THYROID GLANDAbdelrahman Al-daqqa

Dr Abdul Jabbar Samar ,

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

CONTENTS:

Thyroid gland

Anatomy

Physiology

history

Examination

Tumors

Anatomy of Thyroid gland

Anatomy

Blood Supply

:Superior and inferior thyroid arteries

Venous drainage

Superior, middle and inferior thyroid veins

Nearby structures

Recurrent and external laryngeal nerves

Parathyroid glands Trachea / larynx Oesophagus / pharynx Carotid sheath

Physiology of Thyroid

TRH TSH T4,T3

Hyper vs Hypo

TSH T3,T4 Most common causes Clinical manifestations

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)

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.

ADENOMA

CARCINOMA OF THYROID

Causes:Ionizing radiationHashimoto’s thyroiditisGrave’s disease?

Papillary Carcinoma 60-70%

• The most common type• Young age 20-50y , F:M=3:1• Forming papillae and psammoma bodies

• 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

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).

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.

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

Medullary Carcinoma

amyloid

Medullary Carcinoma

It has slow but progressive growth Both lymphatic and hematogenous

metastasis occurs 10-20% are familial, multicenteric in

young age. Immuno: +ve calcitonin 80-90% sporadic, solitary, old age

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

Approach?

History (neck swelling)History (neck swelling)

-When was it first noticed? (appear )When was it first noticed? (appear )

- What made the patient notice the lump?What made the patient notice the lump?

- What are the symptoms of the swelling? (pain / discharge/ interfere with What are the symptoms of the swelling? (pain / discharge/ interfere with breathing/swallowing?)breathing/swallowing?)

- Has the swelling changed since it was first noticed? (bigger / smaller / fluctuate Has the swelling changed since it was first noticed? (bigger / smaller / fluctuate in size?)in size?)

- Does the swelling ever disappear? (on lying down / exercise?)Does the swelling ever disappear? (on lying down / exercise?)

- Has the patient ever had any other swelling? (in the past / concurrent?)Has the patient ever had any other swelling? (in the past / concurrent?)

- What does the patient think caused the swelling? (injury / systemic illness?)What does the patient think caused the swelling? (injury / systemic illness?)

Physical examinationPhysical examination

Examination of the head and neck is challenging in that much of the area to be examined is not easily visualized. Patience and practice are necessary to master the special instruments and techniques of examination

Physical examinationPhysical examination

- -InspectionInspection

- -PalpationPalpation

- -PercussionPercussion

- -AuscultationAuscultation

inspection

Site• Also, single vs. multiple.• Distance from a bony prominence landmark.

Size Shape Surrounds

• Remote surrounds first, then local surrounds.• Also, surrounding neurological or motor deficits.

Surface• Smooth vs. rough vs. indurated.• Skin, scars.

Edge• Clear vs. poorly defined.

Transillumination, if applicable.• Whether a torch behind lump will allow light to shine through.• Esp. used in testicular mass.

Palpation Temperature

• Feel with back of fingers on surface, surrounds. Tenderness

• Ask to tell when feel pain.• Nerve: can cause pins and needles.

Consistency• Soft, spongy, firm.

Mobility and attachment• Move lump in two directions, right-angled to each other. Then repeat exam when muscle contracted:• Bone: immobile.• Muscle: contraction reduces lump mobility.• Subcutaneous: skin can move over lump.• Skin: moves with skin.

Pulsatile• Assess with 2 fingers on mass:• Transmitted pulsation: both fingers pushed same direction.• Expansile: fingers diverge (esp for AAA).

Fluctuation [fluid-containing]• Assess by placing 2 fingers in "peace sign" on either edge of lump, then tapping lump center with index finger of other hand: fluctuant lump will displace peace sign fingers.• Very large masses can be assessed by a fluid thrill. See Ascites examination.

Irreducible• Compressible: mass decreases with pressure, but reappears immediately upon release.• Reducible: mass reappears only on cough, etc.

Percussion and auscultation

Percussion:• Dullness.• Resonance.

Auscultation:• Bruit.

11 . .CBC :-CBC :- ( infection , lymphoma ( infection , lymphoma ……..etc. )……..etc. ). .

33 . .TFT :-TFT :- ( Thyroid ) ( Thyroid ). .

44 . .PTH :-PTH :- ( Parathyroid ) ( Parathyroid )

55 . .Calcitonin . Thymoglobulin :- Calcitonin . Thymoglobulin :- ( Thyroid )( Thyroid ). .

66 . .Tuberculine test :-Tuberculine test :- ( T.B. ) ( T.B. ). .

77 . .CXR :-CXR :- ( Lung lesions ) ( Lung lesions ). .

..

•History •Physical exam. •Tests of thyroid function

a. TSH ( thyrotropine) single most sensitive test b. TT4 ( total thyroxine) c. FT4 ( free thyroxine) d. TT3 ( total triioddthyronine)

e. FT3•Ultrasound • Isotope scanning

Assessment of pts with thyroid disease

90% of nodules categorized as 1. benign group 65% 2. suspicious 15% 3. malignant 5% 4. nondiagnostic 15%

• Thyroglobulin levels • Serum calcitonin • CT. scan & MRI

•FNAC

Recurrent laryngeal nerve injury

Thank you!