The Endocrine system for dental students DR IBRAHIM HASSAN ALZAHRANI FRCPath -UK Chairman of Pathology Departement Faculty of Medicine

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The Endocrine system for dental studentsDR
IBRAHIM HASSAN ALZAHRANI FRCPath -UK Chairman of
Pathology DepartementFaculty of Medicine
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CONTENTS

• Pituitary gland
• Hypopituitarism
• Hyperpituitarism
• Posteroir pituitary syndromes
• Thyroid galnd
• Hypothyrodism
• Hyperthyrodism
• Goiter
• Thyrodidtis
• Tumors
• Parathyroid glands
• Hyperparathyroidism
• Hypoparathyroidism

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• Adrenal gland
• Cortex
• Medulla
• . Tumors
• Multiple endocrine neoplasia
• Endocrine pancreas (D.M )

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THYROID GLAND
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• This is the normal appearance of the thyroid
  gland on the anterior trachea of the neck..

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Normal thyroid seen microscopically consists of
follicles lined by a cuboidal epithelium and
filled with pink, homogenous colloid
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Hypothyroidism

• Causes
• structural or functional
• 95 are due to
• Surgical or radiation ablation
• Hashimotos thyroiditis
• Primary idiopathic hypothyroidism

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Cretinism

• This is uncommon disease of childhood due to
  failure of thyroid to synthesize thyroid hormones
  ? hypothyroidism

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Myxedma, cretenism
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• Neurologic myxedematous patterns
• Clinically
• mental retardation
• growth retardation (short stature)
• coarse facial features with dry skin and
  protruding tongue
• muscle weakness and umbilical hernia

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Myxedema

• 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)

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Hyperthyroidism

• Excess thyroid hormone (Thyrotoxicosis)
• Causes
• primary diffuse toxic hyperplasia (Graves
  disease) gt 95
• toxic multinodular goiter
• toxic adenoma
• certain form of thyroiditis
• secondary to pituitary or hypothalamic lesion

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• 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

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• 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

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Thyrotoxicosis

• Upper, thyrotoxicosis
• Lower, after treatment

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Goiter

• Goiter simply means enlarged thyroid

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Diffuse 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 ).

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Multinodular Goiter

• Characterized by nodular asymmetrical enlargement
  of thyroid (up to 1000 gm)
• Slowly evolves from diffuse goiter.It can be
  toxic or non-toxic

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Solitary thyroid nodule

• Size ?(symptoms)
• Possible hyperfunction
• Usually colloid nodule gt70
• Adenoma 20-30
• Carcinoma lt5
• ? - Radioactive iodine (Hot cold nodule)
• FNA biopsy
• Thyroid function

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Solitary thyroid nodule

• Invisigations
• thyroid hormons (T3,T4,TSH)
• radiological examinations
• ultrasound (cystic/solid)
• radioactive iodine (cold/hot)
• Fine needle aspiration cytology

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GRAVES 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

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• Pathogenesis
• B-cells secrete autoantibodies against mainly TSH
  Receptors (Abs. against microsomes,
  thyroglobulin, T3 T4 can be seen)

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Morphology

• Gross diffuse symmetrical
  enlargement of thyroid

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THYROIDITIS

• Hashimotos thyroiditis
• Subacute (granulomatous,DeQuervian) thyroiditis
• Chronic lymphocytic (painless) thyroiditis
• Riedels fibrous thyroiditis

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Hashimotos thyroiditis

• This is an autoimmune most common type of
  thyroiditis characterized by symmetrical modesty
  enlarged thyroid responsible for most cases of
  primary goiterous hypothyroidism.

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Pathogenesis

• B cells ? autoantibodies against microsomes and
  thyroglobulin.
• Cell-mediated destruction of the gland
• ? ? 10 1 middle-aged
• Higher incidence of autoimmune disease

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Clinical Course

• Euthyroid--- ? hypothyroid
• Moderate goiter
• Hashitoxicosis(hyperthyroidism) occasionally
• 5 - B cell lymphoma or rarely papillary
  carcinoma of thyroid

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THYROID 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)

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ADENOMA

• Always follicular adenoma
• No papillary adenoma of thyroid.
• Solitary encapsulated.
• No capsular invasion.
• Histology Follicles gt macro (colloid), micro
  (fetal), normal size (simple), trabecular
  (embryonal).
• Sometimes composed of Hürthl cells (oncocytic)?
  Hurthle cell adenoma.

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ADENOMA
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ADENOMA
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CARCINOMA OF THYROID

• Causes
• Ionizing radiation
• Hashimotos thyroiditis
• Graves disease?

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Papillary Carcinoma 60-70

• The most common type
• Young age 20-50y , FM31
• 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)

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• 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

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Papillary Carcinoma
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Follicular 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).

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Follicular Carcinoma

• Haematogenous spread (lung, bone, liver. . )
• Poorer in prognosis than papillary carcinoma.
• Represent approximatly 15
• Most patients are gt40y
• TYPES
  1- minimally invasive FC.
  2- widely
  invasive FC.
  

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Medullary Carcinoma of thyroid lt5

• 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

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Medullary Carcinoma
amyloid
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Medullary Carcinoma

• It has slow but progressive growth
• Both lymphatic and hematogenous metastasis
  occurs
• 10-20 are familial, multicenteric in young age,
  associated with MEN 23
• Immuno ve calcitonin
• 80-90 sporadic, solitary, old age

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Anablastic carcinoma 5-10

• 0ccurs in patient gt 60 y
• Poorly differentiated, highly malignant tumour
  usually forms bulky necrotic mass often
  disseminate extensively through blood
• death occurs within 1-2 years (lt10 survive for
  10y)
• Histological variants
• Giant cells, spindle cells(sarcomatoid), squamoid
  cells

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PARATHYROID GLAND

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PARATHYROID GLAND

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Hyperparathyroidism

• - 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 gt 40y

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Clinical features

• Asymptomatic (lethargyweakness)
• 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

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Parathyroid adenoma
adenoma
normal
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• Adenoma Hyperplasia
• In adenoma one gland, Hyperplasia gtone 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.

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Parathyroid carcinoma
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MULTIPLE ENDOCRINE NEOPLASIA

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MULTIPLE ENDOCRINE NEOPLASIA (MEN)

• MEN are syndromes characterized by
  hyperplasic or neoplastic involvement of at
  least two endocrine glands and sometimes
  associated with non-endocrine lesions.

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• MEN I Wermer s Syndrome
• Parathyroid adenom/hyperplasia .
• Pituitary adenoma .
• Pancreatic lesions (hyperplasia adenoma ,
  carcinoma )
• Mutant gene(MEN1) locus at 11q13
• Autosomal dominnant

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• 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

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• MEN III (IIb) William syndrome
• similar to MEN II plus
• Marfanoid bodily habitus
• Multiple mucocutanenous
  ganglioneuromas
• Parathyroid involvement (none/rare).