Endocrine Pathology: Pituitary

Question 1

Hyperpituitarism

1. Define
2. Causes
3. What determines the clinical manifestation?

Answer 1

1. condition where one or more hormones are secreted in excess by the pituitary gland
2. neoplasm of the anterior lobe or (rarely) a pathologic change in the hypothalamus
3. the hormone(s) that is/are secreted

Question 2

Pituitary Pathology

1. Release of what is increased in pregnancy?
2. Addison’s disease?
3. What happens with microadenomas?
4. What kind of adenoma causes problems?

Answer 2

1. prolactin/GH
2. ACTH
3. very common, often asymptomatic
4. macroadenomas

Question 3

Problems with Macroadenomas

4. Which kind of macroadenoma is found earlier? Functional or non-functional? why?

Answer 3

Usually mass effects (along with release of hormone)

1. secondary hydrocephaly
2. doesn’t invade nearby vessels (internal carotids) but can push/move them aside;
3. may cause strokes due to turbulent flow
4. functional, production of hormones often causes other symptoms; nonfunctional only cause symptoms by their mass

Question 4

Pituitary Histo

1. normal
2. What is seen in adenoma?
3. What % of adenomas are benign?

Answer 4

1. well defined glands
2. normal architecture (reticulin network) is lost, but cells are not malignant
3. 99%

Question 5

Pituitary Adenomas

1. Most common types
2. How many different kinds of hormones does 1 adenoma usually make?

Answer 5

1. Prolactin cell, Growth hormone cell, ACTH (main 3)

2. usually make just 1

Question 6

Somatotrophic adenoma

1. What does it secrete?
2. What is measured?
3. Symptoms

Answer 6

1. growth hormone
2. IGF-1; not GH
3. Gigantism in children before closure of epiphyseal plates; acromegaly occurs in adults- enlargement of head, hands, feet, jutting jaw, large tongue, enlargement of soft tissues

Question 7

Prolactinoma

1. What does it secrete?
2. What does it do in females?
3. What does it do in males?
4. Which gender presents earlier?
5. Which is more common, functioning or non-functioning prolactinomas?

Answer 7

1. Prolactin
2. galactorrhea, hypogonadism leading to amenorrhea
3. causes hypogonadism –> impotence and infertility
4. Women; amenorrhea is picked up earlier
5. non-functioning

Question 8

Corticotroph tumor

1. What does it secrete?
2. What does a Basophilic adenoma cause?
3. What does a chromophobic adenoma cause?
4. What is Nelson syndrome? how do you get it?

Answer 8

1. ACTH
2. causes Cushing’s syndrome due to hypersecretion of the adrenal cortex;
3. may just cause local pressure changes
4. adenoma and pigementaion; following surgical removal or destruction of adrenals

Question 9

What is the difference between Cushing’s syndrome and Cushing’s disease?

Answer 9

Cushing’s syndrome is caused by excess cortisol

Cushing’s disease is hypersecretion of cortisol from the adrenal cortex

Question 10

Pituitary Adenomas

1. What is a null cell adenoma?
2. Roughly what % of adenomas are sporadic?
3. What % are due to MEN I syndrome?
4. Mutations in sporadic?
5. Mutations in MEN 1?

Answer 10

1. heterogenous group of tumors that secretes no hormone at all
2. 97%
3. 3%
4. mutation in alpha subunit of G protein that leads to constitutively activated cAMP
5. MEN1 gene on chromosome 11

Question 11

Hypopituitarism

1. Define
2. Usual cause (in general)
3. Examples

Answer 11

1. condition where the secretion of one or more anterior pituitary hormones is decreased causing a wide range of clinical findings
2. destructure process which affects the pituitary gland
3. Nonsecretory adenomas, pituitary apoplexy (infarction/hemorrhage), Sheehan’s snydrome

Question 12

Hypopituitarism: Nonsecretory Adenomas

1. what % of pituitary adenomas?
2. Clinical manifestations

Answer 12

1. 25%; (Hormone + and Null cell types)

2. reflect local effects (compression of the optic chiasma causing a visual field defect);

Question 13

Hypopituitarism: Sheehan’s Syndrome

1. AKA
2. What happens?
3. Incidence is higher in what pts?
4. Who else can get it?
5. What % destruction leads to symptoms?

Answer 13

1. Postpartum pituitary necrosis
2. obstetrical hemorrhage –> hypotension –> vasospasm –> ischemic necrosis
3. pts w/ long standing diabetes mellitus
4. nonpregnant men and women can also get it;
5. 75%

Question 14

Empty Sella Syndrome

1. Describe Primary type
2. Describe Secondary type

Answer 14

1. defect in diaphragm of the sella leads to CSF leak; increased CSF pressure around pituitary gland causes atrophy
2. sella appears empty, but there is usually enough pituitary tissue to prevent total pituitary insufficiency

Question 15

Other Causes of Hypopituitarism (3 main groups)

Answer 15

1. Exogenous injury (head trauma, radiation)
2. Inflammatory (Sarcoid, lymphocytic hypophysitis)
3. Hypothalamis lesions/dysfunction (uncommon)

Question 16

Posterior Pituitary Syndromes
1, Takes what form?
2. What does a deficiency of what it secretes cause?
3. What does an excess cause?
4. What else can cause an excess?

Answer 16

1. increased or decreased ADH
2. ADH deficiency causes diabetes insipidus (polyuria, polydipsia, and excessive thirst)
3. Inappropriate ADH secretion (increased water absorption and retention, expanded extracellular fluid volume, unable to excrete it as urine)
4. small cell carcinoma can secrete ADH as a paraneoplastic syndrome

Question 17

Craniopharyngioma

1. Arises from what?
2. Malignant or Benign?
3. Where can it be located?
4. Histo looks like what?
5. Who gets it?

Answer 17

1. vestigial remnants of Rathke’s pouch
2. benign
3. most are suprasellar, some can be intrasellar
4. resemble enamel organ of the tooth
5. children/young adults and individuals >60 (bimodal)

Question 18

Craniopharyngioma

1. Clinical presentation
2. Histo look

Answer 18

1. pan Hypopituitarism, diabetes insipidus

2. basaloid/squamous differentiation

Question 19

Rathke's Cleft Cysts
1. Histo look
2. Treatment
Dermoid Cyst
3. Histo look

Answer 19

1. lined by cuboidal epithelium with cilia and/or goblet cells
2. Removed surgically
3. squamous epithlium, can be a teratoma