Nuts and bolts of endocrine system - pathology

Question 1

What is the functional unit of endocrine glands?

Answer 1

cuboidal secretory cells with a lumen at centre (not all endocrine functional units have lumen e.g. pituitary and parathyroid glands)

Question 2

What are the cells of the anterior pituitary gland?

Answer 2

acidophils – take up acidic dyes
basophils – take up basic dyes
chromophobe – no specific staining features

Question 3

What are the features of pituitary adenomas?

Answer 3

Benign tumours, arise from anterior lobe.
can be functional or non-functional.
productive adenomas cause hyperpituitarism.
pressure effect causes hypopituitarism.

Question 4

What are the space-occupying effects of functional or non-functioning pituitary adenomas?

Answer 4

Headaches, vomiting, nausea, diplopia, impaired vision

Question 5

What are the features of the thyroid gland?

Answer 5

Very vascular.
endothelial cells lining capillaries are fenestrated which allows passage of hormones into circulation.
para-follicular cells or C cells are found between follicles and secrete calcitonin which promotes reduction of calcium concentration in blood.

Question 6

What are the pathologies of the thyroid gland and what are their causes?

Answer 6

Goitre - euthyroid
Grave’s disease - hyperthyroid
Hashimoto’s disease - hypothyroid
Adenoma - euthyroid
Cancer - euthyroid

Question 7

What is a multi-nodular goitre caused by?

Answer 7

Lack of iodine leads to goitre due to hyperplasia and hypertrophy of thyroid cells. gland enlarges to maximise amount of iodine absorbed. increase in size overcomes hormone deficiency so patients are euthyroid.

Question 8

What can a multi-nodular goitre cause?

Answer 8

Tracheomalacia - collapse and obstruction of airway due to softening of trachea

Question 9

What is Graves’ disease and what can it cause?

Answer 9

Diffuse enlargement of thyroid gland – goitre due to hyperplasia of thyroid cells.
Infiltrative opthalmopathy – accumulation of soft tissue and inflammatory cells behind eye leading to proptosis
Infiltrative dermopathy – thickening and induration of skin on anterior shin leading to pre-tibial myxoedema.

Question 10

What is the cytology of Graves’ disease?

Answer 10

colloid has ‘soap bubble’ appearance due to hyperactivity

Question 11

How does Hashimoto’s thyroiditis affect thyroid cells and hormones?

Answer 11

Progressive depletion of thyroid cells by inflammation and replaced by fibrosis.
Low T3/T4, high TSH.

Question 12

Outline the histology of Hashimoto’s thyroiditis

Answer 12

prominent lymphocytic infiltrate

Question 13

What are the different types of thyroid tumours?

Answer 13

Follicular adenoma: benign tumour of thyroid follicular cells.
Carcinoma:
papillary - high risk of lymph node metastasis.
follicular - high risk of mets to bone, lung and liver.
medullary - arises from C cells, 20% associated with MEN2.
Anaplastic - older patients, poor prognosis.

Question 14

Which pathologies of the parathyroid glands causes hypercalcaemia?

Answer 14

adenoma and hyperplasia

Question 15

What are the pathologies of the adrenal glands?

Answer 15

Adrenocortical hyperactivity:
hyperplasia, adenoma or cancer 
Cushing’s syndrome (excess cortisol)
Conn’s syndrome (excess aldosterone)
adrenogenital syndrome (excess androgens)
Adrenocortical insufficiency:
Addison’s disease

Question 16

Which hormones are secreted from the anterior pituitary gland and what are the target organs?

Answer 16

GH - bones
Prolactin - mammary gland
ACTH - adrenal glands
FSH and LH - ovaries and testis 
TSH - thyroid gland