Thyroid

Question 1

Graves’ disease triad

Answer 1

Most common cause of endogenous hyperthyroidism.
Triad of symptoms:
Optholmopathy (exophtholomos)
Dermopathy (pretibial myxedema)
hyperthyroidism (diffuse enlargement of gland)

Age - 20-40 yes women

Question 2

Exoptholmous reasons (in Graves)

Answer 2

It’s due to increased volume of retro orbital connective tissue & extra ocular muscles:

Reasons:
① infiItration of mononuclear cells (tcells) into retroorbital space
② inflammation with edema & swelling of extra ocular muscles
③ accumulation of ECM components glucosaminoglycans ( hyaluronic acid, chondriting olphate)
④ increased no of adipocytes

Orbit fibroblasts express TSH receptor

CD 4 + th cells → secrete cytokines → fibroblasts proliferate → increase synthesis of glycosaminoglycans → Optholmopathy

Question 3

Morphology of Graves disease.

Answer 3

Diffuse hypertrophy & hyperplasia of thyroid.

On cut surface- parenchyma has soft meaty appearance like muscle

Histology: The follicular epithelial cells are tall And more crowded.
This crowding forms papillae which project into lumen &encroach on colloid filling the follicles
The colloid is pale & scalloped.
Hypertrophy of heart → ischemic changes
Optholmopathy. → fibrosis & edema → infiltration by lymphocytes&mocopolysach
Dermopathy → thickening of Dermis → due to deposition of glycosaminoglycans

Question 4

Medullary carcinoma def

Answer 4

These are neuroendocrine tumors derived from c cells (Para follicular) that secrete calcitonin
Tumor cells can also secrete serotonin, VIP,ACTH
Men 2a &2b,RET mutations

Question 5

Morphology of medullary carcinoma

Answer 5

Sporadic tumor-solitary nodule
Familial - bilateral & multicentric

Areas of necrosis hemorrhage & extend through capsule
Firm, pale grey tan tumor

Micro: polygonal to spindle shaped cells form nests & follicles.
Acellular amyloid deposits derived from polypeptide calcitonin secreted by tumor cells seen in stroma. Calcitonin seen readily in cytoplasm of tumor cells as granules.

C-cell hyperplasia in surrounding parenchyma - precursor of familial tumors

like all neuroendocrine tumors have membrane bound e dense granules in cytoplasm of neoplastic cells.