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166 Cards in this Set
- Front
- Back
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what are the other names for type I diabetes?
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- insulin-dependent diabetes mellitus (IDDM)
- juvenile diabetes mellitus - ketosis prone diabetes mellitus |
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epidemiology of T1DM
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- begins early in life (<30)
- due to failure of insulin synthesis by B-cells - cause may be a genetic predisposition complicated by autoimmune inflammation of islets (triggered by virus or environmental factors) |
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what do you call the autoimmune inflammation of islet cells?
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insulitis
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what are the genetic markers that increase risk for T1DM?
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- point mutations in the HLA-DQ gene
- HLA-DR3 and HLA-DR4 -> higher incidence |
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what are the symptoms of T1DM?
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- carbohydrate intolerance -> hyperglycemia.
- leads to polyuria, polydipsia, weight loss despite increased apetite - ketoacidosis - coma - death |
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what causes ketoacidosis?
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- increased catabolism of fat, with the production of ketone bodies (primarily b-hydroxybutyric acid and acetoacetic acid, acetone).
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when do you see ketoacidosis?
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diabetes
starvation |
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what ketone bodies do you see during ketoacidosis?
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- b-hydroxybutyric acid (mainly)
- acetoacetic acid (mainly) - acetone (small amounts) |
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what are other names for T2DM?
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- non-insulin dependent DM
- adult onset DM - ketosis resistant DM |
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what is the epidemiology of T2DM?
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- begins after middle age
- increased insulin resistance from decreased cell membrane insulin receptors or postreceptor dysfunction - may also be associated with impaired processing of proinsulin to insulin - or, decreased sensing of glucose by b-cells - or, impaired function of intracellular carrier proteins |
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what are the symptoms of T2DM?
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- plasma insulin is normal and often increased
- managed by diet and oral antidiabetic agents -> usually don't need insulin therapy - ketoacidosis is unusual, but may occur (precipitated by stress: infection, surgery) - associated with obesity |
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Maturity onset diabetes mellitus of the young (MODY)
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- autosomla dominant
- mild hyperglycemia and hyposecretion of insulin - no loss of b-cells! - caused by diverse group of single gene defects |
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secondary diabetes mellitus
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- secondary to pancreatic and endocrine disorders , and during pregnancy
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secondary DM from pancreatic disease
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- hereditary hemochromatosis (bronze diabetes)
- pancreatitis |
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hereditary hemochromatosis (bronze diabetes)
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- excess iron absorption and parenchymal deposition of hemosiderin
- reactive fibrosis in pancreas, liver, and heart |
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secondary DM due to Carcinoma of the pancrease
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- DM may be the presenting sign
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secondary DM due to non-pancreatic endocrine diseases
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1. cushing's syndrome
2. acromegaly 3. glucagon hypersecretion 4. other endocrine disorders |
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Cushing's syndrome
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- increased cortisol secretion
- produces hyperglycemia from increased gluconeogenesis nand impaired peripheral utilization of glucose |
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difference between cushing's syndrome and cushing's disease
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- Both diseases are characterized by elevated levels of cortisol, but the cause of elevated cortisol differs between the diseases. - Cushing's disease specifically refers to a tumor in the pituitary gland that stimulates excessive release of cortisol from the adrenal gland by releasing large amounts of ACTH.
- Cushing's syndrome can come from drugs |
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acromegaly
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- produces hyperglycemia as a result of increased gluconeogenesis and impaired peripheral utilization of glucose
- may be caused by pituitary adenoma secreting high levels of GH |
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glucagon hypersecretion
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- promotes glycogenolysis
- caused by islet alpha cell tumor (glucagonoma) |
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what is glucagonoma?
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islet alpha cell tumor
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which other endocrine disorders may be associated with hyperglycemia?
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- pheochromocytoma
- hyperthyroidism |
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secondary DM due to pregnancy
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- gestational DM- is transient
- however, overy nongestational DM may sometimes develop later - associated with increased fetal birth weight - increased fetal mortality (from RDS - hyaline membrane disease) |
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hyaline membrane disease
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- developmental insufficiency of surfactant production and structural immaturity in the lungs. It can also result from a genetic problem with the production of surfactant associated proteins. RDS affects about 1% of newborn infants and is the leading cause of death in preterm infants
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what happens when a mother has hyperglycemia?
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- infant may be born with hyperplasia of the pancreatic islets and hypoglycemia
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anatomic changes in pancreatic islets during T1DM
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- islets are small
- fewer b-cells (may be absent) * insulitis marked by lymphocytic infiltration |
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anatomic changes in pancreatic islets during T2DM
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- focal islet fibrosis and hyalinization (deposits of amylin)
- amylin (aka IAPP) is characteristic of T2DM -> interferes with teh conversion of proinsulin to insulin, or with sensing of insulin by b-cells |
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amylin
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- Amylin, or Islet Amyloid Polypeptide (IAPP), is a 37-residue peptide hormone secreted by pancreatic β-cells at the same time as insulin (in a roughly 100:1 ratio).
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anatomic changes in kidney during DM
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- increased thickness of glomerular BM
- diffuse diabetic glomerulosclerosis, nodular diabetic glomerulosclerosis (kimmelstiel-Wilson disease), arteriolar lesions, exudative lesions (firbin cap/capsular drop) - armanni-ebstein lesion- rare - pyelonephritis |
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what is the earliest and most common renal manifestation in DM?
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- increased thickening of the glomerular BM
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Armanni-Ebstein lesion
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- seen in DM
- tubular deposition of glycogen in the kidney - uncommon result of prolonged untreated hyperglycemia |
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pyelonephritis
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- frequent complication of DM
- may be compoudned by renal papillary necrosis |
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anatomic changes in the cardivascular system in DM
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- atherosclerosis -> clincial complications from atheroscleoris appears earlier; incidence in women is increased
- MI and peripheral vascular insufficinecy are common - capillary basement membrane thickening- seen in multiple organs |
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what happens when you get peripheral vascular insufficency?
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gangrene
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what is capillary basement membrane thickening due to?
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- nonenzymatic glycosylation of membrane protein
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anatomic changes in the eye in DM
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- cataracts
- retinopathy (retinal exudates, edema, hemorrhages, and microaneurysms of small vessels) -> blindness |
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anatomic changes in the Nervous system in DM
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- peripheral neuropathy
- changes in the brain and spinal cord |
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anatomic changes in the liver in DM
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- fatty changes in the liver
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anatomic changes in the skin in DM
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- xanthomas
- furuncles and abscesses b/c of increased infection - frequent fungal infections (esp with candida) |
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what are xanthomas?
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- collectison of lipid laden macrophages in the dermis
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what is a furuncle?
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- infection of a hair follicle
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list the types of ant. pit. hyperfunction disorders
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- prolactinoma wih hyperprolactinemia
- somatotropic adenoma with hypersecretion of GH corticotropic adenoma and hypersecretion of ACTH |
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prolactinoma with hyperprolactinemia
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- most common pit tumor (30% of pit tumors)
- chromophobic staining - amenorrhea and galactorrhea - caused by hypothalamic lesions or by medications that interfere wtih dopamine secretion - also associated with estrogen therapy |
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define: galactorrhea
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- inappropriate milk secretion
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name the drugs that interfere with dopamine (prolactin inhibitory factor: PIF) secretion
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- methyldopa
- reserpine |
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somatotropic adenoma with hypersecretion of GH
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- second most common pit tumor
- acidophilic staining - causes secondary hyperproduction of somatomedins by the liver -> GH and somatomedins (and IGF-I, somatomedin C) mediate end organ effects - gigantism/acromegaly |
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define: somatomedin
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A chemical produced by the liver and other tissues in response to human growth hormone (hGH). It plays a role in helping hGH cause changes in cells that lead to growth.
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when do you get gigantism?
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- adenoma develops before epiphyseal closure
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when do you get acromegaly?
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- adenoma develops after epiphyseal closure -> overgrowth of jaws, face, hands, feet
- enlargement of viscera - hyperglycemia - osteoporosis - hypertension |
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corticotropic adenoma and hypersecretion of ACTH
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- results from increased production of adrenal cortical hormones (hypercorticism)
- aka Cushing's syndrome - (Cushing's disease: pit ACTH hypersecretion) |
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Cushing disease
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- hypercorticism due to corticotropic adenoma of the pituitary- most often basophilic adenoma
- also hypercorticism associated with multiple pituitary adenomas (basophilic microadenomas) |
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Cushing syndrome
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- hypercorticism regardless of cause
- most often of pituitary origin (less often adrenal origin) - can be caused by ectopic ACTH production by various tumors (esp small cell carcinoma of lung) |
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which tumor secretes a lot of ACTH?
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- small cell carcinoma of lung
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Classic staining of tumor cells:
- Chromophobic - acidophilic - basophilic |
- prolactinoma
- somatotropic adenoma - corticotropic adenoma or multiple corticotropic microadenomas |
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list the types of anterior pituitary hypofunction lesions
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1. Pituitary cachexia (Simmonds disease)
2. Selective deficiency of one or more pituitary hormones |
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Pituitary cachexia (Simmonds disease)
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- generalized panhypopituitarism
- marked wasting - can develop from any process that destroys the pituitary: pituitary tumors, postpartum pituitary necrosis |
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postpartum pituitary necrosis (Sheehan syndrome)
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- ischeic nbecrosis of the pit glnad
- associated with shock and hemorrhage during childbirth - clinical presentation: loss of gonadotropins, then subsequent loss of TSH and ACTH |
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selective deficiency of one or more pituitary homrons
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1. deficiency of GH
2. deficiency of gonadotropins 3. deficiency of TSH 4. deficiency of ACTH |
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deficiency of GH
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- in children -> growth retardation (pituitary dwarfism)
- adults-> increased insulin sensitivity with hypoglycemia, decreased muscle strength, anemia |
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deficiency of gonadotropins
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- in preadolescent children -> retarded sexual maturation
- in adults-> loss of libido, impoence, loss of muscle, decreased facial hair in med, amenorrhea and vaginal atrophy in women |
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deficiency of TSH
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- results in secondary hypothyroidism
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deficiency of ACTH
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- secondary adrenal failure
- does not cause hyperpigmentation of skin (unlike Addison disease: primary adrenal failure, where ACTH is high) |
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list the problems associated with the posterior pituitary
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1. SIADH
2. deficiency of ADH |
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which hormones are secreted by the post pit?
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- hormones are made in the hypothalamus, and trasnported via axons to the posterior pituitary
1. oxytocin 2. ADH |
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SIADH
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- most commonly caused by ectopic ADH production by tumors (small cell of lung)
- results in retention of water, reduced serum osmolality, and inability to dilute the urine |
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which tumor produces excessive ADH?
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- small cell carcinoma of the lung
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Deficiency of ADH
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- results in diabetes insipidus
- caused b tumors, trauma, inflammatory processes, lipid storage disorders |
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what are the two nonfunctioning pituitary tumors?
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1. nonsecreting pituitary adenoma
2. craniopharyngioma |
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nonsecreting pituitary adenoma
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- chromophibic
- dysfunction from local pressure - tumors are clinically variable presentation: hypopituitarism, headache, bilateral hemianopsia (pressure on optic chiasm), and palsies |
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what causes bilateral hemianopsia?
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- pressure on the optic chiasm
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craniopharyngioma (adamantinoma)
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- benign childhood tumor derived from remnants of the Rathke pouch
- similar to ameloblastoma of jaw - nest and cords of squamous or columnar cells in loose stroma; looks like embryonic tooth bud enamel - often cystic- the lining epithelium of flat or columnar cells expands into papillary projections - can see on radiograph b/c of tumor calcification |
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empty sella sydnrome
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- condition that destroy all or parts of the pituitary
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Nelson syndrome
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- large pituitary adenomas following bilaterial adrenalectomay
- loss of feedback inhibition on growth of preexisting pituitary microadenomas |
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what are serum T3 and T4 bound to?
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- thyroid-binding glubulin (TBG)
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what are the two congenital abnormalities of the thyroid?
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1. thyroglossal duct cyst
2. ectopic thyroid tissue |
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thyroglossal duct cyst
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- most common thyroid anomaly
- remnant of the thyroglossal duct - does not lead to alderations of thyroid function |
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ectopic thyroid tissue
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- can be found anywhere along thecourse of the thyroglossal duct
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what causes goiters?
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- physiologic enlargement
- iodine deficiency - hashimoto thyroiditis - goitrogens - dyshormonogenesis |
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when do you see physiologic enlargement of the thyroid (goiter)?
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- puberty
- pregnancy |
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what is Hashimoto's thyroiditis?
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antibodies attack the Na+/I- symporter which transports iodine into the follicular cells of the thyroid where it is used for thyroid hormone synthesis
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what are goitrogens?
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- foods or drugs that suppress synthesis of thyroid hormones
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what is dyshormonogenesis
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- failure of TH synthesis
- can be caused by enzyme deficiencies |
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what is a simple goiter?
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- nontoxic goiter
- no TH hormone dysfunction |
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what is a toxic goiter?
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- goiter assocaited wtih hyperthyroidism
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what is an endemic goiter
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- goiter found in iodine-deficiency geographic areas
- sporadic goiter: goiter caused by iodine def in non-iodine defi areas |
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what is a nodular goiter?
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- irregular enlargemetn of the thyroid, resulting in nodule formation
- nodular colloid goiter: late stage of a simple goiter - most nodules are hypoplastic and do not take up radioactive iodine (cold) - occassionally, nodules are hot |
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what laboratory abnormalities do you see in hypothyroidism?
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- decreased serum free T4, increased serum TSH
- increased serum cholesterol - decreased T3 resin uptake - decreased Total T4 |
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describe the T3 resin uptake test (aka thyroid hormone-binding ratio: THBR)
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- decreased in hypothyroidism
- inversely proportional to the number of unbound TH binding sites on TBG - measured by competitive uptake of radioactive T3 by resin- which competes for unbound sites on TBG |
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how does hypothyroidism manifest in children and adults?
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- children: cretinism
- adults: myxedema |
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myxedema
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- more common in women than in men
- caused by: - hyperthyroidism surger, irradiation, or drugs - Hashimoto thyroditis - primary idiopathic myxedema- unknown cause (possibly TSH receptor blocking autoantibodies) - iodine deficiency |
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what are the clinical sydnromes of myxedema
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- insidious onset
- cold intolerance - low BMR -> weight gain - lowered voice - mental and physical slowness - menorrhagia - constipation |
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what are the physical findings in a patient with myxedema?
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- puffiness of face, eyelids, and hands
- dry skin - hair loss, coarse and brittle hair, scant axillary and pubic hair, thinning of eyebrows - increased relaxation phase of deep tendon reflexes |
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what causes cretinism?
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- iodine deficiency
- iodine synthesis enzyme deficiency - maldevelopment of thyroid gland - failure of fetal thyroid to descend from the base of the tongue - trasplancental transfer of antithyroid antiboides from mother with autoimmune thyroid disease |
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what are the characteristics of cretinism?
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- severe mental retardation
- growth retardation - stunted bone growth, dwarfism - macroglossia - protuberant abdomen |
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what are the clinical features of hyperthyroidism (thyrotoxicosis)?
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- greatly increased free T4
- restlessness, irritabiliyt, fatigability - tremor - heat intolerance, sweating - tachycardia - msucle wasting, weight loss - fine hair - diarrhea, amenorrhea/ oligomenorrhea |
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what do you see regarding T4 and TSH in hyperthyroidism?
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- greatly increased free T4
- decreased TSH - Total T4 and T3 resin uptake are increased |
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Graves disease- general
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- hyperthyrodism caused by diffuse toxic goiter
- more often in women than in men - HLA-DR3 and HLA-B8 - exophthalmos |
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what are the HLA subtypes associated with Graves disease?
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- HLA-DR3
- HLA-B8 |
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what is the mechanism behind Graves Disease?
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- thyroid stimulating immunoglobulin (TSI) is an IgG antibody
- reacts with TSH receptors -> stimulates TH production - thyroid growth immunoglobulin (TGI) can also stimulate glandular hyperplasia and enlargement |
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what are other causes of hyperthyroidism?
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- Plummer disease
- pititary hyperfucntion - struma ovarii - exogenous administration of TH |
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Plummer disease
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- combination fo hyperthyroidism, nodular goiter, and absence of exophthalmos
- hot nodules can be adenomas or non-neoplastic areas of nodular hyperplasia |
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Pituitary hyperfunction
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- can cause excess prodcution of TSH and secondary hyperthyroidism
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Struma ovarii
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- ovarian teratoma made up of thyroid tissue
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What are the different types of thyroiditis?
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1. Hashimoto
2. Subacute (de Qurvian, granulomatous) 3. Riedel thyroiditis |
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Hashimoto Thyroiditis
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- autoimmune disorder
- slow, insiduous course - modestly enlarged and nontender thyroid - usually, patient is euthyroid at first -> then transient hyperthyroidism -> hypothyroidism develops when gland is shrunken and scarred |
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what are the histologic characeristics of Hashimoto Thyroditis?
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- massive infiltrates of lymphocytes with germinal center formation
- thyroid follicles are atrophic and Hurthle cells are prominent |
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what are Hurthle cells?
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- epithelial cells with eosinophilic granular cytoplasm
- seen in Hashimoto thyroiditis |
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which autoantibodies are assoicated with Hashimoto Thyroditis?
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- antithyroglobulin
- antithyroid peroxidase - anti-TSH receptor - anti-iodine receptor |
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what are the HLA associations with Hashimoto Thyroditis?
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- HLA-DR5
- HLA-B5 |
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what other autoimmune disorders are associated with Hashimoto Thyroditis?
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- pernicious anemia
- DM - Sjogren syndrome |
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what is subacute (de Quervain, granulomatous) thyroditis?
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- more common in women
- focal destruction of thyroid tissue and granulomatous inflammation - caused by viral infections: mumps or coxsackievirus - self-limited course: flu-like illness and pain of the thyroid |
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Reidel thyroidits
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- thyroid replacement by fibrous tissue
- unknown origin - can clinically mimic carcinoma |
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describe the bening tumors (Adenomas) of the thyroid
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- solitary
- nodulesa dn can occur in a variety of histologic patterns (follicular, Hurthle cell) - most often nonfunctional - can sometimes cause hyperthyroidism |
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List the malignant tumors of the thyroid
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1. Papillary carcinoma
2. Follicular carcinoma 3. Medullary carcinoma 4. Undifferentiated carcinoma |
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Papillary carcinoma
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- most commmon thyroid cancer
- paillary projections into gland-like spaces - have 'ground-glass' ('Orphan Annie') nuclei, calicified spheres (psammoma bodies) - better prognosis than other thyroid cancers, even with lymph node involvement |
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describe the genetic changes benhind papillary carcinoma
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- changes in chr 10- paracentric inversion of Chr 10 or reciprocal translocation between chr. 10 and 17 -> constitutively activate the TK domain of ret
- novel fusion genes are called: ret-PTC (ret and papillary thyroid carcinoma) -> constit. active TK domain |
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what can cause papillary carcinoma?
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- prior long term radiotherapy to the neck
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Follicular carcinoma
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- hsitologically: uniform follicles
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medullary carcinoma
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- originates from C cells of the thyroid
- produces calcitonin (calcium lowering hormone) - histology: sheets of tumor cells in amyloid-containing stroma - can be associated with MEN IIa and IIb |
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undifferentiated carinoma
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- foudn in older patients
- very poor prognosis |
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secretion of wht hormone is not under pituitary control?
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- PTH
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list the causes of hyperparathyroidism
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1. primary hyperparathyroidism
2. secondary hyperparathyroidism 3. tertiary hyperparathyroidism 4. 1a-hydroxylase deficeincy (vit D dependent rickets) |
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primary hyperparathyroidism
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- most often caused by parathyroid adenoma; sometimes by parathyroid hyperplasia; less often, by prodcition of THS like hromone by nonparathyroid malignant tumors
- can occur as part of MEN I and IIa |
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which tumors produce PTH-like hormone?
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- bronchgenic squamous cell carcinoma
- renal cell carcinoma |
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what are the lab findings you see in primary hyperparathyroidism?
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- hypercalcemia and hypercalciuria
- decreased serum phosphorus, decreased tubular reabsorption of phsophorus - inreased serum alkaline phosphatase - increased serum PTH |
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what are the clinical manifestations of primary hyperparathyroidism?
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- osteitis fibrosa cystica
- metastatic calcification of tissues (esp kidnies: nephrocalcinosis) - renal calculi - peptid duodenal lucer from hypercalcemia |
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what ion imbalance predisposes to peptic duodenal ulcer?
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- hypercalcemia
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osteitis fibrosa cystica
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- cystic changes to bone from osteoclastic resorption
- aka von Recklinghausen disease of bohne - fibrous replacement of resorbed bone can lead to brown tumors: non-neoplastic tumor-like masses |
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brown tumors
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- seen in osteitis fibrosa cystica
- fibrous replacment of resorbed bone |
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von Recklinghausen disease
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- Osteitis fibrosa cystica
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Secondary hyperparathyroidism
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- compensatory parathyroid hyperplasia due to decreased serum [Ca]
- most common cause: chronic renal disease - characteristics: decreased serum Ca, increased serum P, increased Alkaline phosphatases, diffuse osteoclastic bone disease, metastatic calcification - increased PTH |
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how does chronic renal failure cause secondary hyperparathyrodism?
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- vit D conversion by the kidney to biologically active 1,25 dihydroxycholecalciferol is impeded
- decreased intestinal absorption of Ca - also, increased serum P of renal disease causes decrease in free Ca |
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shorthand for 1,25 dihydroxyholecalciferol
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- 1,25(OH)2D3
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Tertiary hyperparathyrodism
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- persistent parathyroid hyperfucntion despite correction of hypocalcemia and preexisting secondary hyperparathyroidism
- often caused by development of adenoma in a previously hyperplastic gland |
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1a-hydroxylase deficiency (vit D dependent rickets)
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- impaired hydroxylation of 25-hydroxycholecalciferol is characteristic
- decreased absorption of Ca and increasd PTH secretion |
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hypoparathyroidism
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- caused by accidental excision during thyroidectomy
- also associated with congentical thymic hypoplasia (DiGeorge Syndrome) |
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DiGeorge syndrome
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inability to fight infections (immunodeficiency) associated with the absence of the thymus glands, low calcium levels associated with the absence of the parathyroid glands and abnormalities of the heart. Thymus, parathyroid glands and heart derive from the same primitive embriyonic structure and that is why these three organs are dysfunctioned together in this disease.
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what do you see in severe hypocalcemia?
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- increased neuromuscular excitability
- tetany |
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pseudohypoparathyroidism
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- similar to hypoparathyroidism, with decreased Ca, increased P, and increased PTH
- multihormone resistance involving PTH, TSH, LH, and FSH - end-organ unresponsiveness of teh kidney to PTH - shortened fourth and fifth metacarpals and metatarslas - short stature |
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what causes psudohypoparathyrodism?
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- mutations in GNAS1
- a gene encoding G proteins that mediate tissue receptiveness to hormones - both allels are expressed in multiple tissues - but in kidney and pituitary, there is expression of only the maternally inherited chr |
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what causes Chusing syndrome (hypercorticism)?
|
- increased circulating glucocorticoids, primarily cortisol
1. corticosteroid medications 2. hyperproduction of ACTH by corticotrophs of pit 3. Adrnal corticla adenoma or adrenal carcinoma 4. ectopic production of ACTH |
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what can cause ectopic production of ACTH?
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- nonpituitary carcinomas, esp small cell carcinoma of lung
- hypercorticicm cannot be suppressed by exogenous adrenal steroids - elmination of normal circadian rhythm of cortisol production |
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what is dexamethasone used for?
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- low and high dose dexamethasone (exogenous steroid) suppression tests are used to determine causes of hypercorticism
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what changes do you get to the adrenal gland in Cushing syndrome?
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- bilateral hyperplasia
- adrenal cortical atrophy - adrenal cortical adenoma or carcinoma |
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what sort of hyperplasia do you get of the adrenal gland in Cushing sydnrome?
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- bilateral hyperplasia of the zona fasciculata, when CS results from ACTH stimulation
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what sort of adrenal cortical atrophy is seen in Cushing syndrome?
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- see when exogenosu glucocorticoid medication is the cause
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adrenal cortical adenoma or carcinoma
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- can be seen in Cushing sydnrome
- adenoma is more common |
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dexamethasone suppression test
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- can suppress hypercorticism of pituitary origin
- cannot suppress hypercorticism from exogenous adrenal steroids |
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what are the clinical characteristics of Cushing syndrome?
|
- moon face
- dorsal buffalo hump - thin extremities caused by muscle wasting - skin atrophy with easy brusing - purplish straie over abdomen - hirsutism - muslce weakness, osteoporosis, amenorrhea, hypertension , hyperglycemia, psychiatric dysfunction |
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primary aldosteronism (Conn syndrome). what causes it?
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- hyperproduction of adrenal mineralocorticoids
- resutls from aldosterone producing adrenocortical adenoma (aldosteronoma) - can laso result from hyperplasia of the zona glomerulosa - rarely, caused by adrenocortical carcinoma |
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aldosteronoma
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- aldosterone- producing adrenocortical adenoma
- can cause Conn syndrome |
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what are the clinical characteristics of Conn syndrome?
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- hypertension
- Na and water retension - kypokalemia - hypokalemic alkalosis |
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secondary aldosteronism
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- secondary to renal ischemia, renal tumors, and adema (cirrhosis, nephrotic syndrome, cardiac failure)
- caused by stimulation of the renin-angiotensin, system - serum renin is increased |
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how do you differentiate primary from secondary aldosteronism?
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- see elevated renin in secondary aldosteronism
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Adrenal virilism (adrenogenital syndrome)
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- caused by congenital enzyme defects that diminish cortisol proudction and compensatory increased ACTH -> adrenal hyperplasia and androgenic steroid production
1. 21-hydroxylase deficiency 2. 11-hydroxylase deficinecy - can also be caused by tumors of the adrenal cortex |
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21-hydroxylase deficiency
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- most common cause of adrenal virilism
- can cause salt loss and hypotension |
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11-hydroxylase deficeincy
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- less common cause of adrenal virilism
- results in salt retention and hypertension |
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what are the clinical characteristics of adrenal virilism?
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- virilsim in females
- precocious puberty in males |
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general considerations of hypocorticism
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- can be of primary adrenal cause or secondary to hypothalamic or pituitary dysfunction
- deficeincy of glucocorticoids (primarily cortisol), often with associated minerolocorticoid deficeincy, is characteristic |
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Addison disease (primary adrenocortical deficiency)
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- most commonly due to idiopathic adrenal atrophy (autoimmune lymphocytic adrenalitis)
- can laos be aused by TB, metastatic tumor, and infetions - hypotension, increased skin pigmentation, decreased serum Na, Cl, glucose and HCO3- - increased serum K |
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Waterhouse- Friderichsen syndrome
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- catastropic adrenal insufficiency and vascular collapse
- due to hemorrhagic necrosis of the adrenal cortex - associated with DIC - due to meningococcemia, most often associated with meningococcal meningitis |
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what are the tumors of the adrenal medulla?
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1. pheochromocytoma
2. neuroblastoma |
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pheochromocytoma
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- derived from chromaffin cells of the adrenal medulla
- msot often benign; 10% is malignant - increased urinary excretion of catecholamines and their metabolites (metanephrine, normetanephrine, and vanillylmandelic acid - can cause hyperglycemia - can be part of MEN IIa, IIb |
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what can pheochromocytoma be associated with?
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- neurofibromatosis
- von Hippel-Lindau disease - MEN IIa or IIb (III) |
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von Hippel-Lindau disease
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inherited genetic condition involving the abnormal growth of tumors in parts of the body which are particularly rich in blood supply.
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