Flashcards in CH15 - Endocrine Pathology Deck (276)
What is the endocrine system?
Group of glands that maintain body homeostasis
How does the endocrine system function?
by release of hormones that travel via blood to distant organs
In the endocrine system, what controls hormone release?
Feedback mechanisms control hormone release.
What is pituitary adenoma?
Benign tumor of anterior pituitary celts
Is the pituitary adenoma functional or nonfunctional?
May be functional (hormone-producing) or nonfunctional (silent)
What do nonfunctional pituitary adenoma tumors often present with?
mass effect resulting in bitemporal hemianopsia, hypopituitarism, headache
How does bitemporal hemianopsia occur in nonfunctional pituitary adenoma?
Its due to compression of the optic chiasm
How does hypopituitarism occur in nonfunctional pituitary adenoma?
due to compression of normal pituitary tissue
What do functional pituitary adenoma tumors present with?
Features are based on the type of hormone produced.
What does Prolactinoma presents as?
galactorrhea and amenorrhea (females) or as decreased libido and headache (males)
What is the most common type of pituitary adenoma?
What is the treatment of prolactinoma?
Treatment is dopamine agonists (eg bromocriptine or cabergoline) to suppress prolactin production (shrinks tumor) or surgery for larger lesions.
What is seen in growth hormone cell adenoma?
Gigantism in children, acromegaly in adults, diabetes mellitus
What is seen in growth hormone cell adenoma in children?
Gigantism in children; increased linear bone growth (epiphyses are not fused)
What is seen in growth hormone cell adenoma in adults?
Acromegaly in adults;1) Enlarged bones of hands, feet, and jaw 2) Growth of visceral organs leading to dysfunction (e.g., cardiac failure) 3) Enlarged tongue
Why is secondary diabetes mellitus often present in growth hormone cell adenoma?
GH induces liver gluconeogenesis
How is growth hormone cell adenoma diagnosed?
by elevated GH and insulin growth factor-1 (IGF-1) levels along with lack of GH suppression by oral glucose
What is the treatment for growth hormone cell adenoma?
It is octreotide (somatostatin analog that suppresses GH release), GH receptor antagonists, or surgery.
What is seen in ACTH cell pituitary adenomas?
they secrete ACTH leading to Cushing syndrome
What pituitary adenoma tumors occur rarely?
TSH cell, LH-producing, and FSH-producing adenomas occur, but are rare
What is hypopituitarism?
Insufficient production of hormones by the anterior pituitary gland
When do symptoms for hypopituitarism arise?
when > 75% of the pituitary parenchyma is lost
What are the causes for hypopituitarism?
1) Pituitary adenomas (adults) or craniopharyngioma (children) 2) Sheehan syndrome 3) Empty sella syndrome
What is a cause for hypopituitarism in children?
What is a cause for hypopituitarism in adults?
What are pituitary adenomas (adults) or craniopharyngioma (children) resulting in hypopituitarism due to?
mass effect or pituitary apoplexy (bleeding into an adenoma)
In hypopituitarism, what is sheehan syndrome?
pregnancy-related infarction of the pituitary gland
In Sheehan syndrome, what happens?
The gland doubles in size during pregnancy, but blood supply does not increase significantly; blood loss during parturition precipitates infarction.
What does Sheehan syndrome present as?
poor lactation, loss of pubic hair, and fatigue