12. 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
13. 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
14. 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
17. 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
18.
19. 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
20.
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24.
25. 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.
26.
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33.
34. 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
35.
36. COMPLICATIONS
• Dyspnoea / dysphagia
• Secondary thyrotoxicosis
• Calcification of nodules
• Degeneration of nodules
• Hemorrhage into nodules
• Malignant transformation (follicular/papillary)- 5%
• Cosmetic disfigurement
37. 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.
38. • 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.
39. • 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.
40. POST OP COMPLICATIONS
• Bleeding
• infection
• Temporary permanent loss of voice
• Temppermanent hypocalcemia
• Vocal cord paralysis
• Need for life long thyroid supplements like L-thyroxine
41. PREVENTION
• Use of iodised salt
• At puberty : 0.1 mg or 0.2 mg thyroxine
• Reduce the use of goitrogens
42.
43. 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