the endocrine system for dental students dr ibrahim hassan alzahrani frcpath -uk chairman of...
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The Endocrine system The Endocrine system for dental studentsfor dental students
DR IBRAHIM HASSAN DR IBRAHIM HASSAN ALZAHRANI FRCPath -UKALZAHRANI FRCPath -UK Chairman of Pathology Chairman of Pathology
DepartementDepartementFaculty of Medicine Faculty of Medicine
CONTENTS:CONTENTS:• Pituitary gland
– Hypopituitarism– Hyperpituitarism– Posteroir pituitary syndromes
• Thyroid galnd– Hypothyrodism– Hyperthyrodism– Goiter– Thyrodidtis– Tumors
• Parathyroid glands– Hyperparathyroidism – Hypoparathyroidism
• Adrenal gland – Cortex
– Medulla . Tumors
• Multiple endocrine neoplasia • Endocrine pancreas (D.M )
THYROID GLANDTHYROID GLAND
• This is the normal appearance of the thyroid gland on the anterior trachea of the neck..
Normal thyroid seen microscopically consists of follicles lined
by a cuboidal epithelium and filled with pink, homogenous colloid
Hypothyroidism:Hypothyroidism:
• Causes:– structural or functional– 95% are due to:
• Surgical or radiation ablation• Hashimoto’s thyroiditis• Primary idiopathic hypothyroidism
CretinismCretinism
• This is uncommon disease of childhood due to failure of thyroid to synthesize thyroid hormones hypothyroidism
Myxedma, cretenismMyxedma, cretenism
• Neurologic & myxedematous patterns
• Clinically:– mental retardation– growth retardation (short stature)– coarse facial features with dry skin and
protruding tongue– muscle weakness and umbilical hernia
MyxedemaMyxedema• Hypothyroidism in adult.• - Clinically:
– appear insidiously & subtle– lethargy & weakness with slow speech– cold intolerance with cool & rough skin– menstrual problems & psychosis– cardiac changes: cardiac output, hypertrophy,
(myxedema heart), pericardial effusion– deposition of mucopolysaccharides in
connective tissue– atherosclerosis ( cholesterol)
Hyperthyroidism Hyperthyroidism
• Excess thyroid hormone (Thyrotoxicosis)• Causes:
– primary diffuse toxic hyperplasia (Grave’s disease) > 95%
– toxic multinodular goiter– toxic adenoma– certain form of thyroiditis– secondary to pituitary or hypothalamic
lesion
•Clinical features:
• nervousness and emotional instability• menstrual changes• fine tremors of the hands• heat intolerance with warm skin and
sweating• weight loss despite a good appetite
• Eye changes: (exopthalmos, widened palpebral fissures, staring gaze)
• Cardiac changes: (tachycardia, palpitations, atrial fibrillation and thyrotoxic cardiomyopathy----- cardiac failure)
• skeletal muscle atrophy and fatty infiltration• lymphadenopathy• fatty change of the liver• Osteoporosis
ThyrotoxicosisThyrotoxicosis
Upper, thyrotoxicosis
Lower, after treatment
GoiterGoiter
• Goiter simply means enlarged thyroid
Diffuse GoiterDiffuse Goiter
• Characterized by diffuse symmetrical enlargement of thyroid (200 - 300 gm) with normal thyroid function.
• Hypofunction may occur early in the course .
• Usually occurs in: Endemic areas ( iodine & goiterogens) or
• Sporadic (physiological ,autoimmune , familial ).
Multinodular GoiterMultinodular Goiter
• Characterized by nodular asymmetrical enlargement of thyroid (up to 1000 gm)
• Slowly evolves from diffuse goiter.It can be toxic or non-toxic
Solitary thyroid noduleSolitary thyroid nodule• Size (symptoms)• Possible hyperfunction• Usually colloid nodule >70%• Adenoma 20-30%• Carcinoma <5% - Radioactive iodine (Hot & cold nodule)• FNA & biopsy• Thyroid function
Solitary thyroid noduleSolitary thyroid nodule
• Invisigations: • thyroid hormons: (T3,T4,TSH)• radiological examinations : * ultrasound (cystic/solid) * radioactive iodine (cold/hot)• Fine needle aspiration cytology
GRAVE’S DISEASEGRAVE’S DISEASE• Primary Diffuse Toxic Hyperplasia• The most common cause of thyrotoxicosis• It is an autoimmune disease• Classically shows:
– 1-Exopthalmos (proptosis)– 2-Dermopathy (pretibial myxedema)– 3-Hyperthyroidism
• Common in ♀ 3rd & 4th decade• ♀ : ♂ = 10 : 1• HLA – DR3 & Familial predisposition• Other autoimmune diseases may occur
•Pathogenesis• B-cells secrete autoantibodies
against mainly TSH – Receptors (Abs. against microsomes, thyroglobulin, T3 & T4 can be seen)
MorphologyMorphology
• Gross: diffuse symmetrical enlargement of thyroid
THYROIDITISTHYROIDITIS
• Hashimoto’s thyroiditis• Subacute
(granulomatous,DeQuervian) thyroiditis
• Chronic lymphocytic (painless) thyroiditis
• Riedel’s fibrous thyroiditis
Hashimoto’s thyroiditisHashimoto’s thyroiditis
• This is an autoimmune most common type of thyroiditis characterized by symmetrical modesty enlarged thyroid responsible for most cases of primary goiterous hypothyroidism.
Pathogenesis Pathogenesis
• B cells autoantibodies against microsomes and thyroglobulin.
• Cell-mediated destruction of the gland
• ♀ : ♂ = 10 : 1 middle-aged • Higher incidence of autoimmune
disease
Clinical CourseClinical Course
• Euthyroid--- hypothyroid• Moderate goiter• Hashitoxicosis(hyperthyroidism)
occasionally• 5% - B cell lymphoma or rarely
papillary carcinoma of thyroid
THYROID TUMOURSTHYROID TUMOURS
1-BENIGN: Follicular adenoma
2-MALIGNANT:• Carcinoma of thyroid
– Papillary carcinoma– Follicular carcinoma– Medullary carcinoma– Anablastic carcinoma
–Lymphoma Others – rare (sq. ca, sarcomas, metastasis)
ADENOMAADENOMA
• Always follicular adenoma• No papillary adenoma of thyroid.• Solitary & encapsulated.• No capsular invasion.• Histology: Follicles –> macro (colloid), micro
(fetal), normal size (simple), trabecular (embryonal).
• Sometimes composed of Hürthl cells
(oncocytic) Hurthle cell adenoma.
ADENOMAADENOMA
ADENOMAADENOMA
CARCINOMA OF CARCINOMA OF THYROIDTHYROID
• Causes:– Ionizing radiation– Hashimoto’s thyroiditis– Grave’s disease?
Papillary CarcinomaPapillary Carcinoma 60-70%60-70%
• The most common type• Young age 20-50y , F:M=3:1• Forming papillae and psammoma bodies• Cells typically show ground-glass
appearance with clear grooved nuclei “Orphan Annie” and intranuclear inclusion
• 50% at presentation Cervical LN metastasis
• Haematogenous spread is rare (not common)
•Follicular variant of papillary carcinoma : No papillary formation . The nuclei shows typical nuclear ground glass appearance of papilary crcinoma.
•Grow slowly with indolent course•Occult microscopic variant
Papillary CarcinomaPapillary Carcinoma
Follicular CarcinomaFollicular Carcinoma• Macroscopically often encapsulated
similar to adenoma • Histologically : composed of follicles
with no papillary formation and no groundglass nuclear changes.
• sometimes the cells are oncocytic (Hurthle cell carcinoma).
Follicular CarcinomaFollicular Carcinoma• Haematogenous spread (lung, bone,
liver. . )• Poorer in prognosis than papillary
carcinoma.• Represent approximatly 15%• Most patients are >40y • TYPES:
1- minimally invasive FC. 2- widely invasive FC.
Medullary Carcinoma of Medullary Carcinoma of
thyroid <5%thyroid <5%
• Derived from calcitonin – secreting C-cells
• Characterized by formation of amyloid material from calcitonin, surrounded by small to medium sized cells with round to spindle shaped nuclei forming sheets, nests or cords
Medullary Carcinoma Medullary Carcinoma
amyloid
Medullary CarcinomaMedullary Carcinoma• It has slow but progressive growth • Both lymphatic and hematogenous
metastasis occurs• 10-20% are familial, multicenteric in
young age, associated with MEN 2&3 • Immuno: +ve calcitonin• 80-90% sporadic, solitary, old age
Anablastic carcinoma 5-10%Anablastic carcinoma 5-10%
0ccurs in patient > 60 y• Poorly differentiated, highly malignant tumour
usually forms bulky necrotic mass often disseminate extensively through blood
• death occurs within 1-2 years (<10% survive for 10y)
•Histological variants:
• Giant cells, spindle cells(sarcomatoid), squamoid cells
PARATHYROID GLANDPARATHYROID GLAND
PARATHYROID GLANDPARATHYROID GLAND
HyperparathyroidismHyperparathyroidism - Primary Hyperparathyroidism: Increase PTH due to parathyroid lesion
(Adenoma/hyperplasia) Hypercalcaemia
PTH Hypercalcaemia : osteoclast to mobilize Ca++ from bone Ca++ reabsorption in the kidney Ca++ absorption in Git .through vit .D. excretion of phosphate in urine .
• Part of MEN I & II• F : M = 3 : 1 > 40y
Clinical featuresClinical features
• Asymptomatic (lethargy&weakness)• Bone pain (osteomalacia, osteoporosis &
osteitis fibrosa cystica/brown tumor)• Renal stones (nephrolithiasis)• Nephrocalcinosis• Metastatic calcification (blood vessels, soft tissue
& & joints)• Abdominal pain (peptic ulcer,pancreatitis) and
mental change
Parathyroid adenomaParathyroid adenoma
adenoma
normal
Adenoma & Hyperplasia In adenoma one gland, Hyperplasia >one gland
• Frozen section (intraoperative consultation) required to confirm presence of parathyroid tissue.
Carcinoma of parathyroid: * Rare – Invasion and metastasis– Bands of collagen in the stroma– High mitotic figures.
Parathyroid carcinomaParathyroid carcinoma
MULTIPLE ENDOCRINE MULTIPLE ENDOCRINE NEOPLASIANEOPLASIA
MULTIPLE ENDOCRINE MULTIPLE ENDOCRINE NEOPLASIA (NEOPLASIA (MEN)MEN)
• MEN are syndromes characterized by hyperplasic or neoplastic involvement of at least two endocrine glands and sometimes associated with non-endocrine lesions.
• MEN I: Wermer ’ s Syndrome– Parathyroid adenom/hyperplasia .– Pituitary adenoma .– Pancreatic lesions (hyperplasia
adenoma , carcinoma )– Mutant gene(MEN1) locus at 11q13– Autosomal dominnant
• MEN II (IIa):Sipple Syndrome– Medullary carcinoma of thyroid– Pheochromocytoma .– Occasionally parathyroid lesion
(30%) – Mutant gene locus at 10q11.2
(RET proto-oncogen)– Autosomal dominant
• MEN III (IIb): William syndrome:
similar to MEN II plus – Marfanoid bodily habitus– Multiple mucocutanenous
ganglioneuromas– Parathyroid involvement :
(none/rare).