SIMPLE GOITRE&THYROIDITIS

SIMPLE GOITRE Other names:-

Diffuse non-toxic Colloid Juvenile (teenagers)

Characteristics:- Soft, symmetrical, diffuse NO nodularity, tenderness, bruit, LNE TFT normal NO anti-thyroid Ab

SIMPLE GOITRE Age group:-

15-25 years most common

Causes:- Pregnancy Puberty Iodine deficiency Goitrogen intake – Cabbage, cauliflower Inherited thyroid hormone dysgenesis:-

Iodine transport, thyroglob synthesis, organification, coupling, iodide regeneration

SIMPLE GOITRE Clinical features:-

Asymptomatic mainly Noticed by others, self Cosmetic concern

Localised pain & swelling (Spont bleed) Large goitre -

Tracheal compression Esophageal compression

SIMPLE GOITRE Examination:-

Diffuse, symmetrical enlargement Soft, nontender NO nodules, LNE Pemberton’s sign – raise arms, then

Facial congestion Faintness Ext jugular vein compression Substernal goitre

SIMPLE GOITRE Investigations:-

TFT – r/o hypo/hyper Normal Normal T3 & TSH, low T4 (Iod def, more T4→T3) Anti-TPO Ab – r/o autoimmune thyroid disease Urinary Iodine - <10 mcg/dL = Iodine def USG – If nodularity suspected

SIMPLE GOITRE Treatment:-

Juvenile/ pregnancy – TFT normal, NO Rx. Usually regress spontaneously

Iodine deficiency – Iodine Thyroxine

Surgery – Tracheal compression Thoracic outlet obstruction Cosmetic

Radioiodine – Follow-up for hypothyroidism

SIMPLE GOITRE Recurrent episodes –

Fibrosis Nodule formation - MNG Autonomous function – toxic nodule

THYROIDITIS

CAUSES Acute

Bacterial infection: Staphylococcus, Streptococcus, and Enterobacter

Fungal infection: Aspergillus, Candida, Coccidioides, Histoplasma, and Pneumocystis

Radiation thyroiditis after 131I treatment Amiodarone (may also be subacute or chronic)

Subacute Viral (or granulomatous) thyroiditis Silent thyroiditis (including postpartum thyroiditis) Mycobacterial infection

Chronic Autoimmunity: focal thyroiditis, Hashimoto's thyroiditis, atrophic

thyroiditis Riedel's thyroiditis Parasitic thyroiditis:

Echinococcosis, strongyloidiasis, cysticercosis Traumatic: after palpation

SUPPURATIVE THYROIDITIS Rare Suppuration –

Bacterial Fungal

Associated – Pyriform sinus (4th brachial pouch) Long standing goitre Degeneration of malignancy

SUPPURATIVE THYROIDITIS Clinical

Thyroid pain – ref to throat, ear Fever, dysphagia Erythema over thyroid Small, tender, asymmetric goitre

Differentials Thyroiditis – subacute, chronic Haemorrhage into cyst Malignancy Amiodarone induced thyroiditis Amyloidosis

SUPPURATIVE THYROIDITIS Investig –

TC & ESR ↑ FNAC – polymorph infiltration Specimen gram stain, C&S CT, USG – abscess

Treatment – Antibiotics, antifungals Surgery –

Abscess Compressive symptoms (trachea, esophagus,

jugular veins)

SUPPURATIVE THYROIDITIS Complications –

Tracheal compression Retropharyngeal abscess Esophageal compression Septicaemia Mediastinitis Jugular vein thrombosis

DRUG INDUCED Interferons –

IFN-α IL-2

Amiodarone Can result in –

Painless thyroiditis Grave’s Hypothyroidism

Risk factor – Anti-TPO Ab+ve before Rx

AMIODARONE INDUCED Acute, subacute, chronic Class III antiarrhythmic Structure related = thyroid hormone 39% Iodine (wt) Stored in adipose (>6 mths for levels ↓) Actions –

↓ T4 release Inhibit deiodinase Weak thyroid hormone antagonist

AMIODARONE INDUCED Effects –

A/c transient ↓ thyroid function Persistent hypothyroid (women, anti-TPO Ab) Thyrotoxic (incipient Grave’s, MNG, Jod-

Basedow)

TFT – Initial T4 ↓ Then T4 ↑, T3 ↓ & thyroid effect ↓

Wolff-Chaikoff escape, deiodinase inhib, thyroxine inhib TSH initial ↑ , then N/↓

AMIODARONE INDUCED - Rx Hypothyroid – Levothyroxine Hyperthyroid – complex

Stop drug (often impractical) Type I –

Preclinical Grave’s, MNG Anti-thyroid high dose

Type II – Destructive thyroiditis Iodinated oral contrast (↓formation, conversion,

action) Glucocorticoid Lithium Near-total thyroidectomy

SUBACUTE THYROIDITIS Synonyms –

de Quervain’s Granulomatous Viral (lots of viruses)

Mimic pharyngitis

30-50 years, women:men = 3:1

SUBACUTE THYROIDITIS Pathophysiology –

Patchy inflammatory infiltrate Multinucleate giant cells Granuloma, fibrosis Disrupt + destroy thyroid follicles

Stages – 1 = Destruction (Tg,T3,T4 release.

Hyperthyroidism) 2 = Depletion (T3,T4 fall. Hypothyroidism) 3 = Recovery (TFT slowly returns to normal)

SUBACUTE THYROIDITIS Clinical –

Painful, symmetric goitre (ref to jaw, ear) Fever +/-, malaise Thyrotoxicosis URTI o/e Exquisitely tender goitre

Uncommon – Permanent hypothyroidism

Rare – Prolonged course with multiple relapses

SUBACUTE THYROIDITIS Investigations –

TFT – 1 = T3 & T4 ↑↑, TSH ↓↓ 2 = T3 & T4 ↓↓, TSH ↑↑ 3 = TFT normal

ESR ↑ TC ↑/N

SUBACUTE THYROIDITIS Treatment –

Aspirin – 600mg 4-6 hrly NSAIDs Glucocorticoid –

Severe local/systemic symptoms Taper 6-8 weeks

β-blocker – hyperthyroidism Levothyroxine – hypothyroidism (low dose) TFT 2-4 weekly (hyper, hypo, normo)

SUBACUTE THYROIDITIS Silent thyroiditis –

Synonyms – painless, postpartum 3 stages – hyper, hypo, normo Recovery norm Assoc – TPO +ve, type 1 DM ESR normal Severe thyrotoxicosis – propranolol Hypothyroidism – levothyroxine TFT annually – monitor for hypothyroidism

AUTOIMMUNE THYROIDITIS Focal –

Seen on autopsy Asymptomatic

Hashimoto’s – Lymphocytic infiltration Large, irregular, painless goitre

Atrophic – More fibrosis Less lymphocytic infiltrate Distorted architecture

AUTOIMMUNE THYROIDITIS Main mechanism –

T-lymphocytic injury Clinical –

Goitre – Hashimoto’s Hypothyroidism – atrophic, late Hashimoto’s Children –

Rare Slow growth, delayed facial development

AUTOIMMUNE THYROIDITIS Investigations –

TFT – Clinical/subclinical hypothyroidism

Anti-TPO Ab marker FNAC –

Lymphocytic infiltrate (Hashimoto’s) More fibrosis (atrophic)

USG – Heterogenous enlargement (Hashimoto’s) Atrophied gland (atrophic) No nodules

AUTOIMMUNE THYROIDITIS Treatment –

Monitor TFT regularly Levothyroxine if hypothyroid

REIDEL’S THYROIDITIS Rare Middle-aged women Pathophysiology –

Dense fibrosis Normal architecture lost Gland size enlargement Dysfunction uncommon

REIDEL’S THYROIDITIS Clinical –

Insidious, painless, hard, nontender goitre Compression –

Esophagus Trachea Neck veins Recurrent laryngeal nerves

Associated idiopathic fibrosis – Retroperitoneal, biliary tree Mediastinal, lung Orbit

REIDEL’S THYROIDITIS Diagnosis –

Open biopsy

Treatment – Surgical decompression Thyroxine if hypothyroid Tamoxifen (no evidence)