27. skin Flashcards
ant. pituitary pathologies include
pit. adenoma
hypopituitarism
Pituitary Adenoma type size and causes
6-10% of all symptomatic intracraneal neoplasms
Most common cause of hyperpitutarism
Functional (hyperpituitarism) or nonfunctional
Childhood to old age (peak 35-60yrs)
Microadenoma <1cm and macroadenoma >1cm
Circumscribed to invasive (30%)
Clinical Manifestations of Pituitary adenoma
Hyperpituitarism or hypopituitarism
Mass effects (tumors)
Sellar expansion, bony erosion, disruption of diaphragma sella), visual field abnormalities (optic chiasm compression), raised intracranial pressure (headache, nausea, vomiting)
Pitutary apoplexy
Pituitary apoplexy
Ancient Greek ἀποπληξία (apoplexia) ‘a striking away’) is rupture of an internal organ
“sudden death” of the pituitary gland, usually caused by an acute ischemic infarction or hemorrhage.
“ pituitary stroke”
A pre-existing pituitary adenoma
Neurosurgical emergency
Prolactinoma
Composed of lactotropic cells
~ 30% of all pituitary tumors
Women may present with oligomenorrhea, amenorrhea, galactorrhea, loss of libido or infertility
Men often have less symptoms than women (sexual dysfunction, visual problems, or headache)
Somatotropic adenomas
causes what 2
metabolic causes and why
Growth hormone
Gigantism (BEFORE epiphyseal closure) or Acromegaly (AFTER epiphyseal closure)
75% of clinically apparent are macroadenoma
Causes metabolic disturbances, such as hyperglycemia (secondary diabetes mellitus) and hypercalcemia
why GH/somatotropic adenoma causes secondary DM
GH induce liver gluconeogenesis
somatotropic adenoma diagnosed by
Diagnosed by ↑GH and IGF-1, lack of GH suppression by oral glucose
acromegaly symptoms
teeth gapping
increased hands size
mandibulat enlargement
Pituitary dwarfism
cause
and differential
Severe deficiency of GH in children before growth is completed
Isolated GH deficiency is commonly the result of an inherited AR disorder
Inherited pituitary dwarfism appear after one year of age; retardation in growth of bones and episodes of hypoglycaemia
cretinism
plus mental retardation
HYPOPITUITARISM
A, Insufficient production ol hormones by the anterior pituitary gland; symptoms arise when > 75% of the pituitary parenchyma is lost,
B, Causes include
Pituitary adenomas (adults) or craniopharyngioma (children)—due to mass
effect or pituitary apoplexy (bleeding into an adenoma)
Sheehan syndrome—
define
pathogenesis
pregnancy-related infarction of the pituitary gland
i. Gland doubles in size during pregnancy, but blood supply does not increase
significantly; blood loss during parturition precipitates infarction.
Simmond’s disease
without preceding pregnancy and/or in males
infarction of pit.
Empty sella syndrome—
define
types
congenital defect of the sella
Cause panhypopituitarism
Primary is due to incomplete diaphragma sella (congenital defect of the sella)herniation of subarachnoid space into the sella turcica
Secondary is a result of Sheehan’s syndrome, infarction and scarring in an adenoma, irradiation damage, or surgical removal of the gland
Pituitary gland is “absent” (empy sella) on imaging
Craniopharyngioma
define
age
causes
benign/mal
gene mutation
fluid within looks like
Derived from remnants of Rathke pouch (odontogenic epithelium)
Commonly affects children and young adults
Headache, hypopituitarism, and visual field disturbances
Benign but tends to recur after resection
β-catenin (CTNNB1) gene mutations
“motor oil”-like
fluid within tumor
Posterior pituitary pathology
Syndrome of inappropriate antidiuretic hormone(SIADH)
Diabetes insipidus (DI)
Syndrome of inappropriate antidiuretic hormone(SIADH)
define
cause
complication
Syndrome of inappropriate antidiuretic hormone(SIADH)
Excessive production of ADH
Retention of water results in hyponatremia and low serum osmolality neuronal swelling and cerebral edema (Mental status changes and seizures)
Cause; any lung disease(like infection), any CNS diseases(like trauma), small cell lung carcinoma and drug (oxytocin ,TCAD)
Diabetes insipidus (DI)
define type
Neurogenic or central DI
Insufficient secretion of ADH
Causes; Tumor, Multifocal LCH, tuberculosis meningitis, trauma, surgery
Nephrogenic DI
Inadequate response of the renal tubules to ADH
Cause; drug like Li and demeclocycline, genetic disorder (X linked recessive), Chronic renal disease, sickle cell anemia
to check for DI
Water deprivation test fails to increase urine osmolality in central DI.
congenital thyroid pathologies
Thyroid dysgenesis
Dyshormonogenetic goiter
Thyroglossal duct cysts and sinus
Thyroid dysgenesis
define and percentage
Anomalies in the anatomic development of the thyroid, including thyroid gland proper abnormalities (agenesis, hemiagenesis and hypoplasia) and ectopic thyroid tissue.
~ 80% of cases of 1ᵒ congenital hypothyroidism
Dyshormonogenetic goiter
sex
cause by or due to
Inborn errors of thyroid hormone synthesis most frequent due to TPO and TG genes mutation
~ 20% of primary congenital hypothyroidism
F > M (2:1)
Thyroglossal duct cysts and sinus
Cystic dilation of thyroglossal duct remnant
thyroditis types
hashimoto
reidels fibrosing thyroditis
subacute granulomatous/ dequervain thyroditis
Hashimoto thyroiditis
define
age
sex
gene mutations
assoc. with
pathogenesis
Chronic autoimmune disease characterized by immune destruction of the thyroid gland and hypothyroidism.
1st described by the Japanese physician Hakaru Hashimoto in 1912.
Peak age 45 - 65 years
F:M= 10 - 20 : 1
HLA-DR3, HLA-DR5
Associated with other autoimmune disease such as SLE, Sjögren’s syndrome, Type I DM and rheumatoid arthritis, Addison disease or pernicious anemia
Antithyroglobulin (TG)
Antithyroid peroxidase(TPO)
Antimicrosomal antibodies (AMA)
what is seen in histology of hashimoto that differentiates it from subacute lymphocytic
hurthle cells and fibrosis
esosinophilic metaplasia of cells of the follicle
Most common cause of hypothyroidism in iodine-sufficient regions
hashimoto
……………………. presents as an enlarged thyroid gland in late stage
marginal zone lymphoma
Subacute Lymphocytic (Painless) Thyroiditis
define
seen in
Autoimmune disease with pathologic features that resemble Hashimoto thyroiditis
Unlike Hashimoto thyroiditis, fibrosis and Hürthle cell metaplasia are not prominent
~ 5% of women in postpartum period (postpartum thyroiditis)
Subacute granulomatous thyroiditis (de Quervain)
define
age
sex
granulomatous thyroditis that follow viral infection
Self-limited disease often following a flu-like illness (eg, viral infection)
Peak ages of 40 – 50 years
F:M =4 : 1
The most common cause of thyroid pain (de Quervain is associated with pain)
………………. May be thyrotoxic early in course, followed by hypothyroidism (permanent in ~15% of cases).
de quervain
Riedel thyroiditis
define
associated with
thyroid presentation
differential
and how to cancel that ddx
chronic inflammation with extensive fibrosis of the thyroid gland
IgG4-related rare disease Shows a
slight predilection for females with most patients being middle-aged.
Hard (‘hard as wood’, ‘stony hard’, or ‘iron hard’), and fixed thyroid mass clinically simulates a thyroid carcinoma. but patients are younger (40s), and malignant cells are absent.
Associated with fibrosis in other sites in the body, such as the retroperitoneum
hypothyroidism causes 2
primary
genetic
iodine deficiency
drugs
and secondary central
Iodine deficiency
Occurs in highland area far from sea water.
Deficiency of iodine in food and water is worldwide still the most common cause of hypothyroidism.
200 million people worldwide continue to be at risk for severe iodine deficiency.
Iatrogenic
Surgical removal of thyroid
Drugs that cause unwanted hypothyroidism, such as sulphonylureas, resorcinol, lithium and amiodarone
Surprisingly enough, iodides in large quantities inhibit the organic binding of iodine (i.e hypothyroidism) and produce an iodide goiter called
Wolff–Chaikoff effect
Clinical presentation of hypothyroidsm
in children and adults
Neonate and infant develop critinism
Older child and adult develop myxedema
Myxedema
clinical features are based on decreased basal metabolic rate and sympathetic nervous system activity
loss of lateral eyebrow hair
puffy skin due to accumulation of mucopolysacharides
carpal tunnel syndrome
Myxedema coma
Severe hypothyroidism in long standing untreated disease precipitated mainly by infection and cold exposure
Treatment: IV fluid, corticosteroid, T4 and T3 and hot blancket.
lab findings of myxedema coma
hypoglycemia
hyponatremia
hypoxemia
hypercapnia
Cretinism
Characterized by mental retardation (cretinism), short stature (thyroid dwarfism), coarse facial features, enlarged tongue, and umbilical hernia.
Causes include maternal hypothyroidism during early pregnancy, thyroid dysgenesis, dyshormonogenetic goiter, and iodine deficiency.
Thyroid storm
Extreme form of hyperthyroidism
Precipitated by infection, trauma, surgery and stress
Delirium, coma, high grade fever, hypotension, CHF
30% mortality
thyroid opthalmology
retraction of upper eye lid
lid lag of upper eyelid
inability to converge
Hyperthyroidism (thyrotoxicosis)
define
causes what
and how
Hypermetabolic state that results from an excess of free thyroid hormones (T3 and T4) in blood.
Increases basal metabolic rate (due to increased synthesis of Na+ - K+ ATPase)
Increases sympathetic nervous system activity (due to increased expression of receptors)
causes of hyperthyroidism
Graves disease
multinodular goitor
Graves disease
define
age
causes what and how
The most common cause of endogenous hyperthyroidism
Autoimmune disorder
90% of patients have Thyroid stimulating immunoglobulin (TSI)
Peak age 20 to 40 years
M:F= 1:10.
Increased risk for other autoimmune diseases, such as SLE, pernicious anemia, type 1 diabetes, and Addison disease.
graves triad
dermopathy
opthalmopathy
diffuse goiter
lady seeing grave
why exopthalmosis and periorbital myxedema
Fibroblasts behind the orbit and overlying the shin express the TSH receptor. TSI and CD4+ cytokines results in glycosaminoglycan (chondroitin sulfate and hyaluronic acid) accumulation, inflammation, fibrosis, and edema leading to exophthalmos and pretibial myxedema.
histologic finding in graves diesease
scalloping of colloid
colloid normally cicle but now irregular