Download Pathology of the Endocrine System Topics

4/1/2014 Pathology of the Endocrine System
นายแพทย ดร.ณตพล ศุภณัฐเศรษฐกุล
ภาควิชาพยาธิวิทยา
คณะแพทยศาสตร มหาวิทยาลัยนเรศวร
4 เมษายน พ.ศ. 2557
Topics
• Introduction • Diseases of the Endocrine glands – Pituitary gland – Thyroid gland – Parathyroid glands – Endocrine pancreas – Adrenal cortex – Adrenal medulla
1 4/1/2014 Introduction
• Endocrine = (Gr.) endo + krinein (inside) (to secrete)
• Primary function of the endocrine glands is to produce hormone to regulate the functions of other cells or organs • “Ductless glands” (ตางจาก Exocrine gland) • “Autocrine, Paracrine, Endocrine effects” • “Endocrinologist” Endocrine Glands
•
•
•
•
•
Pituitary gland Thyroid gland Parathyroid glands Endocrine pancreas (Islets of Langerhans) Adrenal gland – Adrenal cortex – Adrenal medulla
2 4/1/2014 Pituitary Diseases
• Pituitary Gland • Pituitary hyperfunction – Pituitary adenomas • Pituitary hypofunction – Pituitary insufficiency 3 4/1/2014 Pituitary Gland
• Located intracranially at “sella turcica” at base of the cranium • Anterior pituitary – Posterior pituitary • Connected to the hypothalamus via a stalk Pituitary Gland
• Anterior pituitary (Adenohypophysis) : Growth hormone (GH) Prolactin (PRL) Adrenocorticotropic hormone (ACTH) Gonadotropins (Follicle stimulating hormone (FSH) and Luteinizing hormone (LH) – Thyroid‐stimulating hormone (TSH) –
–
–
–
• Posterior pituitary (Neurohypophysis) : – Oxytocin – Antidiuretic hormone (ADH)
4 4/1/2014 Pituitary Hyperfunction
• Pituitary adenomas • Prolactinomas (lactotropic adenomas) is most common • Cause Hyperprolactinemia – Amenorrhea (lack of menstruation) – Galactorrhea (milk secretion unrelated to pregnancy) – Infertility (inhibit normal ovulation)
• Somatotropic adenomas : Growth hormone (GH) – Before closure of the epiphyseal plate : Gigantism – After closure of the epiphyseal plate : Acromegaly 5 4/1/2014 Pituitary Adenoma Acromegaly
6 4/1/2014 Gigantism
Pituitary Hypofunction
• Panhypopituitarism (pituitary insufficiency) – General weakness, cold intolerance, weight loss, hypotension, amenorrhea, impotence, dwarfism • Selective pituitary hypofunction • Diabetes insipidus – A lack of antidiuretic hormone (ADH) secondary to destructive lesions of the hypothalamus or pituitary stalk or tumors of the posterior pituitary – Secrete large amounts (5‐6 L/day) of hypotonic urine
7 4/1/2014 Thyroid Diseases
•
•
•
•
Thyroid gland Hyperthyroidism Hypothyroidism Thyroid Neoplasms
Thyroid Gland
• An endocrine gland located in the neck • Two types of cells : Follicular cells and C cells • Follicular cells – Thyroxine or tetraiodothyronine (T4) – Triiodothyronine (T3) • C cells – Calcitonin involved in maintenance of calcium homeostasis
8 4/1/2014 Hypofunction & Hyperfunction 9 4/1/2014 Hyperthyroidism
• Hyperthyroidism or thyrotoxicosis is a hypermetabolic state that results from an excess of free thyroid hormone (T3 and T4) in blood • Graves’ disease (autoimmune disease) – Antibodies to the TSH receptor on the surface of thyroid follicular cells – Diffusely enlarged gland with lymphoid follicles – Tachycardia, restlessness, sweating, palpitation, tremor, increased appetite, weight loss – Exophthalmos (bulging eyes) and pretibial myxedema http://www.immuneweb.com/images/20/figure20‐04.jpg
10 4/1/2014 Exophthalmos
http://www.beltina.org/pics/exophthalmos.jpg
Hypothyroidism
• Congenital developmental defects – Thyroid dwarfism – Cretinism (mental retardation) • Autoimmune Hashimoto’s thyroiditis (most common cause of hypothyroidism) • Thyroidectomy • Iodine deficiency : nodular goiter • Sleepy, lacks of mental alertness, bradycardia, cold intolerance, constipation, muscle weakness • Myxedema : increased connective tissue deposition (glycoaminoglycans, hyaluronic acid, and other mucopolyscaccharides)
11 4/1/2014 Dwarfism
http://healthtalk.info/wp‐content/uploads/Fig‐2‐cretinism.jpg
http://howshealth.com/wp‐content/uploads/2010/11/cretinism.jpg
Clinical Features Myxedema
http://healthtalk.info/wp‐content/uploads/Fig‐3‐
myxedema‐thyroid‐hormone‐deficiency‐
hypothyroidism.jpg
Graves’ dis.
http://www.checkbook.org/sitemap/health/Gr
aves_Disease/..%5CGraphics%5CGraves_eyes.j
pg
12 4/1/2014 Goiter
http://s1.hubimg.com/u/2822516_f520.jpg
Thyroid Neoplasms
• Follicular adenoma : most common benign tumor – Small, well encapsulated with fibrous tissue, composed of thyroid follicles • Papillary carcinoma : 80% of all malignant thyroid tumors – Four times more common in women than in men – Tends to metastasize to the local lymph nodes 13 4/1/2014 Follicular Adenoma
1
Follicular Adenoma
Fibrous capsule
Follicular cells
2
14 4/1/2014 Papillary carcinoma of thyroid
1
Papillary carcinoma of thyroid
2
15 4/1/2014 Diseases of the Parathyroid Glands
• Parathyroid Glands • Hyperparathyroidism • Hypoparathyroidism Parathyroid Glands
• Usually, 4 glands behind the thyroid • Secrete parathormone (PTH) in response to a decrease in plasma calcium level • PTH stimulates the release of calcium from bone and also resorption of calcium from urine in the kidney Æ to elevate calcium concentration in blood 16 4/1/2014 Hyperparathyroidism
• Primary : parathyroid hyperplasia, neoplasia • Secondary : compensatory mechanism triggered by hypocalcemia caused by chronic renal failure, hypovitaminosis D • Excess of PTH in the circulation • Hypercalcemia : muscle weakness, cardiac arrhythmia, nephrocalcinosis, urolithiasis • Bone weakness and prone to fracture
17 4/1/2014 Parathyroid Hyperplasia & Neoplasia 18 4/1/2014 Hypoparathyroidism
• Most commonly occurs after all 4 glands are totally removed during cancer surgery of the neck • Hypocalcemia : hypocalcemic tetany (muscular spasm), irregular heart beat, cardiac arrest
Endocrine pancreas
• The endocrine cells are arranged into islets of Langerhans, scattered through the entire organ but are most prominent in the tail of pancreas • The islets of Langerhans contain several endocrine cell types – Alpha cells (20%) secrete glucagon – Beta cells (70%) secrete insulin – Delta cells (10%) secrete somatostatin or pancreatic polypeptide (PP)
19 4/1/2014 http://www.gopetsamerica.com/anatomy/illustrations/pancreas.jpg
http://embryology.med.unsw.edu.au/histology/endocrine/pan20he.jpg
http://wikis.lib.ncsu.edu/images/8/80/Endoexoc.gif
20 4/1/2014 Diabetes mellitus (DM)
• (Gr) = diabetes + mellitus (sweet) • diabetes = “Pass through” to denote polyuria (large amount of urine) • DM caused by – Absolute or relative deficiency of insulin – Target tissue resistance to insulin • Type 1 DM (5‐10%) children and adolescents • Type 2 DM (90‐95%) overweight adults
Clinical features of DM
•
•
•
•
•
•
Hyperglycemia Glycosuria Æ Osmotic diuresis Æ Polyuria Polydipsia Polyphagia Muscle wasting and weight loss Increase lipolysis Æ ketone body formation Æ ketoacidosis
21 4/1/2014 Complications of DM
• Cardiovascular system – Atherosclerosis, coronary heart disease, stroke – Artery occlusion : DM foot gangrene • Kidneys – Glomerulosclerosis, pyelonephritis – Renal ischemia, renal failure • Eyes – Retinal microaneurysm, hemorrhage – Cataract • Nervous system – Peripheral neuropathy (sensory and motor deficits) • Immune system – Prone to infection (immunocompromised)
Atherosclerosis
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Atherosclerosis,_aorta,_gross_pathology_
PHIL_846_lores.jpg/230px‐Atherosclerosis,_aorta,_gross_pathology_PHIL_846_lores.jpg
22 4/1/2014 DM Foot gangrene
Diabetic nephropathy
http://1.bp.blogspot.com/_8HtJsALJ3Q4/TNK37lr9wLI/AAAAAAAAADc/TvtyKgaDodo
/s1600/Diabetic+Nephropathy+photo.JPG
23 4/1/2014 http://whatisdiabetesmellitus.org/wp‐
content/uploads/2011/11/Diabetic_Retinopathy_Symptoms.jpg
Adrenal Gland
• Attached to the upper pole of each kidney • Adrenal cortex • Adrenal medulla
http://www.georgiahealth.edu/medicine/phy/raineylab/images/webfigure1.jpg
24 4/1/2014 Diseases of the Adrenal Cortex
•
•
•
•
Adrenal Gland Adrenal Cortex Adrenocortical Hyperfunction Adrenocortical Hypofunction
Adrenal Cortex
•
•
•
•
Consists of 3 zones Zona glomerulosa – mineralocorticoids (e.g. aldosterone) Zona fasciculata – glucocorticoids (e.g. cortisone) Zona reticularis – sex steroids (e.g. estrogens and androgens) 25 4/1/2014 http://humanphysiology2011.wikispaces.com/file/view/structure_of_adrenal_gland
s.jpg/198568168/structure_of_adrenal_glands.jpg
Adrenocortical Hyperfunction
• Hyperaldosteronism (Conn’s syndrome) – Hypersecretion of mineralocorticoids (aldosterone) • Hypercorticolism (Cushing’s syndrome) – Hypersecretion of glucocorticoids (cortisol) – Most common of these three syndromes • Adrenogenital syndrome – Hypersecretion of adrenal sex steroids (androgens)
26 4/1/2014 Cushing’s syndrome
• Excessive production of cortisol caused by – Adrenocortical tumors : adenoma, carcinoma – Exogenous corticosteroids • Cushing’s disease : hypercortisolism caused by hypersecretion of the ACTH either from – pituitary adenoma or – small‐cell lung cancer (paraneoplastic) • Clinical features : Central obesity, moon face, buffalo hump, hypertension, thinning of the skin and striae 27 4/1/2014 Adrenocortical Adenoma 28 4/1/2014 Adrenocortical Hypofunction
• Adrenal insufficiency or Addison’s disease • Caused by autoimmune adrenalitis, infection (tuberculosis, histoplasmosis), metastatic tumors (breast, lung) • Clinical features: fatigue, weight loss, hypotension, syncope, cannot tolerate stress, metabolic disturbance, personality change 29 4/1/2014 Disease of the Adrenal Medulla
• Adrenal Medulla – Epinephrine, Norepinephrine in ANS • Neuroblastoma – malignant tumor in children • Pheochromocytoma – benign tumor causing secondary hypertension in the young
30 4/1/2014 References
• Damjanov I., “Pathology for the Health Professions, 4th edition.”, Elsevier Saunders, Missouri, 2012, page 377 – 393. 31