THYROID SWELLING

Question 1

DOMINANT SWELLING

Answer 1

Discrete swelling with evidence of abnormality elsewhere in the gland

Question 2

classify thyroid swelling

Answer 2

SIMPLE GOITRE(EUTHYROID)
1.diffuse hyperplastic (physiological , pubertal , pregnancy)
2. multinodular goitre

TOXIC
1. diffuse (graves disease)
2. multinodular
3. toxic adenoma

NEOPLASTIC
1. benign
2. malignant

INFLAMMATORY
1. autoimmune (hashimoto , c/c lymphocytic thyroiditis)
2. granulomatous(de Quervains)
3. fiibrosing (riedel’s)
4.infective (acute , chronic)
5. other (amyloid)

Question 3

chronic infections of thyroid

Answer 3

TB , Syphilis

Question 4

stimulus to thyroid follicles

Answer 4

TSH , Immunoglobulins

Question 5

Stages in goitre formation

Answer 5

• persistent growth stimulation - diffuse hyperplasia
  *later fluctuating stimulation - mixed pattern of areas of active and inactive lobules
  *active lobules become more vasular and hyperplastic until hmg and necrosis occur
  *necrotic lobules coalasce to form nodules
• most nodules are inactive and active nodules are present only in internodular tissue

Question 6

why goitre more common in females

Answer 6

owing to the presence of estrogen receptors in thyroid tissue

Question 7

GOITROGENS

Answer 7

Brassica vegetables - cabbage , kale , rape (contains thiocyanates)
calcium
iodine deficiency
iodide excess(inhibits organic binding of iodine)
drugs (PAS , anti thyroid drugs)
thiocyanates , perchlorates (interfere with iodide trapping)
thiouracil , carbimazole (interfere with oxidation of iodide)

Question 8

indications for surgery in simple goitres

Answer 8

underlying malignancy
pressure symptoms
cosmetic reasons

Question 9

Dunhill procedure

Answer 9

aka near total thyroidectomy
total lobectomy with subtotal resection of contralateral lobe

Question 10

solitary nodule thyroid

Answer 10

a discrete swelling in an otherwise impalpable gland
15% are malignant

Question 11

modality of choice to see tracheal compression and deviation

Answer 11

CT

Question 12

INDICATION FOR SURGERY IN SNT

Answer 12

RISK OF MALIGNANCY - FOLLICULAR ADENOMAS & PROVEN MALIGNANCIES

Question 13

POINTS FAVOURING HIGH RISK OF MALIGNANCY

Answer 13

Hard with irregular borders
fixity
RLN palsy is almost pathagnomic
lymphadenopathy with IJV involvement is almost diagnostic
recurrent cysts
discrete swelling in a male
either end of age range

Question 14

lifelong risk of recurrence and thyroid failure in subtotal resections

Answer 14

5%
upto 100% at 30 years

Question 15

graves disease pathology

Answer 15

hypertrophy and hyperplasia due to abnormal TSH-RAb that binds to tsh receptor sites
highly vascukar
diffuse toxic goitre appearing the same time as hyperthyroidism
primary thyrotoxicosis
frequently associated with eye signs
55% have family h/o autoimmune endocrine diseases

Question 16

toxic nodular goitre pathophysiology

Answer 16

secondary thyrotoxicosis
goitre is present long time before hyperthyroidism
usually the internodular tissue is the one that is overactive

Question 17

histology in hyperthyroidism

Answer 17

normally acini lined by flattened cuboidal epithelium
in thyrotoxicosis , there is hyperplasia of acini, which are lined by high columnar epithelium , many are empty or with vacuolated colloid in scalloped pattern

Question 18

thyrotoxicosis treatment

Answer 18

rest
sedation
antithyroid drugs (failure rate :55%)
surgery(rapid cure)
radioiodine(destroys thyroid cells)

Question 19

disadvantages of radioiodine

Answer 19

isotope facilities must be available
patient must be quarantined while radiation levels are high
avoid pregnancy
avoid close physical contact especially with children
eye signs may aggravate

Question 20

carbimazole block and replace regimen

Answer 20

doc
started 30-40 mg/day
once euthyroid - 5mh 8H with
maintenance dose of 0.1 mg thyroxine

last dose of carbimazole given the evening prior to surgery

Question 21

thyroid storm treatment

Answer 21

iv fluids ,ice packs , oxygen ,sedation
diuretics for cardiac failure
digoxin for atrial fibrillation
iv hydrocortisone

carbimazole 10-20 mg Q6H
sodium iodide 1 g iv or lugols iodine 10 drops by mouth Q8H
proprano;o; 1mg iv or 40 mg Q6H

Question 22

CLASSIFY THYROID NEOPLASM

Answer 22

BENIGN - Follicular adenoma
MALIGNANT –
PRIMARY
1. follicular epithelium - differentiated - follicuar(10%) , papillary(80%)
2. follicular poorly differentiated - anaplastic(5%)
3. parafollicular cells - medullary ca(2.5%)
4. lymphoid cells(2.5%)

 SECONDARY 1. Metastatic 2. local infiltrates

Question 23

oncogene in PTC

Answer 23

ret PTC3 - very aggressive short latency PTC
ret PTC1 - less aggressive

Question 24

de quervains thyroiditis ? management ?

Answer 24

fever , malaise , irregulr firm tender swelling
T4 high normal
I123 uptake low

prednisolone 20-30 mg daily for 7 days and then gradually taper over 1 month

Question 25

riedels thyroiditis

Answer 25

thyroid tissue is replaced by cellular fibrous tissue , which infiltrates through the capsule to muscles and adjacent organs
very hard and fixed

Question 26

riedels thyroiditis treatment

Answer 26

high dose steroids
tamoxifen
thyroxine replacement

Question 27

why diarrhea in medullary ca thryoid

Answer 27

5 hydroxytryptamine and prostaglandin release by tumour

Question 28

mdullary ca thyroid marker

Answer 28

arises from parafollicular c cells, derived from neural crest cells
CEA , calcitonin
thhey are not TSH dependeny and hence do not uptake I 123

Question 29

RADIOIODINE REFRACTORY DOSEASE

Answer 29

with advancing age and particularly if the disease is multiply recurrent , the tumour will lose iodine avidity
they can be considered for external beam radiotherapy

Question 30

threos

Answer 30

greek - shield

Question 31

father of modern thyroid surgery

Answer 31

theodor kocher