E2L23-24 Endocrine: Pituitary Pathoma

Question 1

Define functional vs nonfunctional in terms of pituitary tumors and their characteristics

Answer 1

Nonfunctional: do not produce hormones, often present with mass effect, cause bitemporal hemianopsia by compressing the optic chiasm, hypopituitarism from compressing normal tissue, headache

Functional: produces hormone according to the cell type it is

Question 2

Patient is diagnosed with the most common pituitary tumor. What S/Sx will be present in males and females and what is the treatment?

Answer 2

Prolactinoma
High prolactin causes low GnRH and thereby low LH/FSH
Females: Galactorrhea, Amenorrhea
Males: decreased libido, headache

Treatment: dopamine agonist to shrink the tumor by negative feedback, then surgery if needed

Question 3

Patient presents with enlarging bones of hands, feet, and jaw and tongue. What pituitary adenoma do they have, and what complications are you worried about and what treatment is available?

Answer 3

Growth Hormone Adenoma causing gigantism in kids and acromegaly in adults
Not only does bone grow but so does the viscera–leads to dysfunction including heart failure
High levels of GH cause increased blood glucose by inducing gluconeogenesis and inhibiting glucose uptake. This leads to secondary DM
Treatment: Octreotide, GH receptor antagonist, sugery

Question 4

How is acromegaly diagnosed?

Answer 4

Looking for elevated GH and IGF-1 as well as a lack of GH suppression by oral glucose

Question 5

Patient recently gave birth and is having trouble with lactation and reports a loss of pubic hair and fatigue. What condition could be causing this?

Answer 5

Sheehan syndrome

Question 6

Describe Sheehan Syndrome

Answer 6

During pregnancy, high hormone demand causes the pituitary to double in size, but the blood supply does not increase proportionately. During delivery, a loss of blood can lead to infarction in the pituitary. Classic presentation is poor lactation, loss of pubic hair, fatigue

Question 7

On imaging patient with SSx of hypopituitarism appears to have no pituitary. What might have caused this?

Answer 7

Called Empty sella syndrome

Herniation of the arachnoid and CSF compress the pituitary and destroy the gland

Question 8

What hormones are released by the posterior pituitary and where are they made and what do they do?

Answer 8

ADH: promotes free water retention from the distal tubules of the kidney
Oxytocin: uterine contraction and milk let-down

Both actually made in the hypothalamus

Question 9

Describe Central Diabetes Insipidus

Answer 9

Diabetes= high urine flow (peeing too much)
Diabetes Insipidus= polyuria, polydypsia

Central cause can be hypothalamus or pituitary
Deficiency of ADH causes dilute urine that will not concentrate even if fluid intake is restricted

Treat with desmopression–an ADH analog

Question 10

How are central and nephrogenic diabetes insipidus different?

Answer 10

Nephrogenic is caused by impaired renal response to ADH that can be caused by Lithium or Demeclocycline
Major difference is that nephrogenic will not respond to desmopression because the kidney cannot respond to ADH

Question 11

Patient brought in because of mental status changes and seizures. Labs show hyponatremia and there is Hx of small cell carcinoma of the lung. What pituitary related problem is going on and how is it treated?

Answer 11

SIADH
Hyponatremia can be a sign of dilute blood and dysfunction of the distal tubules in the kidney. This can be caused by too much ADH. One cause of this is small cell carcinoma of the lung. Other causes are CNS trauma, pulmonary infection, and drugs. Low sodium leads to neuronal swelling and cerebral edema leading to mental status changes and seizures.
Treatment involves free water restriction and demeclocycline which impairs the tubule response to ADH