Histology and pathology - thyroid

Question 1

what causes the thyroid enlargment with Graves’ disease

Answer 1

TSI stimulation

Question 2

what is the difference in histology between inactive and active thyroid follicles

Answer 2

inactive - low cuboidal cells. Follicle filled with colloid active - tall cuboidal to columnar cells. Scalloping of the colloid

Question 3

what is a simple goitre due to

Answer 3

impaired synthesis of thyroid hormone

Question 4

why are patients with a simple goitre usually end up euthryoid

Answer 4

because an increase in TRH will lead to enlargement of the thyroid follicles so they can produce more T3 and T4 –> then positive feedback stops -> normal TRH and T3 and T4

Question 5

what is the difference between endemic and sporadic goitre

Answer 5

endemic goitre - usually due to iodine deficiency (>10% of the population) sporadic goitre - due to congential biosynthetic defects, goitrogens etc

Question 6

what do you see histologically with sporadic goitre

Answer 6

• hyperplastic follicles of various sizes - follicles lined by hyperplastic, crowded cells - abundant colloid

Question 7

what causes and what happens with multinodular goitre

Answer 7

persistence of high TSH –> cycles of hyperplasia and involution –> large nodules, while others thyroid follicles rupture or haemorrhage and fibrose

Question 8

what is multinodular goitre

Answer 8

when the follicles undergo repeated cycles of hypertrophy and involution and some of the follicles eventually rupture and fibrose to make nodules

Question 9

What is the Pemberton’s sign

Answer 9

compression of the SVC when lifting your arms due to a goitre –> venous compression –> red face

Question 10

histology of a thyroid with Hashimoto’s thyroiditis

Answer 10

• mononuclear inflammatory infiltrate (lymphocytes, plasma cells, germinal centres) - Hurthle cells - abundant, eosinophilic, granular cytoplasm - increased interstitial connective tissue –> fibrosis

Question 11

gross pathology of Hashimoto’s disease

Answer 11

firm, tan yellow/pale colour, with nodules

Question 12

What causes hasimotos thyroiditis

Answer 12

breakdown of the bodies tolerance to thyroid tissues - CD8 cytotoxic cell mediated cell death - cytokine mediated cell death (IFN-gamma, Fas) - TSH-blocking antibodies

Question 13

risk factors for Hashimoto’s disease

Answer 13

female age (45-65) genetics

Question 14

which type of cancer does Hashimoto’s disease predispose you to

Answer 14

B-cell non-Hodgkin lymphoma

Question 15

What do you see clinically in results that tells you its Hashimoto’s thyroiditis

Answer 15

high TSH low free T4 high throglobulin antibodies very high anti thyroid peroxidase antibodies

Question 16

triad of clinical findings in a patient with Graves’ disease

Answer 16

hyperthyroidism infiltrative opthalmopathy pretibial myxoedema - in some patients

Question 17

what are the antibodies against with Grave’s disease

Answer 17

The TSH receptor

Question 18

what is the histology of someone with Grave’s disease

Answer 18

• follicular cells are tall and more crowded - diffuse hypertrophy and hyperplasia - may form papillae in the follicle lumen - widespread scalloping of colloid - lymphocytic infiltration (no fibrosis)

Question 19

risk factors for Grave’s disease

Answer 19

female age (20-50) genetics smoking

Question 20

what clinical results suggest Grave’s disease

Answer 20

low TSH high free T4 anti thryoid peroxidase antibodies high thyroid stimulating immunoglobin antibodies

Question 21

what cell, and how… does opthalmopathy occur in Grave’s disease

Answer 21

Fibroblasts - Express TSH-like antigens - produce more hyaluronic acid - transform into adipocytes

Question 22

what type of hypersenstivity are Grave’s disease and Hashimotos disease

Answer 22

Graves = Type II Hashimotos = Type IV