pathology of the thyroid gland targon

7/27/2019 Pathology of the Thyroid Gland Targon

1/59

Pathology of the Thyroid Gland

Lt.col. R.TargonPhD medicine, professor

assistant


2/59

Diseases of the Thyroid Gland

Congenital diseases

Inflammation Functional abnormality

Diffuse and Multinodular goiters

Neoplasia


3/59

Anatomy

Intimate anatomical relationships

TG and recurrent laryngeal nerve TG and superior laryngeal nerve

TG and parathyroid glands


4/59

Embriology

Originates from foramen ceacum at the base of the tongue

and descends into the neck, anterior to the hyoid bone, in front of the trachea.

The tract left behind ( thyreoglossal tract) may persist and form a cyst

(thyreoglossal cyst)

The cyst may form a cutaneous fistula (thyreoglossal fistula)


5/59

Evaluation of Patients with Thyroid

Disease

Tests of Thyroid Function

Serum TSH

Total T4 and Total T3

Free T4 and Free T3

Thyroid Antibodies

Serum Thyroglobulin


6/59

Evaluation of Patients with Thyroid

Disease

Thyroid Imaging

Radionuclide Imaging (iodine-123 (123I) and iodine-131 (131I))

Ultrasound

CT/MRI Scan


7/59

Cases of midline swelling

Thyroid (patient with multinodular goitre)


8/59

Cases of midline swelling

Thyreoglossal cyst


9/59

Congenital Thyroid Diseases

Agenesis /Aplasia

Hypoplasia Accessory or aberrant thyroid glands

Thyroglossal duct cyst


10/59

Thyroglossal Duct Cyst

Children

Failure of regression Neck, medial

Squamous or columnar lining

Complications: inflammation, sinus tracts


11/59

Inflammation

Thyroiditis

Acute illness with pain

Infectious

Acute (Suppurative)

Chronic

Subacute or granulomatous (De Quervains)

Little inflammation with dysfunction

Subacute lymphocytic thyroiditis

Fibrous (Riedel) thyroiditis

Autoimmune

Hashimoto (lymphocytic) thyroiditis


12/59

HASHIMOTO THYROIDITIS

Most common cause of hypothyroidism

Autoimmune, non-Mendelian inheritance

45-65 years, F:M = 10-20:1

Painless symmetrical enlargement (minimally ormoderately enlarged firm gland)

20% of patients present with hypothyroidism, and 5%present with hyperthyroidism (hashitoxicosis).

Risk of developing B-cell non-Hodgkins lymphoma Other concomitant autoimmune diseases

Endocrine and non-endocrine


13/59

Hashimoto Thyroiditis

Pathogenesis

Immune systems reacts against a variety of thyroidantigens

Progressive depletion of thyroid epithelial cells which

are gradually replaced by mononuclear cells

fibrosis

Immune mechanisms may includes:

CD8+ cytotoxic T cell-mediated cell death

Cytokine-mediated cell death Binding of antithyroid antibodies antibody

dependent cell-mediated cytotoxicity


14/59


Diffuse enlargement

Firm or rubbery

Pale, yellow-tan, firm

& somewhat nodular

cut surface


15/59


Massivelymphoplasmcytic

infiltration with lymphoidfollicles formation

Destruction of thyroidfollicles

Remaining follicles are

small and many are linedby Hurthle cells

Increased interstitialconnective tissue


16/59

Riedel's ThyroiditisRiedel's struma or invasive fibrous

thyroiditis predominates in women between the ages of 30 and 60

years

replacement of all or part of the thyroid parenchyma by

fibrous tissue, which also invades into adjacent tissues

"woody" thyroid gland with fixation to surrounding tissues

associated with other focal sclerosing syndromes,

including mediastinal, retroperitoneal, periorbital, andretro-orbital fibrosis, and sclerosing cholangitis, suggesting

that it may in fact be a primary fibrotic disorder.


17/59

Functional Abnormality

Hyperfunction

in level of hormone toxic effects

Due to: Diffuse hyperplasia

Hyperfunctioning multinodular goiter

Hyperfunctioning adenoma

Subacute lymphocytic thyroiditis


18/59

Functional Abnormality

Hypofunction

in level of hormone impair development in infants

and slowing of physical and mental ability in adults

Due to:

Postablation

Surgery

Radiation

Autoimmune thyroiditis

Drugs

Dyshormonogenetic


19/59

Graves Disease

Most common cause of endogenous hyperthyroidism

Autoimmune disease with genetic susceptibility associated withHLA-B8 and DR3 Female:Male = 5:1 Peak incidence between the ages 40 and 60 years

Characterized by hyperthyroidism, symptoms of increased

adrenergic stimulation include palpitations, nervousness, fatigue,emotional lability, hyperkinesis, and tremors Diffuse enlargement with audible bruit Ophthalmopathy with exophthalmos: Wide,staring gaze (fixed look) Lid lag, (von Graefe's sign) Spasm of the upper eyelid revealing the sclera above the

corneoscleral limbus (Dalrymple's sign) Dermopathy (Pretibial myxedema) Gynecomastia levels of free T4 & T3and levels of TSH in blood uptake of radioactive iodine


20/59

Graves Disease

Ophthalmopathy with exophthalmos


21/59

Graves Disease

Ophthalmopathy with exophthalmos


22/59

Graves Disease

Dermopathy (Pretibial myxedema)


23/59

Graves Disease

Autoimmune disease with breakdown of helper-T-cell tolerance

Excessive production of TWO thyroid autoantibodies:

1) Thyroid-stimulating antibody (TSAb) &2) Growth-stimulating antibody (GSAb)

Antibodies bind to the TSH receptor of the follicular cell

Stimulation of the cell resulting in:

Increased levels of thyroid hormones &

Hyperplasia of the thyroid gland

Hyperthyroidism and Thyroid gland enlargement


24/59

Graves Disease

Symmetrical

enlargement of

thyroid gland

Cut-surface is

homogenous, soft and

appear meaty

Hyperplasia andhypertrophy of

follicular cells


25/59

Diffuse & Multinodular goiters

Latin gutteria, struma

Reflects impaired synthesis of thyroid hormone

most often caused by iodine deficiency

Impairment leads to compensatory in TSHlevels hypertrophy and hyperplasia of follicular

cells gross enlargement of gland

Euthyroid metabolic state

Degree of enlargement is proportional to level and

duration


26/59

Diffuse nontoxic goiter

Diffuse non-toxic (simple) goiter

colloid goiter

Endemic

sporadic (dyshormonogenetic)


27/59

Endemic Goiter

Low iodine content in drinking water & food(Himalayas, Alps, Andes, areas far from the

sea) Prevalence decreasing due to prophylactic

iodination of salt

Iodine deficiency causes decreased hormonelevels & consequent elevation in TSH


28/59

Sporadic Goiter

Commonest type of goiter

Euthyroid, but may be hypo- or hyper-

Mostly idiopathic, but RARELY, may be causedby:

Drugs used in Rx of hyperthyroidism

Goitrogens e.g. cauliflower, cabbage, cassava

Suboptimal iodine intake

Hereditary enzymatic defects


29/59

Multinodular goiter Recurrent episodes of hyperplasia and involution

leads to irregular enlargement

All long standing diffuse endemic and sporadic goitermay eventually convert to multinodular goiter

Causes most extreme enlargement and may bemistaken for neoplasm

May arise due to variable response of follicular cellsto external stimuli such as trophic hormones

With uneven follicular hyperplasia, generation ofnew follicles and uneven accumulation of colloid rupture of follicle and vessels hemorrhage, scarring& calcification nodularity


30/59

Multinodular Goiter

Asymmetric

enlargement

Multinodular

Haemorrhage

Calcification

Fibrosis

Cystic degeneration


31/59

Multinodular Goiter


32/59

Multinodular Goiter

Numerous follicles

varying in size

Recent haemorrhage

Haemosiderin

Calcification

Cystic degeneration

+/- dominant nodule


33/59

Multinodular Goiter


34/59

Multinodular Goiter


35/59

Toxic Multinodular Goiter

Toxic multinodular goiters usually occur in

individuals older than 50 years of age

Symptoms and signs of hyperthyroidism aresimilar to Graves' disease

Extrathyroidal manifestations are absent


36/59

Thyroid Neoplasms

I. Primary Tumours

Epithelial

Malignant Lymphomas Mesenchymal tumours

II. Metastatic Tumours


37/59

Epithelial Thyroid Neoplasms

Tumours of follicular cells

Benign (adenomas)

Follicular adenoma

Malignant (carcinomas)

Follicular carcinoma (10-20%)

Papillary carcinoma (75-85%)

Undifferentiated (anaplastic) carcinoma (


38/59

Follicular Adenoma

Benign, encapsulated tumor showing evidence

of follicular differentiation

Common

Predominantly young to middle women

Presents as solitary thyroid nodule Painless nodular mass, cold on isotopic scan


39/59

Follicular Adenoma

Solitary, Variably sized,

encapsulated, well-

circumscribed with

homogenous gray-white to red-brown

cut-surface

+/- degenerativechanges


40/59

Plummer's Disease (Toxic

Adenoma)

Hyperthyroidism from a single

hyperfunctioning nodule

Physical examination usually reveals a

solitary thyroid nodule without palpablethyroid tissue on the contralateral side

RAI scanning shows a "hot" nodule with

suppression of the rest of the thyroid

gland.

Rarely malignant


41/59

Follicular Carcinoma

Second most common form, 10-20%

Females > Males, average age ~ 45 - 55 yr

Rare in children

Solitary nodule, painless, cold on isotopic scan

Widely invasive Vs minimaly invasive

50% 10 yr survival Vs 90%10 yr survival

Haematogenous route is preferred mode of spread


42/59

Follicular Carcinoma

Solitary round or oval

nodule

Thick capsule

Composed of follicles

Capsular invasion or

vascular invasion

within our outsidecapsular wall


43/59

Papillary Carcinoma

Commonest thyroid malignancy, 75-85%

Female:Male = 2.5:1

Mean age at onset = 20 - 40 yr

May affect children

Prior head & neck radiation exposure

Indolent, slow-growing painless mass cold onisotopic scan

Cervical lymphadenopathy may be presentingfeature


44/59

Papillary Carcinoma

Variable size

(microscopic to

several cm)

Solid or cystic

Infiltrative or

encapsulated

Solitary ormulticentric (20%)


45/59

Papillary Carcinoma

Papillae or follicles

Psammoma bodies

NUCLEAR

FEATURES***


46/59

Papillary Carcinoma

Nuclear Features

Optically clear (ground

glass, Orphan Annie)

nuclei

Nuclear

pseudoinclusions or

nuclear grooves


47/59

Papillary Carcinoma

Prognosis

Excellent but following factors play importantrole:

Age and sex

Size

Multicentricity

Extra-thyroid extension

Distant metastasis

Total encapsulation, pushing margin of growth &cystic change


48/59

Anaplastic Carcinoma

Rare; < 5% of thyroid carcinomas

Highly malignant and generally fatal < 1yr.

Elderly 65 yrs; females slightly > males

Rapidly enlarging bulky neck mass

Dysphagia, dyspnoea, hoarseness


49/59


Large, firm, necrotic mass

Frequently replaces entire thyroid gland

Extends into adjacent soft tissue, trachea andoesophagus

Highly anaplastic cell on histology with:

Giant, spindle,small or mix cell population

Foci of papillary or follicular differentiation


50/59


Cellular pleomorphism

+/- multinucleated

giant cells

High mitotic activity

Necrosis


51/59

Medullary Thyroid Carcinoma (MTC)

Malignant tumour of thyroid C cells producing

cacitonin

5 % of all thyroid malignancies

Sporadic (80%)

Rest in the setting of MEN IIA or B or asfamilial without associated MEN syndrome


52/59


Sporadic MTC

Middle-aged adults

Female:male = 1.3:1

Unilateral involvement of gland

+/- cervical lymph node metastases

Indolent course with 60-70% 5-yr survival after

thyroidectomy

l i l d i l i &


53/59

Multiple Endocrine Neoplasia Types IIA &

IIB

Germ-line mutation in Retprotooncogene on

chromosome 10q11.2

MEN IIA: MTC, phaeochromocytoma, parathyroidadenoma or hyperplasia

MEN IIB: MTC, phaeochromocytoma, mucosalganglioneuromas, Marfanoid habitus, other skeletal

abnormalities


54/59


Associated with MEN IIA

Younger patients in twenties

Multicentric and bilateral

Slow growing

Associated with MEN IIB

Even younger patientsin teens

Aggressive with early metastasis

Poor prognosis


55/59


Histology same forsporadic & familial

Solid, lobular or

insular growthpatterns

Tumour cells round,polygonal or spindle-

shaped Amyloid deposits in

many cases


56/59


Amyloid deposits stain

orange-red with

Congo Red stain


57/59

Prognosis of Thyroid Carcinomas

Papillary Best prognosis

Follicular

Medullary

Anaplastic Worst prognosis


58/59

Secondary Tumours

Direct extensions from: larynx, pharynx,

oesophagus etc.

Metastasis from:

renal cell carcinoma, large intestinal

carcinoma, malignant melanoma, lung

carcinoma, breast carcinoma etc.


59/59

Solitary thyroid nodule

Papillary carcinoma

Follicular carcinoma

Medullary carcinoma

Follicular adenoma

Hyperplastic (dominant) nodule

Metastatic neoplasms FINE NEEDLE ASPIRATION CYTOLOGY

pathology of the thyroid gland targon

Documents