Management Of Thyroid Disorders

MANAGEMENT THYROID DISORDERS. Dr. L.D Lugaria • • • • • • •

Introduction Goitre Thyrotoxic Goitre. Solitary Thyroid nodule. Hyperthyroidism. Toxic Multinodular Goitre. Malignant Thyroid Tumours.

MANAGEMENT OF THYROID DISORDERS- Introd • Background knowledge- Anatomy, physiology, biochemistry of the thyroid gland. • Thyroid Disorders : Congenital or Acquired –Congenital :Atresia, incomplete descent/ectopic, Enzyme deficiency. -Acquired : .Infections-(bacterial, T.B, Viral) .Tumours –(Benign or Malignant). .Autoimmune (Circulating immunoglobulin)

ANATOMY • Position (5th -7th cervical vertebrae ant. Neck) • Relations and related important structures (Trachea, esophagus, carotids, sup/inf. laryngeal nerves, parathyroid glands). • Layers- (skin to gland) • Size • Blood supply-Arterial (sup./inf. Thyroid). -Venous (sup. Inf. Mid thyroid).

MANAGEMENT • History- symptoms: pain, ant. Neck swelling, Metabolic derangement, obstructive. • P.E- Signs: Mass anterior neck, Metabolic. • INVEST. –TFTs (T3, T4, TSH) ,U/S, AITI, X-ray, U/S, FNA, Biopsy, Radioisotope studies. • Treatment- Medical or surgical or combined

GOITRE • Goitre defn.- thyroid gland enlargement. • Goitre –physiological (puberty, pregnancy) - pathological (toxic or nontoxic). • Incidence varies: regions, F>M. • Goitre- endemic, sporadic, drug reaction • Variations- size, shape, consistency. • Clinical Features: asymptomatic/ symptomatic. • Symptomatic-compression (trachea, esophagus), Bleeding • INVEST: T3,T4,TSH. • Treatment (symptomatic/cosmesis)- subtotal thyroidectomy.

THYROTOXIC GOITRE Def.- Diffuse enlargement of the thyroid gland, T3&T4 raised. Causes- High TSH or TSH like proteins THYROIDITIS: Sub acute, Autoimmune or Riedel’s • Sub acute (De Quervan's disease)-rare - A flue like illness, with diffuse painful gland swelling. -Thyroid Abs may be raised. --Due to viral infection. –-Usually resolves.

THYROTOXIC GOITRE… •

Autoimmune Thyroiditis (Hashimoto’s disease). –Thyroid follicles destroyed by immunocompetent lymphocytes. –Serum Abs: against thyroglobulin, thyroid cell cytosol, and microsomes. – Histology: Marked lymphocytic infiltration around the destroyed follicles –Patient usually euthyroid, occ. thyrotoxic, longterm hypothyroid. –Most common in postmenopausal females (F:M=10:1). - Thyroid gland diffusely enlarged & firm. (Ddx mult. Goitre). –diagnosis: High circ antithyroid Abs, Histology. –Long standing : can transform to lymphoma. –Treatment: Small goitre thyroxin; Large & symptomatic-subt. Thyroidectomy (difficult).

THYROTOXIC GOITRE… • Riedel’s thyroiditis. –Very rare. –Thyroid tissue replaced by fibrous tissue (firm painless mass tracheal compression). • Treatment: -Sub acute –Resolves. -Autoimmune Thyroiditis- subtotal thyroidectomy (difficult and risky due to adhesions). –Riedel’s- surgical decompression.

SOLITARY THYROID NODULES • Defn: Painless solitary thyroid nodule. -50% are conspicuous palpable nodule in a multinodular gland. -50% true solitary nodule (50% benign adenomas & 50% cyst or cancer) • INVEST: FNA, U/S, TFTs (T3 T4 TSH), Isotope scan (hot, cool or cold). • TREATMENT: -Cysts-Aspiration (material for cytology) –Adenoma- Thyroidectomy. –Carcinoma (Follicular, medullary, lymphoma)Surgery.

HYPERTHYROIDISM • Due to elevated T3,T4. • Causes: -Pr. Thyrotoxicosis (Graves dx)-75%. –Toxic multinodular goitre. –Toxic adenoma.

PRIMARY THYROTOXICOSIS. • Autoimmune-TSH receptors in the thyroid gland stimulated by circulating immunoglobulins (TSI). • Gland uniformly hyperactive, very vascular and usually symmetrically enlarged. • Histology: Epithelial proliferation with papillary projections into follicles devoid of colloid. • TSI cross placental barrier causing IU/neonatal thyrotoxicosis.

PRIMARY THYROTOXICOSIS.. • CLINICAL FEATURES: -Usually young female (f : m=8:1) -FH –Moderately, uniform diffuse gland enlargement. -High circulating TSI, T3, T4 and low TSH. –Metabolic: Feeling hot at rest and heat intolerance; warm moist skin and weight loss but high appetite. – Increased sympathetic activity Tachycardia, palpitations, arrhythmias (AF), fine hand tremors, retracted upper eyelid, diorrhoea, anxiety. –Other features: Exophthalmos, pretibial myxoedema, prox.muscle myopathy, finger clubbing, menstrual irregularity.

PRIMARY THYROTOXICOSIS.. • DIAGNOSIS: -History. –PE –INVEST.-T3,T4, TSH • TREATMENT. –Antithyroid drugs which block iodine incorporation into tyrosine preventing T3&T4 synthesis. –Carbimazole 30-60mg/d (4divided doses) 4-6 wks; 515mg/d 12-18m. (Relapse 60-70% in 2yrs –Radioactive Iodine + Thyroxine replacement therapy. –Surgery: Subtotal thyroidectomy (70% cure rate &2025% recurrence).

TOXIC MULTINODULAR GOITRE& TOXIC ADENOMA • •

25% of thyrotoxicosis are multinodular (single nodule 1-2% pts). Usually follows longstanding nontoxic goitre with 1+ nodules becoming hyperactive. • Single adenoma secretes thyroid hormones autonomously & TSH completely suppressed. • Clinical features: - T.mult. Goitre commoner in elderly females. –Cardiac complications & exophthalmos rare. • Diagnosis: Isotope scan -Mult. -Isotope scans for increased uptake area(s). -Toxic adenoma- Hot nodule with the rest of the gland “silent”. •

Treatment: -Multinodular.-subt. Thyroidectomy. -Toxic adenoma- Lobectomy.

MALIGNANT THYROID TUMOURS. • Malignant tumours: -F:M =3:1 –Three main types: Papllary(50%), Follicular (1025%),Anaplastic (25-40%). Others: Medullary & lymphomas. • Papillary Carcinoma: -Rare after 40yrs. –Slow growing solitary thyroid lump –Enlarged palp. LNs –Histology :Complex papillary folds lined by several layers of cuboidal cells projecting into cystic spaces. –Teatment :Total/Near total Thyroidectomy + LN removal ; Hormone therapy (T3 20 qid); TSH monitoring. -Prognosis: Excellent -90% survival at 10yrs.

MALIGNANT THYROID TUMOURS… • Follicular Carcinoma: -Usually solitary thyroid nodule in 30-50yrs. –Common haematogenous spread (20% pts have mets in lungs, bone or liver). LN spread rare. –Histology: Malignant cells arranged in solid masses with rudimentary acini. –Treatment: Ttl thyroidectomy with preservation of the parathyroids and removal of all palp. LNs. –Post op. radioisotope scan (+vetherapeutic doses of radio iodine. –T3 for replacement &suppression of TSH secretion. Monitoring for rec. (-thyroglobulin). -Outcome:10yr survival=50%

MALIGNANT THYROID TUMOURS … • Anaplastic Carcinoma:

-Rapidly growing, highly

malignant. -Commoner in elderly pts. -Local invasion causes hoarseness (RLN), compression symptoms (dyspnoea, stridor, dysphagia). Cervical sympathetic involv. (Horner’s syndrome= pupillary contraction, enophthalmos, narrow palp. fissure, loss of sweating in head & neck). -Pulm. Mets common. –Treatment : Surg. To relieve symptoms; DXT/Chemo of marginal value. –Prognosis-poor (70% die 1yrof diagnosis