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Flashcards in Pathology of Endocrine System Deck (44)
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1
Q

What is the definition of hyperplasia and atrophy?

A

Hyperplasia:

Increased number and secretory activity of cells

Atrophy:

Diminution of cells due to lack of stimulation

2
Q

What are important general considerations to make about disease in an endocrine gland?

A

May have multiorgan effects

May lead to altered activity of another endocrine gland

Feedback effects may cause changes in endocrine gland

Endocrine glands have high reserve capacity

3
Q

What hormones does the thyroid gland release?

A

Thyroxine (T4)

Triiodothyronine (T3)

Calcitonin

4
Q

What is the role of epithelial cells in the thyroid gland?

A

Thyroglobulin synthesis

Iodination

Resorption

Release of T4 and T3

5
Q

What is the histological findings of grave’s disease?

A

Increased cell activity

Increased cell numbers

6
Q

What mediates the destruction of the thyroid in hashimotos thyroiditis?

A

Autoimune destruction of thyroid epithelial cells

  • Cytotoxic T cells, cytokine and antibody mediated destruction
  • Circulating autoantibodies to thyroglobulin, thyroid peroxidase
7
Q

What are the histological findings of hashimotos hypothyroidism?

A

Hurthle cell change

Intense infiltrate of plasma cells

Lymphocytes

8
Q

What causes a goitre to become multinodular?

A

Something results to cause impaired synthesis of T3/T4 - (iodine deficiency or goitrogens)

To compensate the thyroid produces more TSH, this results in hypertrophy and hyperplasia of epithelium

Single becomes multi-nodular

9
Q

What are the features of multinodular goitre on histology?

A

Follicles are crowded and filled with colloid (distended)

Haemorrhage, fibrosis, cycstic change

Nodular appearance

10
Q

What might a dominant nodule be?

A

Cyst

Follicular Adenoma

Carcinoma (papillary, follicular, anaplastic, medullary)

Lymphoma (may result from hashimoto’s)

11
Q

What are the relevant investigations for thyroid nodule?

A

TFT’s

Ultrasound

FNA

12
Q

What are the features of a thyroid follicular adenoma?

A

Most are non-functioning

Encapsulated tumour

Circumscribed

13
Q

What are the features of follicular cell carcinoma?

A

Rare

Usually solitary

Malignant cells breach capsule

Mets - bone, blood (previous lecture also said lungs)

14
Q

Give an example of the cause of follicular cell carcinoma

A

RAS mutation

PAX8/PPARG transolcation

15
Q

What is the aetiology of papillary carcinoma?

A

BRAF mutation

RET/PTC gene rearrangement

Associated with exposure to ionizing radiation

16
Q

How does papillary carcinoma spread?

A

Via lymphatics

17
Q

What are the histological findings of papillary carcinoma?

A

Papillary projections

Empty nuclei

Psammoma bodies

May be cystic

18
Q

What cells does a thyroid medullary carcinoma arise from?

A

C- cells

19
Q

What does a medullary carcinoma produce?

A

Calcitonin and maybe other peptides

20
Q

What is medullary carcinoma associated with?

A

MEN 2A, 2B

Familial FMTC

Mutations in RET proto-oncogene

21
Q

What are the histological findings of medullary carcinoma?

A

Amyloid deposits

22
Q

What are causes of primary hyperparathyroidism?

A

Sporadic or Familial (MEN - 1)

Adenoma (common)

Hyperplasia

Carcinoma (rare)

23
Q

What are causes of secondary parathyroidism?

A

Physiological response to reduced calcium - renal failure?

24
Q

What is the role of the hypothalamus and the pituitary?

A

Hypothalamus - homeostasis and emotional behaviour

Pituitary gland - regulated other endocrine glands

25
Q

What are acidophils and what do they secrete?

A

Stain pink! Acidophils exist in the anterior pituitary

Secrete GH and PRL

26
Q

What are basophils?

A

Found in the anterior pituitary

Secrete ACTH, LH, FSH, TSH

27
Q

What is the third type of cell found in the anterior pituitary?

A

Chromophobes

28
Q

What is the most common cause of pituitary hyperfunction?

A

Pituitary adenoma

Carcinomas are rare

29
Q

What is the cause of pituitary adenoma?

A

5% are inherited (MEN1)

Usually sporadic

30
Q

What are the effects of pituitary adenoma?

A

Adenomas of the pituitary are classified according to the hormone produced by the neoplastic cells

Prolactinoma (galactorrhoe and menstrual disorders)

GH secreting (acromegaly or gigantism)

ACTH secreting - cushing’s disease

Non-functioning - 25-30% of detected tumours

If large - pressure effect - (radiographic abnormalities, visual field abnormalities, elevated intracranial pressure, compression damage - hypopituitarism)

31
Q

What causes pituitary hypofunction?

A

Compression by tumours

(craniopharyngioma - metastatic)

Trauma

Infection (rare) - TB sarcoidosis

Post - partum ischaemic necrosis (sheehan’s syndrome)

32
Q

What do the following portions of the adrenal crotex secrete?

A

Zona glomerulosa: Mineralcorticoids aldosterone

Zona fasciculata: Glucocorticoids cortisol

Zona reticularis: sex steroids, oestrogen, androgens

33
Q

What are the casues of conn’s?

A

Bilateral idiopathic hyperplasia

Functioning adrenal adenoma

Secondary - Renovascular hypertension, diuretic use, renin-secreting tumour, malignant hypertension, coarctation of the aorta

34
Q

What causes adrenogenital syndromes?

A

Functioning adrenal tumour

Pituitary tumour (cushings)

Congenital adrenal hyperplasia (steroid enzyme deficiency - 21-hydroxylase)

35
Q

What causes acute adrenal insufficiency?

A

Meningococcal septicaemia

36
Q

What are the causes of chronic adrenal insufficiency?

A
37
Q

What is the result of a hyperadrenal syndrome (adenoma on cortex) on the adjacent cortex?

A

Causes atrophy

38
Q

How does an adrenal adenoma compare to an adrenal carcinoma?

A

Adenoma - small (usually 2-3 cm), yellow-brown and circumscribed

Carcinoma - more likely to be functional, usually large (over 20cm) = haemorrhage, necrosis, cystic

39
Q

Describe the metastasis of adrenal carcinoma

A

By lymphatics and blood

Invades adrenal vein

Metastatic carcinoma to lung and breast

40
Q

What is multiple endocrine neoplasia?

A

Inherited disorder with underlying genetic mutation

Neoplasms or hyperplasia of endocrine organs

41
Q

What causes MEN1?

A

Tumour suppressor gene mutation - defect in menin protein involved in regulating cell growth

42
Q

What are the features of MEN1?

A

Parathyroid hyperplasia and adenomas

Pancreatic and duodenal endocrine tumours (hypoglycaemia and ulcers)

Pituitary adenoma (prolactinoma)

43
Q

What causes MEN2?

A

RET proto-oncogene mutations

44
Q

What are the features of MEN 2?

A

Medullary carcinoma of thyroid

Phaeochromocytoma

MEN 2A

  • Parathyroid hyperplasia

MEN 2B

  • Neuromas of skin and mucous membrane, skeletal abnormalities
  • Younger patients, aggressive