Multi nodular goitre (MNG)

MULTI NODULAR

GOITREL AYA K P I L L A I

CONTENTS• ANATOMY AND PHYSIOLOGY OF THYROID • GOITRE• CLASSIFICATION OF GOITRE• MULTI NODULAR GOITRE• AETIOPATHOGENESIS• CLINICAL FEATURES• INVESTIGATIONS• TREATMENT• EXAMINATION OF THYROID SWELLING

GOITRE ??

Goitre from latin word ‘guttur’ meaning the throat

Goitre is generalised enlargement of thyroid gland

ANATOMY

PHYSIOLOGY

CLASSIFICATION OF THYROID SWELLINGSIMPLE GOITRE DIFFUSE HYPERPLASTIC PHYSIOLOGICAL PUBERTAL PREGNANCY MULTINODULAR GOITRE

TOXIC DIFFUSE(GRAVES DISEASE) MULTINODULAR TOXIC ADENOMA

NEOPLASTIC BENIGN MALIGNANT

INFLAMMATORY AUTOIMMUNE CHRONIC LYMPHOCYTIC THYROIDITIS HASHIMOTO’S DISEASE GRANULOMATOUS De QUERVAIN’S THYROIDITIS FIBROSING REIDEL’S THYROIDITIS INFECTIVE ACUTE CHRONIC

DIFFUSE HYPERPLASTIC GOITRE

MULTI NODULAR GOITRE

MNG • There are multiple nodules in thyroid• Progression from diffuse hyperplastic goiter• Can weigh upto 2kg• Mostly euthyroid• More common in FEMALES• They can be : NonToxic & Toxic

• Toxic MNG : a hyperfuntioning nodule may develop within a long standing goiter resulting in hyperthyroidism . The condition called PLUMMER SYNDROME

AETIOPATHOGENESIS• Puberty , pregnancy : demand feedback in TSH level hypertrophy of

gland ( physiological goiter)

• Endemic : iodine deficiency. daily requirement : 0.1-0.15 mg

• Dyshormonogenesis: familial ; autosomal recessive condition with deficiency of

peroxidase or dehalogenase resulting in sporadic goiters.

• Goitrogens : such as cabbage, drugs like sulfonamides , iodides

• Previous irradiation to neck

GOITROGENS• Environmental

– Cassava root (contains thiocyanate)– Vegetables cruciferae family (cabbage, cauliflower, brussel sprouts)– Milk from regions where goitrogens are present in grass– Others

• Drugs– Iodides– Amiodarone, aminoglutethemide, Lithium– Cobalt– Diiodoquinone– Ethionamide– PAS

ENDEMIC GOITRE AREAS

STAGES IN GOITER FORMATION

STIMULATION DIFFUSE HYPERPLASTIC GOITRE (reversible if stimulation ceases)

MIXED PATTERN with areas of active & inactive lobules (as a result of fluctuating stimulation)

Active lobules bcom more vascular & hyperplastic until hemorrhage occurs, causing central necrosis .

Necrotic lobules coalesce to form nodules filled either wih iodine free colloid or a mass of new but inactive follicles

Continual repetition of this process results in a nodular goitre

PATHOLOGY

• GROSS : multilobulated ; cut section has irregular nodule containing amts of gelatinous colloid. Regressive changes occur frequently in older lesion which include areas of hemorrhage, fibrosis, calcification, and cyst changes• MICROSCOPY : follicles of varying size. area of hemorrhage, hemosiderin-laden macrophages calcification

CLINICAL FEATURES

• Mass effects like dyspnea , dysphagia, hoarseness ,compression to the great vessels (superior vene cava syndrome).

• Cosmetic effects

• Mostly euthyroid , may present with hyperthyroidism (toxic MNG) • Hypothyroidic presentations in specific clinical settings.

INVESTIGATIONS• Thyroid function tests•Ultrasonography (USG)• Fine needle aspiration cytology (FNAC)•Complete blood picture (CBP)•X-ray neck :AP & Lateral view•CT scan : to look for retrosternal extension • Thyroid scan-contains radioactive I • Indirect laryngoscopy : to see vocal cord mobility

COMPLICATIONS• Dyspnoea / dysphagia• Secondary thyrotoxicosis • Calcification of nodules• Degeneration of nodules• Hemorrhage into nodules• Malignant transformation (follicular/papillary)- 5%• Cosmetic disfigurement

TREATMENT• In the early stages a hyperplastic goiter may regress if thyroxine

is given in a dose of 0.15-0.2 mg daily for few months.

• Although the nodular stage is irreversible , more than half of benign nodules will regress in size over years.

• Most of the MNG are asymptomatic and do not require operation.• Operation may be indicated on cosmetic grounds, for pressure

symptoms, or in response to patient anxiety.

• Retrosternal extension is an indication for thyroidectomy.

• When entire gland Is involved – total thyroidectomy is better

• Subtotal thyroidectomy is done depending on the amt of gland involved, location

8gms of thyroid tissue is retained in each lateral lobe

• often partial thyroidectomy or Harley dunhill operation (one lateral lobe + isthmus+ opp side subtotal or partial)

• Reoperation for recurrent nodular goiter is more difficult and hazardous and for this reason, total thyroidectomy is favoured in younger patients.

• Total lobectomy and total thyroidectomy have additional advantage of being therapeutic for incidental carcinomas.

• There is some evidence that radioactive iodine may reduce size of recurrent nodular goiter after previous subtotal resection and in some circumstances it is safer alternative than reoperation.

• Incision : a gently curved skin crease incision made between the notch of thyroid cartilage and suprasternal notch- KOCHERS

• Superior thyroid artery ligated Inferior thyroid artery are not routinely ligated to preserve Parathyroid blood supply.

POST OP COMPLICATIONS

•Bleeding• infection• Temporary\ permanent loss of voice• Temp\permanent hypocalcemia•Vocal cord paralysis•Need for life long thyroid supplements like L-thyroxine

PREVENTION

• Use of iodised salt • At puberty : 0.1 mg or 0.2 mg thyroxine• Reduce the use of goitrogens

EXAMINATION OF A THYROID SWELLING

• INSPECTION : by Pizillo’s method size, shape and location and borders, surface look for redness, scar, dialated vein pulsation, sinuses.

• Palpation : Lahey’s method for palpation of deep surface Crile’s method for small nodules measure size, shape, consistency, mobility kochers test for stridor berry’s sign for carotid pulse

• Percussion : Dull note if retrosternal extension

• Auscultation: bruit

Pizillo’s method

Crile’s method

Lahey’s method

Kocher’s test

PEMBERTON’S SIGN

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