia
Are sporadic or familial parathyroid adenomas more common?
sporadic but still due to MEN1 gene just not familial MEN1
What are characteristics of parathyroid hyperplasia?
multiple glands, most likely due to MEN syndrome, no sporadic, secondary form is most common, no normal parathyroid tissue at rim, no adipocytes
Why can PTH be monitored in surgery?
due to short T1/2, so a new baseline can be determined, if it doesn’t decrease after surgery think carcinoma
How can parathyroid carcinoma be diagnosed?
metastasis, invasion of adjacent tissues, vascular invasion, PTH doesn’t decrease after surgery
What are Sx of primary hyperparathyroidism?
osteoporosis, osteitis fribosis cystica nephrolithiasis constipation, gallstones depression, lethargy, SZ weakness, fatigue heart valve calcifications
What are characteristics of osteitis fibrosis cytica?
aka von Recklinghausen’s disease of bone
brown tumor, destroys bone with osteoclast resorption, causes small fractures, hemorrhage and reactive tissue, can look like metastasis, usually asymptomatic due to routine lab identification
Most common cause of asymptomatic hypercalcemia?
primary hyperparathyroidism
Most common cause of symptomatic hypercalcemia?
hypercalcemia of malignancy
What causes secondary hyperparathyroidism?
chronic hypocalcemia, leading to compensatory overactivity of the gland
What bone disorder can secondary hyperparathyroidism lead to? and what does it show?
renal osteodystrophy, dissecting osteitis leading to rugger jersey sign
What vascular disease can secondary hyperparathyroidism lead to?
calciphylaxis, extensive calcification and occlusion of vessels with ischemia, patients die from infection
What is the mechanism of hypercalcemia of malignancy?
humoral hypercalcemia of malignancy is caused by PTHrP from squamous cell CA or vitamin-D mediated from lymphomas
local osteolytic hypercalcemia
caused from bone breakdown by osteoclasts and calcium release secondary to breast CA and myeloma
What are the causes of acquired hypoparathyroidism?
iatrogenic- surgery and autoimmune-due to ASP1 and AIRE mutations, presents in childhood with candidiasis and adrenal insufficiency
What are causes of congenital hypoparathyroidism?
DiGeorge syndrome, CASR mutations, familial isolated hypoparathyroidism
What causes DiGeorge syndrome?
failure of 3rd and 4th pharyngeal pouches to develop, parathyroid glands do not develop, 22q11
What causes familial hypocalcemic hypocalciuria?
CASR mutation, overactive calcium sensor
What causes familial isolated hypoparathyroidism?
cannot convert precursos PTH to functional PTH, GCM2 gene mutation, helps parathyroid develop
What are the hallmark findings in hypocalcemia? Other findings?
tetany, determined with chvostek’s sign and trousseau’s sign, others include mental status changes, intracranial manifestations(ICP increase, parkinsonian Sx), ocular disease, CV issues, dental abnormalities
What are characteristics of pseudohypoparathyroidism?
normal or elevated PTH, hypocalcemia and hyperphosphatemia, PTH resistance, GPCR defect, affects TSH, LH/FSH pathways as well
What cells make up the thyroid gland follicles?
cuboidal to low columnar cells
What is another name for TSH and how does it stain?
thyrotropin stains PAS-positive
What occurs when TSH binds thyroid cells?
GPCR activation causing increased cAMP causing production of T4(thyroxine) and less T3(triiodothyroxine) from thyroglobulin
What is the essential action of thyroid on the body?
increase basal metabolic rate (HR, metabolism, glucose usage, growth) also lowers TSH released for negative feedback
What is the simple description of hyperthyroidism?
increased free T3 and T4 in the blood causing hypermetabolic state(also called thyrotoxicosis)
What are the most common causes of thyrotoxicosis?
diffuse hyperplasia(Graves disease) hyperfunctioning multinodular goiter hyperfunctioning thyroid adenoma
What occurs during thyroid storm?
sudden severe onset of thyrotoxic manifestations, including the following:
fever, tachycardia, CHF
diarrhea, jaundice
precipitated by pregnancy/postpartum, hemithyroidectomy, amiodarone
make up the burch wartofsky score
What is the treatment for thyroid storm?
beta blockers, NSAIDs, underlying disease treatment such as: high-dose iodide(Wolff-Chaikoff effect), thionamide, radioiodine ablation, surgery
What is the most common etiology of hyperthyroidism?
Gravs disease
What is the classic triad of Graves disease?
hyperthyroidism with hypertrophy
infiltrative ophthalmopathy
pretibial myxedema
What changes in the thyroid histology with active secretion?
intracytoplasmic droplets appear, containing colloid ready to be released
What causes the orbital changes in Graves disease or hyperthyoidism in general?
increased stimulation of the superior tarsal muscle leading to hypertrophy of it and the EOMs causing the eye to bulge, there is also a build-up up adipose tissue in the orbit and myofibroblast differentiation caused by lymphocyte invasion, fibroblasts have TSH receptors(true orbital ophthalmopathy only occurs in Graves disease)
What happens to the nervous system in hyperthyroidism?
overactivity of the SNS produces tremor, amotional lability, anxiety, insomnia and inability to concentrate
also causes proximal muscle weakness and decreased muscle mass(thyroid myopathy)
What CV effects are seen in hyperthyroidism?
increased CO and contractility requiring increased oxygen, tachycardia, palpitations, cardiomegaly, CHF in older patients with existing disease, as well as reversible LV dysfunction with low output(thyrotoxic cardiomyopathy)
What are the effects of hyperthyroidism on bones?
stimulates bone resorption, reducing trabecular bone volume
What is apathetic hyperthyroidism?
older individuals with multiple comorbidities where the increased thyroid comes to attention via labs because the symptoms are overshadowed by the other diseases
What is pathophysiology behind Graves disease?
autoimmune mediated disease, with 90% showing TSI(Ig), very specific to graves.
What is the underlying morphology in Graves disease?
diffuse hypertophy and hyperplasia of the thyroid follicular epithelial cells, no fibrovascular core like in carcinomas, mostly T cell infiltrates, some B cells and plasma cells, skin can show dermopathy, there are papilla projecting into the colloid space
What is the basic definition of hypothyroidism?
structural or functional derangement that interferes with thyroid production
What is the demographic for hypothyroidism?
women 10x more than men, increases with age, and pre-existing or FMH of autoimmune disease
What is congenital hypothyroidism?
cretinism, depends on the extent the mother was without iodine, typically seen in children due to endemic areas of iodide shortage, presents with severe mental and growth retardation, coarse facial features and umbilical hernias, also caused by genetic alterations
What are characteristics of myxedema?
hypothyroidism in older children and adults, similar to cretinism in children, mental/physical sluggishness(slowing), weight gain, cold intolerance, lower CO, hypercholesterolemia, constipation,
What is the most sensitive screening tool for myxedema?
serum TSH levels, high if primary hypothyroidism, low if secondary
What is the underlying cause of Hashimoto thyroiditis?
autoimmune response to thyroid tissue causing its destruction and gradual failurem specifically against T4 and TPO
What is the most common cause of hypothyroidism in iodine-sufficient areas?
hashimoto thyroiditis
What are characteristics of Hashimoto thyroditis?
diffuse, painless enlarged thyroid, low thyroid levels(except in Hashitoxicosis), starts as insult, hypertrophy occurs and terminates in exhaustion, or low thyroid levels, middle aged females, higher propensity for autoimmune diseases, increased risk for B cell lymphoma in the thyroid
What is the morphology in Hashimoto thyroiditis?
T cell and plasma cell mediated injury, breakdown in Treg cells or polymorphisms in CTLA-4 and PTPNN22, histology shows mononuclear infiltrates with germinal centers and atrophic follicle cells with eosinophilic exhcange(Hurthle cell metaplasia)
What are characteristics of granulomatous thyroiditis?
de Quervain’s thyroiditis, occurs in women 4:1 between 40-50, viral origin, painful(most common cause), typically self limiting even without Tx
What morphology is seen in granulomatous thyroiditis?
granulomata, multinucleated giant cells surrounding colloid pools, stage dependent
What is seen in Riedel thyroiditis?
fibrosis, extends from thyroid to surrounding structures, incredibly adherent to surrounding structures, like cement, IgG4 related, showing multiple plasma cells
What are other IgG4 related disease, besides Reidel thyroiditis?
Mikulicz's syndrome(salivary glands) Autoimmune pancreatitis inflammatory psuedotumor multifocal fibrosclerosis(sclerosing mediatinitis Idiopathic retroperitoneal fibrosis inflammatory aortic aneurysm
What is characteristic of diffuse non-toxic goiter?
no nodularity, diffuse enlargment, endemic or sporadic
What is seen with endemic goiters?
caused by iodine deficiency, goitrogens include: cassava root(thiocyanate) and brassicacae(broccoli)
What is seen in sporadic goiters?
common in females at puberty or as young adults, hereditary defects, diet, immune response
What morphology is seen in diffuse goiters?
hyperplastic phase and colloid involution phase, final stage caused by less of a need for thyroid hormone causing a large colloid gland or colloid goiter, brown, glassy, translucent
What is the clinical observation of diffuse goiters?
euthyroid, normal T3, T4, TSH(normal to high), no tracheal deviation, some mass effect can be seen
How are multinodular goiters formed?
hyperplasia, regression(involution), varied response to stimuli and can be neoplastic adenomas(often mistaken for neoplasms due to size)
What are characteristics of multinodular goiters?
can produce mass effect like diffuse goiters(vena cava syndrome) can become rather large, can become autonomous leading to increased size, large size and involution can lead to hemorrhage
What is the morphology of multinodular goiters?
can become intrathoracic or plunging goiters that dip below the sternum, can have calcification, hemorrhage, cystic changes and fibrosis, histology shows flat colloid rich follicles along with follicular hyperplasia without a dividing capsule
How does radioisotope scanning work?
hot nodules have high iodine uptake and cold have low uptake but each have low risk of malignancy with cold having a slightly higher risk
How are fine needle aspirations used in thyroid nodules?
used to determine cellular constituents to determine malignancy versus benign tumors
What thyroid nodules are benign?
hyperplastic (adenomatoid) nodules
follicular adenomas
What thyroid nodules are malignant?
papillary thyroid carcinoma
follicular/Hurthle cell carcinoma
anaplastic carcinoma
medullary carcinoma
What are characteristics of follicular adenomas?
discrete clonal population of follicular cells the thyroid autonomy, benign but must have capsule(not invasive), so no growth pattern of follicular carcinoma, no nuclear features of follicular carcinoma, Dx made after microscopic examination
What are characteristics of papillary thyroid carcinomas?
make up 85% of malignant thyroid tumors, occur between 25-50yo, asymptomatic with palpable nodule or on US, RET-PTC or BRAF mutation
What is important about thyroid carcinoma staging?
no matter the staging the prognosis is better below the age of 55
What morphological findings are seen in papillary thyroid carcinoma?
papillary architecture and psammoma bodies(calcifications), usually no vascular involvement, Dx can be made based on orphan Annie eye nuclei which are large clear nuclei(also called ground glass)
What is the morphology of the follicular PTC variant?
follicular architecture, with similar nuclear features, less RET-PTC and BRAF mutations, more RAS mutations, vascular invasion
What is the morphology for the tall cell PTC variant?
more aggressive and found in older patients, BRAF and RET-PTC mutation
What is the morphology of the diffeuse sclerosing PTC variant?
kinds and young adults, greater incidence of distant metastasis, shorter period of disease-free survival, mortality rate similar to conventional PTCs due to age possibly, 93% disease-specific survival at 10 years
What are the therapeutic options for PTC?
surgery, radioactive iodine, if no reponse-chemo or RTK inhibitors in progress
What is the morphology of papillary microcarcinoma?
conventional but less than 1cm, typically incidental findings during surgery
What are the characteristics of follicular carcinoma?
5-15% of thyroid carcinomas, more common in women 3:1 and older patients between 40-60yo, frequent in areas with iodine deficiency(25-40% of thyroid carcinoma there)
What morphological features are seen in follicular carcinomas?
invasive if capsule invasion seen and angioinvasion is seen, still considered differentiated thyroid carcinoma, hematogenous metastasis
What are characterstics of anaplastic carcinoma?
5% of thyroid tumors, occur in the elderly, highly aggressive, present with mass effect, on trachea and esophagus, and cause death within 1 year of local invasion
What are the genetic factors involved in PTC?
RET/PTC lead to RTK activity
DRAF lead to MAP kinase signaling
What genetic factors are involved in follicular carcinoma?
PAX8-PPARG but less than 10% of tumors are positive
What genetic factors are involved in anaplastic carcinoma?
TP53 and B-catenin
What do C cells secrete?
calcitonin to help bone absorption of Ca2+
What are characteristics of medullary carcinoma?
neuroendocrine carcinoma from C cells, small round bluecell carcinoma with chromatin, amyloid deposits(apple-green birefringence with congo red stain), c-cell hyperplasia(typical of familial cases)
What are the characterstics and prognosis in familial MTC?
30% of MTCs, best prognosis(100% 15yr survival), multifocal, mean age = 43
What are the characterstics and prognosis in sporadic MTC?
70-80% of all MTCs, unifocal tumor, mean age=50, aggressive(50% LN metastasis at Dx)
What are the 10 year survival rates of MTC depending on location?
thyroid only-90%
cervical LN spread- 70%
distant sites-20%
What genetic mutations is assocaited with MTC?
RET proto-oncogene, typically familial but also sporadic
What are the 6 cell types that make up the endocrine pancreas and their products?
beta-insulin
alpha-glucagon
delta-somatostatin
PP cells-pancreatic polypeptide
delta1-VIP (glycogenolysis and hyperglycemia)
enterochromaffin- serotonin(carcinoid tumors)
What are characteristics of diabetes mellitus?
group of metabolic disorders that have hyperglycemia in common; leading cause of ESRD, adult-onset blindness and non-traumatic lower extremity amputations due to atherosclerosis of arteries, top 10 killer in the US
What is the diagnostic criteria for DM?
fasting plasma glucose >126
random plasma glucose >200(doesnt need repeat)
2hr plasma glucose >200 with OGTT(75mg LD)
HbA1c > 6.5%
How is prediabetes defined?
fasting glucose 100-125
2hr plasma glucose 140-199 with 75mg OGTT
HbA1c 5.7-6.4%
1/4 develop DM in 5 yrs
What is the classification of T1D?
autoimmune disease directed towards beta-cells and insulin deficiency
What is the classification of T2D?
combination of insulin resistance and inadequate response by beta-cells(relative insulin deficiency)
typically obese, increasing in younger ages due to this
What genetic defects can be seen in T2D relating to beta cell function?
MODY1- HNF4A MODY2-GCK MODY3-HNF1A MODY4-PDX1 MODY5-HNF1B MODY6-NEUROD1
neonatal diabetes-KCNJ11(Kir6.2) and ABCC8(SUR1)
MIDD- mito DNA mutations
insulin gene mutations and proninsulin conversion defects
What defects are related to T2D concerning insulin?
Type A deficiency
lipoatrophic diabetes
What exocrine pancreatic defects lead to T2D?
chronic pancreatitis pancreatectomy neoplasia cystic fibrosis hemachromatosis fibrocalculous pancreatopathy
What endocrinopathies are related to T2D?
acromegaly cushing syndrome hyperthyroidism pheochromocytoma glucagonoma
What genetic syndromes are associated with T2D?
Down syndrome
kilnefelter syndrome
turner syndrome
prader-willi syndrome
Waht infections can lead to T2D?
CMV
coxsackie B virus
congenital rubella
What are the important factors that T1D has and are not seen in T2D?
insulinitis, autoimmune, younger patients, normal or low weight, circulating Ab, MHC II linkage,
What 3 effects regulate glucose homeostasis?
glucose production in liver, glucose uptake and utilization in peripheral tissue and actions of insulin and other regulatory hormones on metabolism
What can be measured to determine if insulin is being produced in the body?
C-peptide
What make up the incretins and what do they do?
GIP and GLP-1, causes the quick regulation of blood glucose by being released when food is ingested instead of waiting for levels to rise
What diabetic drugs take advantage of incretin effects?
GLP-1 and GIP receptor agonists are used to increase these effects as well as DDP inhibitors which allow the incretins to stay in the blood longer
What drug is a great choice for treating hypercalcemia?
bisphosphonate, which inhibits actions of osetoclasts, not effective with hypersecretion of Vit D
What are the effects of insulin?
increase glucose uptake(GLUT4), decreased glucose production in cells, increase potassium movement into cells, increase fat production, increase glucose storage as glycogen
What genetic defects play a role in T1D?
HLA gene on chromosome 6p21, causing up to 50% of T1D
DR3/DR4 haplotypes
non-HLA genes such as VNTRs, CTLA4 and PTPN22(autoimmune thyroiditis), AIRE(type 1, APS)
What environmental factors lead to T1D?
possibly viral infections via molecular mimicry
What is the fundamental immune abnormality in T1D?
failure of T cell self-tolerance for islet Ags, as well as insulin Ags, but it is unclear if this is the cause or byproduct of injury
What environmental factors play a role in T2D?
obesity
What 2 metabolic defects play a role in T2D?
insulin resistance and beta-cell dysfunction
the insulin resistance causes hyperfunction of beta cells which then get overworked and are no longer able to compensate
What does insulin resistance result in?
cannot inhibit glucose production by liver, cannot take in glucose after meals, cannot inhibit HSL thus FFAs are high in blood
How does exercise improve insulin sensitivity?
brings GLUT4 to the cell surface1
What body habitus factors increase risk for T2D?
obesity and central distribution
How do FFAs affect the body in T2D?
inverse relationship with insulin levels, increase toxic intermediates in blood(DAG) which decrease insulin levels
What affect to adipokines have on T2D?
those that are increased promote hyperglycemia, and those that are reduced result in insulin resistance and allow for increased glucose levels(adiponectin and leptin)
What inflammatory affects potentiate T2D?
FFAs cause macrophages and B cells to create inflammasomes releasing IL-1 which promote insulin resistance
What are some mechanisms that promote beta cell dysfunction in T2D?
FFAs, chronic hyperglycemia, abnormal incretin effect, amyloid depsotion in islets, genetics
What is the most common cause of MODY and how does it present?
glucokinase deficiency, increased insulin levels, no autoantibodies, nonketotic, young patients but looks like T2D
What chracteristics do insulin receptor mutations show in patients?
rare, acanthosis nigricans, PCOS, increased androgen levels, lipoatrophic diabetes(loss of adipocytes in subcutaneous fat),
How can diabetes occur in pregnancy?
mother had diabetes before becoming pregnant or was euglycemic and began to have hyperglycemia after pregnancy
How does diabetes affect pregnancy?
it is a diabetogenic state promoting insulin resistance, no matter when the diabetes develops the baby has a risk of being large for gestational age(macrosomia) and developing obesity or DM later in life, but if the mother has pregestational diabetes there is increased risk for stillbirth and congenital malformations, the baby is at risk for hypoglycemia and SZ as well, while the mother may need to have a C-section
How can gestational diabetes be diagnosed?
prenatal visit with fasting glucose >126, random glucose >200 or HbA1c>6.5%
between 24 to 48 weeks with fasting glucose >92, OGTT >180 @ 1hr post, or >153 @ 2hr post
What is the classic clinical triad of T1D?
polyuria, polydipsia, polyphagia and when severe DKA
What are characteristics of DKA?
T1D mostly, typically caused by non-compliance, but also infection and trauma, associated with epinephrine release which inhibits insulin effects and stimulates glucagon, causes osmotic diuresis and dehydration, ketone bodies are produced from FFA breakdown leading to ketonuria and ketonemia, Kussmaul breathing
What is the classic triad of DKA?
hyperglycemia, ketonemia, metabolic acidosis
How can DKA be treated?
insulin, hydration, potassium, and underlying causes treatment
What complication is more typical in T2D?
hyperosmolar hyperosmotic syndrome(HHS)
What should be tested for in DKA?
urine ketones, beta-hydroxybutyrate and acetoacetic acid
What occurs during HHS?
severe dehydration due to osmotic diuresis, due to lack of water intake from a debilitating disease, hyperglycemia is typically higher then DKA (600-1200mg/), no ketones
What is the most common acute complication for both T1D and T2D?
acute hypoglycemia from missing meals or too much insulin or exertion, Sx include dizziness, confusion, sweating, palpitations and tachycardia, LOC can occur along with permanent CNS damage if prolonged
What are the chronic complications of diabetes?
micro/macrovascular disease(i.e., atherosclerosis, retinopathy, nephropathy and neuropathy)
What is the main cause for chronic complications in diabetes?
persistent hyperglycemia measure by HbA1c, or glycated hemoglobin, should be kept under 7% in diabetics, also can be caused by insulin resistance and obesity
What are the 4 proposed mechanisms for deleterious effects of diabetes?
formation of advanced glycation end products, protein kinase C activation, oxidative stress and polyol pathways, and hexosamine/F6Pd
How do glycation end products affect patients?
AGE binds its receptor(RAGE) and form cytokines and GF which thicken BM and activate VEGF, ROS generation, procoagulant activity, smooth muscle proliferation and ECM synthesis-vascular abnormalities
How does activation of PKC affect patients?
DAG produced from PKC and FFAs cause increase PKC activation leading to increased VEGF, TGF-B and PAI-1(procoagulant)-vascular abnormalities
How does oxidative stress and prolyol pathway affect patients?
NADPH is decreased and GSH cannot regenerate so sorbitol is not broken down by aldose reductase leading to buildup in the eye and cataracts as well as decreased resistance to oxidative stress
How do hexosamine and F6P affect diabetic patients?
hexosamine creates F6P which is a substrate for glycosylation leading to increased proteoglycans and abnormal TGF-B and PAI-1 production
What pancreatic morphology is seen in diabetic patients?
decreased number and size of islets(T1D), leukocytic infiltrates(T1D), amyloid deposition(T2D), an increase in number and size of islets in babies from mothers with hyperglycemia
What macrovascular morphology is seen in patients with diabetes?
endothelial dysfunction, accelerated atherosclerosis, hyaline ateriosclerosis, gangrene in LE
What is the most common cause of death in diabetics?
MI caused by coronary atherosclerosis
What microvascular morphology is seen in diabetics?
diffuse thickening of BM, leaky capillaries, these underlie neuropathy, nephropathy and retinopathy
What morphology is seen in diabetic nephropathy?
glomerular lesions, renal vascular lesions(arteriosclerosis), and pyleonephritis(necrotixing papillitis), thickening of GBM, diffsue increase in mesangial matrix, intercapillary glomerulosclerosis(Kimmelstein-Wilson disease)(PAS-positive deposits),
What ocular morphology is seen in diabetics?
opacification of the lends(cataracts), glaucoma, most effects are seen in the retina
What diseases are diabetics prone to?
skin infections, TB, pneumonia, pyelonephritis
What is seen clinically with diabetic macrovascular disease?
MI x2, stroke, renal vascular insufficiency, CVA, gangrene 100x, HTN in 75%, dyslipidemia, elevated PAI-1(procoagulant)
What is seen clinically in diabetic nephropathy?
30-40% of diabetics get nephropathy, leading cause of ESRD, screened with albumin:creatinine ratio(GOLD STANDARD), starts with microalbuminuria(<30mg/day) but can progress to macroalbuminuria(>300mg/day), then ESRD in 75% of T1D and 20% of T2D
What causes diabetic retinopathy?
VEGF elaboration
What is the most frequent pattern of neuropathy in diabetics?
distal symmetric neuropathy affecting motor and sensory function, sock and glove pattern, can affect autonomics(bowel and bladder) or create wrist and footdrop due to nerve injury
Are PanNETs or exocrine pancreatic tumors more common?
exocrine, PanNETs are only 2% of pacnreatic tumors
What are the major genetic mutations involved with PanNETs?
MEN1, PTEN & TSC2(mTOR), ATRX, DAXX
What are the characteristics of insulinomas?
beta-cell tumors, most common PanNET, can cause significant hypoglycemia, small solitary tumor and least likely to metastasize, C-peptide levels can Dx, amyloid is a common finding, the majority are not clinically significant
What is the triad of ZE syndrome?
pancreatic islet tumor, gastric acid hypersecretion, peptic ulceration
What are the characteristics of gastrinomas?
ulcers refractory to conventional therapy, can be in the duodenum and pancreatic ST as well as islets, diarrhea, treat with proton pump inhibitors and surgery
What are charactersitics of delta cell tumors?
somatostatinomas, related to diabetes, gallstones, steatorrhea, due to its inhibitory nature, reduces insulin, GB motility, and exocrine secretions
What are characteristics of alpha cell tumors?
glucagonomas, cause mild diabetes, dermatitis(necrolytic migratory erythema), depression and DVTs as well as anemia, occurs around and after menopause
What are characteristics of delta1 cell tumors?
VIPoma, cause watery diarrhea, hypokalemia, and achlorydia, similar to neural crest tumors and pheochromocytoma
What are the layers of the adrenal glands?
GFR->salt, sweet, sex and the medulla with catecholamines
What is Cushing syndrome?
hypercortisolism for any reason
What is Cushing disease?
Hypercortisolism due to excess ACTH from the pituitary gland
What is the most common cause of Cushing syndrome?
iatrogenic causes, from glucocorticoid administration
What causes most cases of endogenous hypercortisolism?
corticotroph adenomas cause 70% due to increased ACTH(Cushing disease), although corticotroph hyperplasia can occur due to increased CRH from hypothalamus tumor
What percentage of ectopic ACTH causes dependent Cushing syndrome?
10%, usually due to SCC of lung, this can also secrete CRH, more common in men from 40-59
What is the most common cause of ACTH-indpendent Cushing syndrome?
primary adrenal neoplasms, adenomas(10%) and carcinomas(5%)
What characteristics are seen in primary adrenal hyperplasia?
ACTH dependent, unless specifically cortical which is independent, as well as macronodular hyperplasia
What are the genetic mutations associated hypercortisolism?
McCune-Albright-GNAS
primary pigmented nodular adrenal disease- PDE11 and PRKARIA
macronodular hyperplasia- ectpoic hormone receptors expression
What morphology is seen in Cushing syndrome?
pituitray shows changes no matter the cause, most commonly Crooke hyaline changes due to excexx ACTH on the corticotroph cells making them appear pale, lack of ACTH causes atrophy of the adrenals, diffuse hyperplasia is seen in ACTH-dependent Cushing syndrome, macronodular hyperplasia shows lipid deposits in the adrenals, micronodular hyperplasia shows pigmented modules with atrophic areas
What are patient features with Cushing Syndrome?
obesity(centripital), moon facies, deceased libido, abdominal striae, buffalo hump, secondary diabetes due to increased cortisol, osteoporosis
What is the lab diagnosis of Cushing syndrome based on?
increased 24hr urine free-cortisol elevation, loss of diurnal pattern of cortisol secretion
What forms of Cushing can be improved with dexamethasone?
pituitary adenomas can be inhibited by high dose dexamethasone, no other doses are effective for other tumors
What is seen with Conn’s syndrome?
primary hyperaldosteronism, most common cause is idiopathic(possibly potassium channel mutation, KCNJ5), more common in women if aldosteroe secreting adenoma(second most common)
What morphology is present with primary hyperaldosteronism?
adenomas are birght yellow in women in 30s and 40s, may contain spironolactone bodies only if used for treatment, increased ischemic heart disease, BIH can have wedge shaped hyperplasia in both glands
What is seen clinically in primary hyperaldoseronism?
HTN that is refractory and severe <160/100 and at a young age, adrenal mass, hypokalemia and hypomagnesemia
What is seen in secondary hyperaldosteronsim?
activation of RAAS, diuretic use, decreased renal perfusion, hypovolemia, pregnancy, renin-secreting tumors
How is primary hyperaldosteronism diagnosed?
elevated aldosterons levels and an ACTH suppression test
What are the charcteristics of adrenogenital syndromes?
virilization, pituitary cause increase ACTH and thus androgens as well, adrenal cause is from adenoma or carcinoma, congenital adrenal hyperplasia is another cause
What types of congenital adrenal hyperplasia can occur?
salt wasting syndrome, simple virilizing without salt wasting, non classic/late-onset adrenal virilism, all are AR
What occurs in classic salt wasting syndrome?
complete lack of 21-hydroxylase enzyme, therefore no aldosterone or cortisol is made and everything shifts toward androgen production, no hypothalamic/pituitary feedback from cortisol, hyponatremia, hypotension, virilization in females, long term can cause adrenomedullary dysplasia
What occurs in simple virilizing syndrome?
partial lack of 21-hydroxylase enzyme, so some corticosteroids and mineralcorticoids are available, but cannot inhibit ACTH still, virilization is seen
What occurs in nonclassic late onset adrenal virilism?
partial lack of 21-hydroxylase, most common form of CAH, precocious puberty, acne and hirsutism
How can CAH be diagnosed?
ACTH levels, glucocorticoids and mineralcorticoids and androgens but most specific is 17-hydroxyprogesterone and ACTH stimulation test
What is the treatment for CAH?
glucocorticoids-inhibit ACTH and replinishes cortisol, mineralcorticoids as necessary
What are the different type of adrenocortical insufficiency?
primary acute, primary chronic(due to lack of adrenal response to stimulation) and secondary(due to lack of stimulation to adrenals)
What is seen in primary acute adrenocortical insufficiency?
adrenal crisis, can be seen due to stress or rapid withdrawal of steroids, as well as adrenal hemorrhage due to prolonged labor in newborns, anticoagulation, post-surgical with DIC, infarction of adrenals and finally with bacterial infection(N. meningititis or H. influenzae) also called Waterhouse-Friderichsen syndrome
What are the findings in WAterhouse-Friderichsen syndrome?
overwhelming bacterial infection, by highly virulent bacteria, N. meningititis, H. influenzae, P. aeruginosa, staph, pneumococci, causes rapid hypotension and shock, DIC with widespread purpura, bilateral adrenocortical insufficiency assocaited with adrenal hemorrhage, most common in children, adrenals are converted to sacs of clotted blood, starting in medulla and moves into cortex, death follows within hours to days
What disorders can cause loss of adrenal cortical cells?
congenital adrenal hypoplasia, adrenoleukodystrophy, autoimmune adrenal insufficency, APS1, APS2, infection, acute hemorrhage, amyloidsosis, sacroidosis, hemochromatosis, carcinoma
What are the signs of acute adrenal insufficiency?
hypotension, abd pain, fever, N/V, hyponatremia, hypoglycemia, hyperkalemia, malaise
What are characteristics of of chronic adrenocortical insufficiency?
addison disease, long duration of malaise of fatigue, anorexia and weight loss, joint pain, hyperpigmentation of skin
What are the four most common causes of chronic adrenocortical insufficiency?
autoimmune adrenalitis-#1 in USA, TB-#1 in underdeveloped countries, AIDS, metastatic cancer
What are the clinical findings of autoimmune adrenalitis?
occurs in 60-70% of chronic adrenocortical insufficiency, APS1 and APS2
What are the characteristics of APS1?
APECED, autoimmune polyendocrinopathy, candidiasis, and ectodermal dystrophy(IL-17 & IL-22), adrenalitis, parathyroiditis, hypogonadism, pernicious anemia, mutation in AIRE gene
What are characteristics of APS2?
adrenalitis, thyroiditis, and T1D
What is seen in ectodermal dystrophy?
enamel, skin and nail anomalies
Why is adrenal metastasis a cause of adrenal insufficiency?
the adrenals are a major site of metastasis and the tissue can be destroyed by cases like this, typically breast and lung carcinomas
What causes the hyperpigmentation in Addison disease?
POMC, the precursor of ACTH and MSH, not the cause in primary pituitary tumors of hypothalamic disease
What are the characteristics of secondary adrenal insufficiency?
disorder of the hypothalamus and pituitary, i.e., CA, infection, infarction, or irradiation, that decreases ACTH which is similar to Addison disease, secondary shows no signs of hyperpigmentation due to lack of ACTH stimulation therefore low POMC and MSH, decreased androgen and cortisol but normal aldosterone due to RAAS
What is different about adrenal adenomas and carcinomas?
carcinomas cause mass effect(due to large size) and virilization, adenomas are more associated with hyperadenalism and Cushing syndrome
What morphology is seen in adrenal carcinomas?
giant cells and dark markings
What cells comprise the adrenal medulla?
chromaffin cells(neuroendocine) and sustentacular cells
What other areas make up the paraganglion system?
bracnhiomeric, intravagal, aorticosympathetic, typically located near major arteries and cranial nerves(carotid bodies)
What are characteristics of pheochromocytoma?
profound hypertension from catecholamine secreation, 10% rule, extra adrenal, nilateral, kids, malignant(metastasis), not assocaited with HTN, 25% are familial, acute complications are related to catecholamines, chronic leads to cardiomyopathy, RET and NF1
What is the classic triad of pheochromocytoma?
HA, palpitations, and diaphoresis
How is pheochromocytoma diagnosed?
plasma and urine metanephrines
What are adrenal incidentalomas?
masses in asymptomatic individuals, CT findings, can be functional but usually not, r/o hypercortisolism and pheochromocytoma
What is an adrenal myelipoma?
composed of fat and bone marrow, varying sizes, can be hemorrhagic
What are charactersitics of MEN syndromes?
younger age, multiple endocrine organs, asymptomatic hyperplasia, aggressive and recurrent
What are charactersitics of MEN1?
Wermer syndrome, parathyroid hyperplasia, pancreatic neuroendocrine tumor and pituitary adenoma, gastrinoma can be in the duodenum also, MEN1 gene mutation(menin) LOF
What are charactersitics of MEN2A?
pheochromocytoma, medullary thyroid carcinoma, and parathyroid hyperplasia, RET oncogene GOF
What are charactersitics of MEN2B?
medullary thyroid carcinoma, pheochromocytoma, mucosal neuromas, marfanoid
What other genetic disorder causes medullary thyroid carcinoma?
familial MTC, RET mutation
What are chracteristics of pineal gland tumors?
photoreceptor tissue, melatonin secretion, germ cell tumors, pineocytomas, and pineoblastoma
