Thyroid glands 12th

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

2. CONTENTS:
• Pituitary gland
– Hypopituitarism
– Hyperpituitarism
– Posteroir pituitary syndromes
• Thyroid galnd
– Hypothyrodism
– Hyperthyrodism
– Goiter
– Thyrodidtis
– Tumors
• Parathyroid glands
– Hyperparathyroidism
– Hypoparathyroidism

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

4. THYROID GLAND

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

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

8. Hypothyroidism:
• Causes:
– structural or functional
– 95% are due to:
• Surgical or radiation ablation
• Hashimoto’s thyroiditis
• Primary idiopathic hypothyroidism

9. Cretinism
• This is uncommon disease of
childhood due to failure of thyroid to
synthesize thyroid hormones 
hypothyroidism

10. Myxedma, cretenism

11. • Neurologic & myxedematous
patterns
• Clinically:
– mental retardation
– growth retardation (short stature)
– coarse facial features with dry skin and
protruding tongue
– muscle weakness and umbilical hernia

12. 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)

13. 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

14. •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

15. • 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

16. Thyrotoxicosis
Upper, thyrotoxicosis
Lower, after
treatment

17. Goiter
• Goiter simply means enlarged
thyroid

19. 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

20. 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

21. Solitary thyroid nodule
• Size (symptoms)
• Possible hyperfunction
• Usually colloid nodule >70%
• Adenoma 20-30%
• Carcinoma <5%
•  - Radioactive iodine (Hot & cold
nodule)
• FNA & biopsy
• Thyroid function

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

23. GRAVE’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

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

25. Morphology
• Gross:
diffuse
symmetrical
enlargement of
thyroid

26. THYROIDITIS
• Hashimoto’s thyroiditis
• Subacute
(granulomatous,DeQuervian)
thyroiditis
• Chronic lymphocytic (painless)
thyroiditis
• Riedel’s fibrous thyroiditis

27. Hashimoto’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.

28. Pathogenesis
• B cells  autoantibodies against
microsomes and thyroglobulin.
• Cell-mediated destruction of the
gland
• ♀ : ♂ = 10 : 1 middle-aged
• Higher incidence of autoimmune
disease

29. Clinical Course
• Euthyroid---  hypothyroid
• Moderate goiter
• Hashitoxicosis(hyperthyroidism)
occasionally
• 5% - B cell lymphoma or rarely
papillary carcinoma of thyroid

30. 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)

31. ADENOMA
• 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.

32. ADENOMA

33. ADENOMA

34. CARCINOMA OF
THYROID
• Causes:
– Ionizing radiation
– Hashimoto’s thyroiditis
– Grave’s disease?

35. Papillary Carcinoma
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)

36. •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

37. Papillary Carcinoma

38. 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).

39. Follicular 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.

40. Medullary Carcinoma of
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

41. Medullary Carcinoma
amyloid

42. 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 2&3
• Immuno: +ve calcitonin
• 80-90% sporadic, solitary, old age

43. 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

46. PARATHYROID GLAND

47. PARATHYROID GLAND

48. 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 > 40y

49. Clinical 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

50. Parathyroid adenoma
adenoma
normal

51. 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.

52. Parathyroid carcinoma

53. MULTIPLE ENDOCRINE
NEOPLASIA

54. 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.

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

56. • 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

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