Pituitary Pathology

Question 1

What is a primary endocrine disorder?

Answer 1

Indicates that there is an issue within the organ the condition is named for (ex. Primary hyperthyroidism indicates problem in the thyroid)

Question 2

What is a secondary endocrine disorder?

Answer 2

Indicates that the issue is occurring outside the organ

Question 3

What is the MC form of primary endocrine hyperfunction?

Answer 3

Neoplasia (except thyroid)

Question 4

What is the embryologic development of the pituitary gland?

Answer 4

Rathke’s pouch and infundibular process forms —>neck of Rathke’s pouch is constricted by growth of mesoderm —> Rathke’s pouch pinched off —> pinched off segment conforms to neural process, forming pars distalis, pars intermedia and pars tuberalis —> pars tuberalis encircles infundibular stalk and the mature form of the gland is formed

Question 5

What is the neurohypophysis?

Answer 5

Posterior lobe of the pituitary gland

Question 6

What is the adenohypophysis?

Answer 6

Anterior lobe of the pituitary gland

Question 7

What is the posterior lobe of the pituitary gland composed of?

Answer 7

Axonal neurons and supportive pituicytes (neuroglial cells)

Question 8

What cells comprise the anterior lobe of the pituitary gland?

Answer 8

Acidophils (GH and prolactin); basophils (TSH, LH/FSH, ACTH); chromophobe (any but smaller amounts)

Question 9

What is a microadenoma?

Answer 9

Pituitary adenoma with that is less than 1cm

Question 10

What is a macroadenoma?

Answer 10

Pituitary adenoma that is 1-4cm

Question 11

What is a giant adenoma?

Answer 11

Pituitary adenoma >4cm

Question 12

What does it mean if a pituitary adenoma is functional?

Answer 12

Hormone excess

Question 13

What does it mean if a pituitary adenoma is non functional?

Answer 13

Mass effect

Question 14

What are the pathology characteristics of pituitary adenomas?

Answer 14

Will show a range of appearances (can be one cell type or multiple); soft and well circumscribed usually; will have uniform monotonous cells of whatever cell makes up the tumor; diffuse growth

Question 15

How can you determine what type of cell is present in a pituitary adenoma?

Answer 15

Clinical presentation, blood tests for hormones levels or pathology stains (hormone stains help delineate tumor type or stains for TFs)

Question 16

What are causes of hyperprolactinemia in the absence of an adenoma?

Answer 16

Pregnancy, lactation/nipple stimulation, loss of dopamine —> lactotroph hyperplasia, renal failure (increased production and decreased clearance of PRL) or hypothyroidism (increased TRH can stimulate PRL production)

Question 17

What can cause lactotroph hyperplasia?

Answer 17

Damage to neurons (stroke, head trauma), drugs (antipsychotics or antidepressants with blockage of dopamine receptors, verapamil, metoclopramide), or a mass

Question 18

What is the lactational amenorrhea method (LAM)?

Answer 18

Relies on elevations of prolactin levels to maintain anovulation (after pregnancy)

Question 19

What are the features of Cushing’s syndrome?

Answer 19

Central obesity, DM, hirsutism, adrenal hyperplasia —> hypercortisolism

Question 20

What is the MCC of Cushing’s syndrome?

Answer 20

Iatrogenic cause due to glucocorticoid administration

Question 21

How do pituitary adenomas (Cushing’s dz) respond to a dexamethasone suppression test?

Answer 21

Responsive (cortisol levels are suppressed)

Question 22

How do SCC respond to a dexamethasone suppression test?

Answer 22

Stubborn (cortisol levels are not suppressed)

Question 23

What are the characteristics of adenomas?

Answer 23

Well circumscribed, can erode bone, can bleed

Question 24

What are the characteristics of aggressive adenomas?

Answer 24

Poorly circumscribed, can invade the brain, more likely as the adenomas get bigger

Question 25

What are the characteristics of a pituitary carcinoma?

Answer 25

Rare; can metastasize or spread through the brain

Question 26

What are some causes of hypopituitarism?

Answer 26

Tumors/mass lesions/cysts, TBI/hemorrhage, surgery/radiation, apoplexy, ischemic necrosis/Sheehan syndrome, inflammatory disorders, genetic defects, squashed, killed off (ischemia, inflammation, surgery), bled into